WO2013115312A1 - Electrical device module - Google Patents

Description

Electrical device module

The present invention relates to an electric device module such as a battery module, and particularly to an apparatus for cooling an electric device such as a battery.

In JP2009-272048A, a battery module is configured by using a plurality of so-called laminate-type batteries in which a rectangular flat power generation element is covered with a laminate film as a battery exterior material and the peripheral portions of the laminate film are joined by thermal fusion. What to do is disclosed. In this case, the first adhesive material having thermal conductivity is applied to the central part of the laminate type battery, and the second adhesive material having adhesive strength is applied to the peripheral part of the laminate type battery, and the two laminate type batteries are attached. They are laminated together.

Some rectangular flat laminate-type batteries have four sides and take out a positive electrode tab and a negative electrode tab for charging / discharging the power generation element from only one side. When a group of researchers including the present inventors experimented with this, it has been found for the first time that the side with the positive electrode tab has a higher temperature distribution than the side with the negative electrode tab. That is, a non-uniform temperature distribution occurs in the plane of the laminated battery. When there is such a non-uniform temperature distribution, a difference in deterioration progress occurs in the surface of the battery, and the life and reliability of the entire battery are lowered.

Even if the technique described in JP2009-272048A is applied to the above battery having a temperature distribution in which the side having the positive electrode tab has a higher heat generation temperature than the side having the negative electrode tab, the temperature distribution in the battery surface is not uniform. It is not possible to make the in-plane temperature of the battery uniform. This is because the technique described in JP2009-272048A is only a technique that considers that heat radiation from a square flat battery as a whole is higher in the central part than in the peripheral part.

Therefore, the present invention provides an electric device module that can make the in-plane temperature of an electric device uniform even if the electric tab has a temperature distribution in which the side having the positive electrode tab has a higher heat generation temperature than the side having the negative electrode tab. With the goal.

In one embodiment of the present invention, the electrical device module includes a rectangular flat electrical device having four sides, from which a positive electrode tab and a negative electrode tab are aligned and taken out. A laminated body is configured by alternately laminating a plurality of electric devices and flat heat transfer materials in which the positive electrode tab and the negative electrode tab are taken out in the same direction, and storing the laminated body inside the module case, Of the two sides adjacent to the side from which the positive electrode tab and the negative electrode tab are taken out, a cooling body is provided along the side on the positive electrode tab side, and the heat transfer material and the cooling body are brought into contact with each other.

Embodiments of the present invention and advantages of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a schematic perspective view of a lithium ion secondary battery according to a first embodiment of the present invention. FIG. 2 is an exploded perspective view of the power generation element according to the first embodiment of the present invention. FIG. 3 is a model diagram showing a surface temperature gradient of the laminate film during discharge of the battery according to the first embodiment of the present invention. FIG. 4A is a front view of the battery module according to the first embodiment of the present invention. FIG. 4B is a front view of the battery module according to the first embodiment of the present invention. FIG. 5 is a plan view of the battery module according to the first embodiment of the present invention. FIG. 6 is a schematic perspective view of a water jacket and a laminate housed in the battery module according to the first embodiment of the present invention. FIG. 7A is a front view of the battery module according to the second embodiment of the present invention. FIG. 7B is a front view of the battery module according to the second embodiment of the present invention. FIG. 8 is a plan view of the battery module according to the second embodiment of the present invention. FIG. 9A is a front view of a battery module according to a third embodiment of the present invention. FIG. 9B is a front view of the battery module according to the third embodiment of the present invention. FIG. 10 is a plan view of the battery module according to the third embodiment of the present invention. FIG. 11 is a front view of the battery module according to the fourth embodiment of the present invention. FIG. 12 is a plan view of the battery module according to the fourth embodiment of the present invention. FIG. 13 is a front view of the battery module according to the fifth embodiment of the present invention. FIG. 14 is a plan view of a battery module according to a fifth embodiment of the present invention. FIG. 15A is a front view of a battery module according to a sixth embodiment of the present invention. FIG. 15B is a front view of the battery module according to the sixth embodiment of the present invention. FIG. 16 is a plan view of the battery module according to the sixth embodiment of the present invention. FIG. 17A is a front view of a battery module according to a seventh embodiment of the present invention. FIG. 17B is a front view of the battery module according to the seventh embodiment of the present invention. FIG. 18 is a plan view of the battery module according to the seventh embodiment of the present invention. FIG. 19A is a front view of a battery module according to an eighth embodiment of the present invention. FIG. 19B is a front view of the battery module according to the eighth embodiment of the present invention. FIG. 20 is a plan view of the battery module according to the eighth embodiment of the present invention. FIG. 21 is a table summarizing the resistance increase rate before and after the durability test of the comparative example and the example of the present invention. FIG. 22 is a table summarizing the capacity retention rates during the durability test of the comparative example and the example of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the dimension ratio of drawing has the location exaggerated on account of description, and the location differs from the actual ratio.

(First embodiment)
The lithium ion secondary battery 1 according to the first embodiment of the present invention will be described. FIG. 1 is a schematic perspective view of a lithium ion secondary battery 1, and FIG. 2 is an exploded perspective view of a power generation element 2.

As shown in FIG. 1, a lithium ion secondary battery 1 has a structure in which a substantially square flat power generation element 2 in which a charge / discharge reaction actually proceeds is sealed inside a laminate film 14 that is a battery exterior material. Have. Specifically, the power generation element 2 is housed and sealed by using a polymer-metal composite laminate film as a battery exterior material and joining the peripheral portions 14a, 14b, 14c, and 14d by thermal fusion. is doing. A laminate film generally has a three-layer structure in which a metal film is sandwiched between polymer films (resin films).

The laminated battery 1 thus configured is referred to as a “laminated battery” in order to be distinguished from a can-type battery. A can-type battery is one in which two electrodes are wound and housed in a rigid cylindrical metal outer frame. On the other hand, a laminate type battery is a battery in which a power generation element is sealed by joining the peripheral portions of a substantially square flat power generation element 2 by heat fusion. Hereinafter, the lithium ion secondary battery 1 is referred to as a “laminate battery”. Or simply called “battery”.

As shown in FIG. 2, the power generation element 2 has a configuration in which a negative electrode 4, a separator 12, and a positive electrode 8 are stacked in this order. The negative electrode 4 is obtained by disposing negative electrode active material layers 6 and 6 on both sides of a square plate-like negative electrode current collector 5. Similarly, the positive electrode 8 is obtained by disposing positive electrode active material layers 10 and 10 on both sides of a rectangular thin plate-shaped positive electrode current collector 9. The separator 12 is mainly formed from a porous thermoplastic resin. Since the separator 12 holds the electrolytic solution, an electrolyte layer is formed integrally with the separator 12. In other words, an electrolyte layer having a function as a Li ion transfer medium between two electrodes is composed of a liquid electrolyte and a microporous membrane separator 12 containing a resin.

Thus, the adjacent negative electrode 4, separator 12 (including the electrolyte) and positive electrode 8 constitute one single cell layer 13 (single cell). In the single cell layer 13, electrons and ions move between the two electrodes to perform a charge / discharge reaction (electrochemical reaction) of the battery. Therefore, it can be said that the laminate type battery 1 of the present embodiment has a configuration in which the single battery layers 13 are stacked to be electrically connected in parallel. A seal portion (insulating layer) for insulating between the adjacent negative electrode current collector 5 and positive electrode current collector 9 may be provided on the outer periphery of the unit cell layer 13. The outermost negative electrode current collectors 5 located on both outermost layers of the power generating element 2 are all only on one side (in FIG. 2, the uppermost negative electrode current collector 5 has only the lower surface, the lowermost negative electrode current collector 5 has Is disposed on the upper surface only). Note that the arrangement of the negative electrode and the positive electrode is reversed from that in FIG. 2 so that the outermost positive electrode current collector is positioned in both outermost layers of the power generation element 2, and the positive electrode is provided only on one side of the outermost positive electrode current collector. An active material layer may be disposed.

The negative current collector 5 and the positive current collector 9 are attached with two high-power tabs, a negative electrode tab 15 and a positive electrode tab 16, which take out electrons entering and exiting from each electrode (negative electrode and positive electrode) to the outside, and a peripheral portion of the laminate film 14. So as to be sandwiched between the laminated films 14. Since the power generation element 2 is formed in a rectangular flat shape having four sides as a whole, the two high-power tabs 16 and 15 are aligned from only one side of the four sides and led to the outside (see FIG. 1). The high voltage tabs 16 and 15 are ultrasonically applied to the negative electrode current collector 5 and the positive electrode current collector 9 of each electrode via a positive electrode terminal lead (not shown) and a negative electrode terminal lead (not shown) as necessary. You may attach by welding and resistance welding. In addition, it cannot be overemphasized that each negative electrode tab 15 in FIG. 2 and each positive electrode tab 16 are electrically connected.

In order to investigate the temperature gradient in the in-plane direction of the battery 1, a researcher group including the present inventor produced the battery 1 in which the positive electrode tab 16 and the negative electrode tab 15 are aligned and taken out from only one side, and laminated by charging and discharging. When the film surface temperature was measured, the result shown in FIG. 3 was obtained. FIG. 3 shows a model of the surface temperature gradient of the laminate film during discharge, which was first discovered by a group of researchers including the present inventor.

FIG. 3 shows that the darker the color, the higher the laminate film surface temperature due to heat generation. That is, the heat generation temperature is highest in the vicinity of the positive electrode tab 16, and from the high voltage tabs 16 and 15 to the peripheral edge portion 14c opposite to the peripheral edge portion 14a from which the high voltage tabs 16 and 15 are taken out (rightward in FIG. 3). B) The exothermic temperature tends to decrease as the distance increases.

Therefore, the entire battery 1 is divided into a first region and a second region. The first region is a region 17 having a temperature distribution in which the heat generation temperature is highest in the vicinity of the positive electrode tab 16 and the heat generation temperature decreases as the distance from the positive electrode tab 16 increases. The second region is a region 18 having a temperature distribution in which the heat generation temperature is highest in the vicinity of the negative electrode tab 15 and the heat generation temperature decreases as the distance from the negative electrode tab increases. Hereinafter, the first region is referred to as “battery positive electrode tab side region”, and the second region is referred to as “battery negative electrode tab side region”. Thus, when the in-plane of the battery 1 is divided into the battery positive electrode tab side region 17 and the battery negative electrode tab side region 18, the battery positive electrode tab side region 17 as a whole region has a heat generation temperature higher than the battery negative electrode tab side region 18. It is high.

The analysis of this phenomenon is as follows. That is, the use of the battery 1 is accompanied by heat generation. This heat generation is roughly divided into charge / discharge reaction heat (electrochemical reaction heat), polarization heat generation, and Joule heat generated when electrons diffuse in the member. In the battery 1 including the two high-power tabs 16 and 15 for entering and exiting electrons, current (electrons) concentrates in the vicinity of the high-power tabs 16 and 15 due to its structure, and a temperature rise due to Joule heat generation occurs locally. I think that.

In this way, the heat generation temperature is higher on the side where the positive electrode tab 16 is present in the plane of the battery 1 than on the side where the negative electrode tab 15 is present, that is, a non-uniform temperature gradient (temperature distribution) occurs in the in-plane direction of the battery 1. Then, the vicinity of the high voltage tabs 16 and 15 which are the hottest portions will deteriorate first. A difference in the degree of progress of deterioration occurs in the in-plane direction of the battery 1, resulting in a problem that the life and reliability of the entire battery 1 are lowered. Here, the “battery surface” refers to the upper and lower surfaces of the flat paper when the battery is regarded as a single flat paper. The “in-plane direction of the battery” refers to an arbitrary direction along the plane of the flat paper when the battery is regarded as one flat paper. The “in-plane direction of the battery” is also simply referred to as “in-plane direction”.

In the first embodiment of the present invention, a plurality of batteries 1 and flat heat transfer materials 61 in which the take-out directions of the two high-voltage tabs 16 and 15 of the positive electrode tab 16 and the negative electrode tab 15 are aligned in the same direction are alternately stacked. Thus, the laminated body 60 is configured, and the laminated body 60 is accommodated inside the module case 22 and, at the same time, the side on the positive electrode tab 16 side of the two sides adjacent to the side from which the two high voltage tabs 16 and 15 are taken out ( That is, the water jacket 41 (cooling body) is provided along the battery positive electrode tab side region 17), and the heat transfer materials 61 and the water jacket 41 are brought into contact with each other. This will be described in detail below.

4A and 4B are front views of the battery module 21 of the first embodiment, FIG. 5 is a plan view of the battery module 21 of the first embodiment, and FIG. 6 is a water housed inside the battery module 21 of the first embodiment. 3 is a schematic perspective view of a jacket 41 and a laminated body 60. FIG.

The battery module 21 has a module case 22 made of metal such as aluminum. As shown in FIGS. 4A and 4B, the module case 22 has an open end 23a, a lower case 23 that can store four batteries 1 from the open end 23a, and a lid-like cover that covers the open end 23a of the lower case 23. An upper case 31 is included. When the opening end 23a is vertically upward, the lower case 23 has a bottom wall 24 vertically below, left and right walls 25 and 26 connected to the bottom wall 24, and a front wall 27 (a side wall in front of the paper surface in FIGS. 4A and 4B). 5) and a rear wall 28 (see FIG. 5) which is a side wall at the back of the page.

In this embodiment, a box-shaped water jacket 41 is provided on the bottom wall 24 of the lower case 23 so as to substantially cover the entire bottom wall 24. In the space above the water jacket 41, as shown in FIGS. 5 and 6, the laminated body 60 in which the four batteries 1 and the five heat transfer materials 61 are alternately laminated so that the lamination direction becomes the horizontal direction. And store. In this case, the four batteries 1 are aligned such that the high-voltage tabs 16 and 15 are taken out in the same direction (leftward in FIGS. 5 and 6). Each battery 1 is adjacent to the positive electrode tab 16 out of the two peripheral portions 14b and 14d adjacent to the peripheral portion 14a from which the high voltage tabs 16 and 15 are taken out as shown in FIGS. 4A and 4B. It is housed in a state where the peripheral edge portion 14d is set vertically downward.

In order to clarify the positional relationship between each battery 1 and the water jacket 41 in the laminate 60, the front wall 27, which is the side wall in front of the paper surface, and the heat transfer material 61 provided in front of the paper surface in FIG. 4A are removed. Show. Therefore, in FIG. 4A, one surface 1a (see FIG. 5) of the battery 1 is visible on the front.

Similarly, in order to clarify the positional relationship between the heat transfer material 61 and the water jacket 41 in the laminate 60, in FIG. 4B, the front wall 27, which is the side wall in front of the paper surface, the outermost layer heat transfer material 61 on the front side in the paper surface, and The state where the battery 1 on the front side of the paper is removed is shown. Therefore, in FIG. 4B, one surface 61a (see FIG. 5) of the heat transfer material 61 is visible on the front.

Each of the five heat transfer materials 61 is formed in a square plate shape substantially the same as the outer shape of the battery 1, and the two vertical surfaces 61 a and 61 b of the heat transfer material 61 are transferred to the heat transfer material 61 as shown in FIG. 5. The material 61 is brought into close contact (contact) with the two vertical surfaces 1a and 1b of the battery 1 adjacent to each other. As shown in FIG. 5, the heat transfer material 61 is arranged in the outermost layer of the laminate 60, and one of the outermost heat transfer materials 61 (the lowermost heat transfer material in FIG. 5) is the front wall 27. Then, the other outermost layer heat transfer material 61 (the uppermost heat transfer material in FIG. 5) contacts the rear wall 28. As shown in FIGS. 4B and 6, the lower surface 61 c of each heat transfer material 61 is brought into close contact (contact) with the upper surface 42 c of the water jacket case 42.

Each heat transfer material 61 transfers heat transferred from each battery 1 to the water jacket 41. The heat transfer material 61 can be made of a metal having high thermal conductivity such as copper, aluminum, or SUS. A synthetic resin or ceramic may be used as long as it is a substance other than a metal as long as it has a high thermal conductivity.

Although the water jacket 41 was provided along the battery positive electrode tab side area | region 17 (refer FIG. 4A), the reason is as follows. That is, since the battery positive electrode tab side region 17 has a higher heat generation temperature than the battery negative electrode tab side region 18, the battery positive electrode tab side region 17 having a higher heat generation temperature is cooled by the water jacket 41 via the heat transfer material 61. is there.

In the first embodiment, a simple heat generation model is considered for the heat generation state of the battery 1. That is, the heat generation temperature in the battery positive electrode tab side region 17 is relatively higher than the battery negative electrode tab side region 18, and the heat generation temperature is considered to be constant in each of the regions 17 and 18.

When considering the battery 1 with such a simple heat generation model, the heat transfer material 61 is also divided into two regions as follows. That is, in FIG. 4B, the heat transfer material 61 has a lower half region (hereinafter referred to as “heat transfer material positive electrode tab side region”) 62 having the positive electrode tab 16 and an upper half region (hereinafter referred to as “heat transfer material”). It is referred to as “material negative electrode tab side region”) 63. At this time, the heat transfer amounts in the two regions 62 and 63 are different as follows. That is, since the heat transfer material positive electrode tab side region 62 is in contact with the water jacket 41, the heat transfer material negative electrode tab side region 63 is far from the water jacket 41, so that the heat transfer material negative electrode tab side region 63 is more conductive than the heat transfer material negative electrode tab side region 63. The amount of heat transfer is larger in the heat material positive electrode tab side region 62. The difference in heat transfer amount between the two regions 62 and 63 is represented by the difference in arrow length in FIG. 4B.

The heat transfer material positive electrode tab side region 62 is in contact with the battery positive electrode tab side region 17 where a relatively large amount of heat is generated. Therefore, much heat generated in the battery positive electrode tab side region 17 is efficiently transferred to the water jacket 41 via the heat transfer material 61 in the heat transfer material positive electrode tab side region 62 having a relatively large heat transfer amount (FIG. 4B). See the long arrow).

On the other hand, the battery negative electrode tab side region 18 generates relatively less heat than the battery positive electrode tab side region 17. A heat transfer material negative electrode tab side region 63 having a relatively small heat transfer amount is in contact with the battery negative electrode tab side region 18 that generates relatively little heat. Therefore, a small amount of heat generated in the battery negative electrode tab side region 18 is transmitted to the water jacket 41 through the heat transfer material 61 in the heat transfer material negative electrode tab side region 63 having a relatively small heat transfer amount (short arrow in FIG. 4B). reference).

That is, a relatively large amount of heat generated in the battery positive electrode tab side region 17 is quickly released to the water jacket 41 via the heat transfer material 61 in the heat transfer material positive electrode tab side region 62. On the other hand, relatively little heat generated in the battery negative electrode tab side region 18 is not quickly transmitted to the water jacket 41 via the heat transfer material 61 in the heat transfer material negative electrode tab side region 63. The battery positive electrode tab side region 17 takes more heat than the battery negative electrode tab side region 18. Thereby, the temperature in the battery positive electrode tab side region 17 and the temperature in the battery negative electrode tab side region 18 can be made substantially the same, that is, the in-plane temperature of the battery 1 can be made uniform.

The water jacket 41 is for taking heat generated by the four batteries 1 included in the laminate 60 through the five heat transfer materials 61. The water jacket 41 includes a case 42 having an internal space, an inlet pipe 45 (inlet) opened to the case 42 on the side where the positive electrode tab 16 and the negative electrode tab 15 are located, and a case 42 on the side away from the positive electrode tab 16 and the negative electrode tab 15. It is comprised with the exit pipe 46 (exit) opened in this.

The water jacket 41 is provided with an inlet pipe 45 that penetrates the left wall 26 of the module case 22 and an outlet pipe 46 that penetrates the right wall 25 of the module case 22. One end of the inlet pipe 45 opens to the left wall 42 a of the water jacket case 42, and the other end opens to the outside of the left wall 26. One end of the outlet pipe 46 opens to the right wall 42 b of the water jacket case 42, and the other end opens to the outside of the right wall 25. The material of the water jacket case 42 is preferably a metal such as copper, aluminum or SUS having a high thermal conductivity. The water jacket case 42 may be made of the same material as the heat transfer material 61.

In order to flow (circulate) the cooling water in the inner space of the water jacket case 42 from the side where the positive electrode tab 16 and the negative electrode tab 15 are located to the side away from the positive electrode tab 16 and the negative electrode tab 15, the heat exchanger 49 and the cooling water supply A cooling water circulation device including a pipe 50 (supply passage), a cooling water supply pump 51, a return pipe 53 (return passage), connection connectors (47, 48, 52, 54) and the like is provided.

Connectors 47 and 48 (female) are connected to the opening end of the left wall 26 of the inlet pipe 45 and the opening end of the right wall 25 of the outlet pipe 46 as shown in FIGS. 4A and 4B.

The heat exchanger 49 cools the heated cooling water by exchanging heat with the atmosphere. A connector 52 (male) coupled to the connector 47 is connected to the tip of the cooling water supply pipe 50 from the heat exchanger 49, and a connector coupled to the connector 48 is connected to the tip of the return pipe 53 to the heat exchanger 49. 54 (male) is provided. The connector 47 and the connector 52 are coupled, the connector 48 and the connector 54 are coupled, and the cooling water supply pump 51 is driven, whereby the water cooled by the heat exchanger 49 is supplied to the water jacket 41. . The cooling water whose temperature has risen inside the water jacket 41 is returned to the heat exchanger 49 by the return pipe 53 and cooled.

Although the cooling water is mentioned as the coolant supplied to the water jacket 41, it is not limited to this. There are liquid refrigerants and gas refrigerants. As the liquid refrigerant, for example, an antifreeze or LLC (Long Life Coolant) can be used in addition to water. Air can be used as the refrigerant gas.

Here, the function and effect of this embodiment will be described.

The battery 1 of the present embodiment includes a rectangular flat battery 1 (electric device) having four sides and taking out the positive electrode tab 16 and the negative electrode tab 15 from only one side thereof, and includes two high-power tabs 16 and 15. A stack 60 is formed by alternately stacking a plurality of batteries 1 and flat heat transfer materials 61 that are aligned in the same direction, and the stack 60 is housed inside the module case 22 and 2 The water jacket 41 (cooling body) is provided along the side on the positive electrode tab 16 side (that is, the battery positive electrode tab side region 17) out of the two sides adjacent to the side from which the two high voltage tabs 16 and 15 are taken out. The material 61 and the water jacket 41 are brought into contact with each other. The battery 1 of the present embodiment has a relatively large temperature difference from the water jacket 41 at the battery portion on the side where the positive electrode tab 16 is present, so that a relatively large amount of heat is taken away by the water jacket 41. Since the temperature difference with the water jacket 41 is relatively small at the battery portion on the side where the negative electrode tab 15 is present, relatively little heat is taken away by the water jacket 41. Thereby, the in-plane temperature of the battery 1 can be made uniform.

According to this embodiment, the cooling body includes a case 42 having an internal space, an inlet pipe 45 (inlet) that opens into the case 42 on the side where the positive electrode tab 16 and the negative electrode tab 15 are located, and the positive electrode tab 16 and the negative electrode tab 15. A heat exchanger 49 that cools the cooling water (refrigerant), and the cooling water cooled by the heat exchanger 49 is supplied to the inlet pipe 45. Cooling water supply pipe 50 (supply passage) leading to (case inlet) and return pipe 53 (return passage) for returning the cooling water exiting from outlet pipe 46 (case inlet) to heat exchanger 49 are provided. Water flows from the side where the positive electrode tab 16 and the negative electrode tab 15 are present to the side away from the positive electrode tab 16 and the negative electrode tab 15. For this reason, more heat is taken away in the vicinity where the tabs (15, 16) are located than in the part away from the tabs (15, 16). This also makes it possible to make the in-plane temperature of the battery 1 uniform.

(Second Embodiment)
7A and 7B are front views of the battery module 21 of the second embodiment, and FIG. 8 is a plan view of the battery module 21 of the second embodiment, which replaces FIGS. 4A, 4B, and 5 of the first embodiment. It is. The same parts as those in FIGS. 4A, 4B, and 5 of the first embodiment are denoted by the same reference numerals.

In order to clarify the positional relationship between each battery 1 in the laminate 60 and the water jacket 41, the front wall 27 which is the side wall in front of the paper surface in FIG. 7A and the heat transfer material 61 provided in front of the paper surface are removed. Show. Therefore, in FIG. 7A, one surface 1a (see FIG. 8) of the battery 1 is visible on the front.

Similarly, in order to clarify the positional relationship between the heat transfer material 61 and the water jacket 41 in the laminate 60, in FIG. 7B, the front wall 27 which is the side wall in front of the paper surface, the heat transfer material 61 in the outermost layer on the front side in the paper surface, and The state where the battery 1 on the front side of the paper is removed is shown. Therefore, also in FIG. 7B, one surface 61a (see FIG. 8) of the heat transfer material 61 is visible on the front.

In the first embodiment, the battery 1 is handled by a simple heat generation model in which the heat generation temperature is different between the battery positive electrode tab side region 17 and the battery negative electrode tab side region 18 and the heat generation temperature is constant in each region. The heat transfer material 61 of the embodiment may have a constant thermal conductivity in the plane. Actually, the heat generation state of the battery 1 is not simple as shown in FIG. Therefore, in the second embodiment, the in-plane temperature of the battery 1 is changed by changing the thermal conductivity in the plane of the heat transfer material 61 in correspondence with the actual temperature distribution state of the battery 1 shown in FIG. Make uniform.

Here, “heat conduction” means the ease of heat transfer, and “heat conductivity” means the heat flux density (heat energy passing through a unit area per unit time) divided by the temperature gradient in heat conduction. It is a physical quantity. The reciprocal of thermal conductivity is thermal resistivity.

FIG. 7B shows how the thermal conductivity changes in the surface of the heat transfer material 61. That is, in FIG. 7B, the difference in the thermal conductivity is represented by the difference in the density of the five types of colors, and the darker the portion, the higher the thermal conductivity. Thus, the distribution of the thermal conductivity in the surface of the heat transfer material 61 is in accordance with the temperature distribution in the surface of the battery 1 in contact with the heat transfer material 61. That is, according to the temperature distribution image in the surface of the battery 1 as shown in FIG. 3, the temperature is divided into five stages. Therefore, the heat conductivity in the surface of the heat transfer material 61 is divided into five stages according to this temperature distribution. It has been changed.

7B, in the heat transfer material positive electrode tab side region 62, the thermal conductivity is highest in the vicinity where the positive electrode tab 16 is present, and the thermal conductivity decreases as the distance from the positive electrode tab 16 increases (toward the right in FIG. 7B). ing. Further, in the heat transfer material negative electrode tab side region 63, the thermal conductivity is highest in the vicinity of the negative electrode tab 15, and the thermal conductivity decreases as the distance from the negative electrode tab 15 (toward the right in FIG. 7). . Further, when viewed at the same distance to the right from the high voltage tabs 16 and 15, the heat conductivity in the heat transfer material positive electrode tab side region 62 is higher than the heat conductivity in the heat transfer material negative electrode tab side region 63. It has become.

Thus, when each region 62, 63 has a thermal conductivity distribution in the surface of the heat transfer material 61, the vicinity of the positive electrode tab 16 in the heat transfer material positive electrode tab side region 62 is closer to the positive electrode tab 16. The amount of heat transfer is larger than the far side. The difference in the amount of heat transfer in the region 62 is represented by the difference in arrow length in FIG. 7B.

Similarly, in the heat transfer material negative electrode tab side region 63, the heat transfer amount is larger in the vicinity of the negative electrode tab 15 than in the side away from the negative electrode tab 15. The difference in heat transfer amount in the region 63 is represented by the difference in arrow length in FIG. 7B.

For each of the eight regions having a temperature distribution that decreases from the vicinity where the high-power tabs 16 and 15 are located to the side away from the high-power tabs 16 and 15, in order to remove heat and make the temperature in the plane of each region uniform, You need to take the most heat from the vicinity of the tab. On the other hand, since the least heat is generated from the portion farthest from the high voltage tabs 16 and 15, it is necessary to prevent the little heat from being taken away. For this reason, the upper limit thermal conductivity TCup1 and TCup2 for making the temperature uniform in the vicinity where the high voltage tabs 16 and 15 are present in each of the regions 17 and 18 are also used for making the temperature uniform in the part farthest from the tab. Lower thermal conductivity TClow1 and TClow2 are determined respectively. The upper and lower limit thermal conductivities TCup1, TCup2, TClow1, and TClow2 for each of the regions 17 and 18 can be obtained by matching. Accordingly, in one region 17, the thermal conductivity between the upper and lower thermal conductivity TCup1 and TClow1 determined by the conformity, and in the other region 18 between the upper and lower thermal conductivity TCup2 and TClow2 determined by the conformance, Change.

The most heat is generated in the portion where the high voltage tabs 16 and 15 are present in the surface of the battery 1. A portion having a relatively high thermal conductivity of the heat transfer material positive electrode tab side region 62 and the heat transfer material negative electrode tab side region 63 is in contact with the battery portion where each of the high voltage tabs 16 and 15 is located. For this reason, a lot of heat generated in the battery portion where each high-power tab 16, 15 is efficiently transferred to the water jacket 41 via the heat transfer material 61 in a portion having a relatively high thermal conductivity.

On the other hand, relatively little heat is generated from the portion of the surface of the battery 1 away from the high voltage tabs 16 and 15. A portion of the heat transfer material positive electrode tab side region 62 and a heat transfer material negative electrode tab side region 63 of the battery portion remote from the high voltage tabs 16 and 15 is in contact with a portion having a relatively low thermal conductivity. For this reason, a small amount of heat generated in the battery portion away from each of the high voltage tabs 16 and 15 is transmitted to the water jacket 41 via the heat transfer material 61 in a portion having a relatively low thermal conductivity.

That is, much heat generated in the battery portion where the high voltage tabs 16 and 15 are present is quickly released to the water jacket 41 via the heat transfer material 61. On the other hand, a small amount of heat generated in the battery portion away from the high voltage tabs 16 and 15 is not quickly transmitted through the heat transfer material 61. In each region 62, 63, the battery portion with the high-power tabs 16, 15 loses more heat than the battery portion away from the high-power tabs 16, 15.

Furthermore, when viewed at the same distance to the right from the high voltage tabs 16 and 15, the thermal conductivity in the heat transfer material positive electrode tab side region 62 is higher than the heat conductivity in the heat transfer material negative electrode tab side region 63. Therefore, more heat is taken away from the heat transfer material positive electrode tab side region 62. As a result, the temperature difference between the two regions 62 and 63 can be eliminated and the temperature can be made the same, and the temperature can be made the same in each region 62 and 63 as well. That is, even if the actual temperature distribution of the battery 1 is complicated as shown in FIG. 3, the in-plane temperature of the entire battery 1 can be made uniform.

(Third embodiment)
9A and 9B are front views of the battery module 21 of the third embodiment, and FIG. 10 is a plan view of the battery module 21 of the third embodiment, which replaces FIGS. 7A, 7B, and 8 of the second embodiment. It is. The same parts as those in FIGS. 7A, 7B, and 8 of the second embodiment are denoted by the same reference numerals.

In the second embodiment, the in-plane thermal conductivity of the heat transfer material 61 is changed in accordance with the actual temperature distribution of the battery 1 shown in FIG. As a result, the in-plane temperature of the battery 1 can be made uniform with high precision. On the other hand, as shown in FIG. 7B, the in-plane thermal conductivity distribution of the heat transfer material 61 is complicated, In fact, it may be time-consuming to produce a heat transfer material having such a thermal conductivity distribution.

Therefore, the third embodiment considers an intermediate heat generation model that is not as simple as the first embodiment and not as complex as the second embodiment. That is, it is the same as the second embodiment in that the heat generation temperature is highest in the vicinity of the high power tab and the heat generation temperature decreases as the distance from the high power tab increases, but unlike the second embodiment, the battery positive electrode tab side. The region 17 and the battery negative electrode tab side region 18 are considered to have the same temperature distribution.

Thus, in the exothermic model in which the temperature distribution is considered to be the same in the battery positive electrode tab side region 17 and the battery negative electrode tab side region 18, the distribution of the thermal conductivity in the surface of the heat transfer material 61 is shown in FIG. 9B. It becomes simpler than the distribution of the heat transfer coefficient shown in FIG. 7B of the second embodiment. That is, in the third embodiment, the in-plane thermal conductivity of the heat transfer material 61 may be changed as shown in FIG. 9B.

In FIG. 9B, the difference in the thermal conductivity is represented by the difference in the darkness of the five types of colors, and the darker the portion, the higher the thermal conductivity. In FIG. 9, the thermal conductivity is highest in the vicinity where the high-power tabs 16 and 15 are present, and the thermal conductivity decreases as the distance from the high-power tabs 16 and 15 increases (toward the right in FIG. 9). As described above, when the thermal conductivity distribution is provided in the surface of the heat transfer material 61, the heat transfer amount is larger on the side closer to the high-power tabs 16 and 15 than on the side farther from the high-power tabs 16 and 15. This difference in the amount of heat transfer is represented by the difference in arrow length in FIG. 9B.

In the surface of the battery 1, the most heat is generated in the portions where the high voltage tabs 16 and 15 are present. A portion of the heat transfer material 61 having a relatively high thermal conductivity is in contact with the battery portion having the high-power tabs 16 and 15. For this reason, much heat generated in the battery portion where the high voltage tabs 16 and 15 are present is efficiently transferred to the water jacket 41 via the heat transfer material 61 in a portion having a relatively high thermal conductivity.

On the other hand, relatively little heat is generated from the portion of the surface of the battery 1 away from the high voltage tabs 16 and 15. A portion of the heat transfer material 61 having a relatively low thermal conductivity is in contact with the battery portion away from the high voltage tabs 16 and 15. For this reason, a small amount of heat generated in the battery portion away from the high voltage tabs 16 and 15 is transmitted to the water jacket 41 via the heat transfer material 61 in a portion having a relatively low thermal conductivity.

That is, much heat generated in the battery portion where the high voltage tabs 16 and 15 are present is quickly released to the water jacket 41 via the heat transfer material 61. On the other hand, a small amount of heat generated in the battery portion away from the high voltage tabs 16 and 15 is not quickly transmitted through the heat transfer material 61. The battery portion with each high-power tab 16, 15 takes more heat than the battery portion away from each high-power tab 16, 15. Thereby, the in-plane temperature of the battery 1 can be made uniform also in the third embodiment.

Here, the operational effects of the second embodiment and the third embodiment will be described together.

As described above, in each of the regions 17 and 18 having a temperature distribution that becomes lower from the vicinity of the high-power tabs 16 and 15 toward the side away from the high-power tabs 16 and 15, the temperature in the surface of each region is deprived of heat. In order to make the power uniform, it is necessary to remove the most heat from the vicinity where the high voltage tabs 16 and 15 are located. On the other hand, since the least heat is generated from the portion farthest from the high voltage tabs 16 and 15, it is necessary to prevent the heat from being taken away. For this reason, the upper limit thermal conductivity TCup1 and TCup2 for making the temperature uniform in the vicinity of the high-power tabs 16 and 15 have the lower limit heat for making the temperature uniform at the part farthest from the high-power tabs 16 and 15. Conductivities TClow1 and TClow2 are determined. The upper and lower limit thermal conductivities TCup1, TCup2, TClow1, and TClow2 for each of the regions 17 and 18 can be obtained by matching.

Now, the second and third embodiments in which the thermal conductivity is changed between the upper and lower thermal conductivity thus obtained for each of the regions 17 and 18, and the uniform thermal conductivity between the upper and lower limits. Comparison is made with a heat transfer material having an intermediate value of thermal conductivity (this heat transfer material is referred to as a “reference heat transfer material”). According to the second and third embodiments, the thermal conductivity of the heat transfer material 61 is reduced from the vicinity of the high-power tabs 16 and 15 to the side away from the high-power tabs 16 and 15. More heat can be taken nearby than the reference heat transfer material. The portion farthest from the high voltage tabs 16 and 15 does not need to be deprived of heat by the reference heat transfer material. Thus, in the second and third embodiments, the in-plane temperature of the battery 1 can be made more uniform by the reference heat transfer material.

Further, according to the second embodiment, the electric device of the battery 1 has the highest heat generation temperature in the vicinity of the positive electrode tab 16 and the negative electrode tab 15 in the plane, and the heat generation temperature increases as the distance from the positive electrode tab 16 and the negative electrode tab 15 increases. A battery positive electrode tab side region 17 (first region) having a temperature distribution that tends to be lower and has a temperature distribution in which the heat generation temperature is highest in the vicinity of the positive electrode tab 16 in the surface and the heat generation temperature decreases as the distance from the positive electrode tab 16 increases. The battery positive electrode tab side region is divided into the battery negative electrode tab side region 18 (second region) having a temperature distribution in which the heat generation temperature is highest in the vicinity of the negative electrode tab 15 and the heat generation temperature decreases as the distance from the negative electrode tab 15 increases. When the heat generation temperature of 17 is higher than that of the battery negative electrode tab side region 18, the region facing the battery positive electrode tab side region 17 (first region) of the heat transfer material 61 is defined as the heat transfer material positive electrode tab. The region 62 (third region) and the region facing the battery negative electrode tab side region 18 (second region) are divided as the heat transfer material negative electrode tab side region 63 (fourth region), and the heat transfer material positive electrode tab side region 62, In each region of the heat transfer material negative electrode tab side region 63, the heat conductivity of the heat transfer material 61 is reduced from the vicinity where the high power tabs 16, 15 are away from the high power tabs 16, 15, and the high power tabs 16, 15. Since the heat transfer coefficient in the heat transfer material positive electrode tab side region 62 is made larger than the heat conductivity in the heat transfer material negative electrode tab side region 63 at the same distance from the heat transfer material positive electrode tab side region 62, Even if the calorific value is different between the material negative electrode tab side region 63, the temperature difference between the regions 62 and 63 can be eliminated, and the in-plane temperature of the entire battery 1 can be made uniform.

(Fourth embodiment)
FIG. 11 is a front view of the battery module 21 of the fourth embodiment. FIG. 12 replaces the plan view of the battery module 21 of the fourth embodiment and FIGS. 7B and 8 of the second embodiment. The same parts as those in FIGS. 7B and 8 of the second embodiment are denoted by the same reference numerals.

In the second embodiment described above, the thermal conductivity distribution in the plane of the heat transfer material 61 is shown in FIG. 7B. On the other hand, FIG. 11 of 4th Embodiment shows the structure of the concrete heat-transfer material 61 for producing the distribution of the heat conductivity in the surface of the heat-transfer material 61 shown to FIG. 7B.

In order to show the structure of the heat transfer material 61, FIG. 11 also shows a state in which the front wall 27, which is the side wall in front of the paper, the outermost heat transfer material 61 on the front side of the paper, and the battery 1 on the front side of the paper are removed. ing. Therefore, the heat transfer material 61 can also be seen in the front in FIG. 11, but the heat transfer material 61 is further shown in a cross-sectional view along the line XX shown in FIG. The same applies to FIG. 13 described later.

In the fourth embodiment, a porous material having thermal conductivity (hereinafter simply referred to as “porous material”) is selected as the heat transfer material 61. By changing the porosity of the porous material (the number of pores 71 per unit volume), the thermal conductivity is changed in the plane of the heat transfer material 61. The porous material has a higher thermal conductivity (heat is more easily transmitted) as the porosity is lower, and conversely, the lower the porosity is, the lower the thermal conductivity (heat is less likely to be transmitted). Become). This is because the air present in the holes 71 exerts an effect of heat insulation, and therefore the number of the holes 71 is relatively on the side where the number of the holes 71 is relatively large (the side where the porosity is relatively large). This is because the heat insulation effect is greater than the smaller side (the side with a relatively low porosity).

In FIG. 11, in the heat transfer material positive electrode tab side region 62, the porosity is relatively reduced near the positive electrode tab 16 to facilitate heat transfer, and as the distance from the positive electrode tab 16 increases (to the right in FIG. 11). (The more you go, the greater the porosity), making it harder to transfer heat. Further, in the heat transfer material negative electrode tab side region 63, the porosity is relatively reduced in the vicinity of the negative electrode tab 15 to facilitate heat transfer, and the further away from the negative electrode tab 15 (the more toward the right in FIG. 11). ) Increase the porosity to make it difficult to transfer heat. Further, when viewed at the same distance to the right from the high voltage tabs 16, 15, heat is transferred by making the porosity in the heat transfer material positive electrode tab side region 62 smaller than that in the heat transfer material negative electrode tab side region 63. Make it easier.

As described above, when the porosity distribution is provided in the surface of the heat transfer material 61, the heat transfer amount in the vicinity of the positive electrode tab 16 in the heat transfer material positive electrode tab side region 62 is larger than the side away from the positive electrode tab 16. Becomes larger. The difference in the amount of heat transfer in the region 62 is represented by the difference in arrow length in FIG.

Similarly, in the heat transfer material negative electrode tab side region 63, the heat transfer amount is larger in the vicinity of the negative electrode tab 15 than in the side away from the negative electrode tab 15. A difference in heat transfer amount in the region 63 is represented by a difference in arrow length in FIG.

Thus, by changing the porosity of the porous material, the thermal conductivity can be changed in the plane of the heat transfer material 61.

Examples of the porous material include clay. Clay is a generic term for clay that contains water and contains various clay minerals and moisture. Since many clay minerals are composed of fine particles, when the clay dries, pores are formed between the fine particles. For this reason, several types of clay with different porosity are prepared, these several types of clay are gathered together like a mosaic work, and the shape is adjusted by combining them together, and then the desired porosity can be obtained after drying the shaped clay plate. The heat transfer material 61 having the following distribution can be obtained.

Alternatively, the thermal conductivity can be changed in the plane of the clay plate by using the plasticity of the clay instead of using the porosity of the clay. For example, a hard clay that can be shaped by hand is prepared and formed into a plate shape, and a punch is applied to the surface of the plate-like clay to make a dent. In the vicinity where the high-power tabs 16 and 15 are present, the number of dents punched by punches is relatively reduced, and on the side away from the high-power tabs 16 and 15, the number of pits hit by punches is relatively increased. In other words, the hollow is made into a hole, and the thermal conductivity increases as the number of the recesses decreases (the amount of heat transfer increases), whereas the thermal conductivity decreases as the number of the recesses increases. The amount of heat is small). Thus, the thermal conductivity can be changed in the plane of the clay plate also by changing the number of depressions in the vicinity where the high electric tabs 16 and 15 are located and the side away from the high electric tabs 16 and 15.

The porous material is not limited to clay. For example, a metal plate such as copper or aluminum having high thermal conductivity is prepared, and the number of holes drilled in the metal plate is changed between the vicinity of the high voltage tabs 16 and 15 and the side away from the high voltage tabs 16 and 15. Also, the thermal conductivity can be changed in the plane of the metal plate. That is, the number of holes to be drilled is relatively reduced in the vicinity of the high voltage tabs 16 and 15, and the number of holes to be drilled is relatively increased on the side away from the high voltage tabs 16 and 15.

A drill may be used to make a hole in the metal plate. You may make a through-hole in a metal plate with a drill, or just make a dent on the surface of a metal plate.

According to the fourth embodiment, the heat transfer material 61 is a porous material having heat transfer properties, and the porosity of the porous material is set on the side away from the high power tabs 16 and 15 from the vicinity of the high power tabs 16 and 15. (The right side in FIG. 11) and the porosity in the heat transfer material positive electrode tab side region 62 (third region) at the same distance from the high voltage tabs 16, 15, the heat transfer material negative electrode tab side region. Since the porosity is smaller than the porosity in 63 (fourth region), the thermal conductivity of the heat transfer material 61 in each of the regions 62 and 63 is moved away from the high-power tabs 16 and 15 from the vicinity of the high-power tabs 16 and 15. In addition, the thermal conductivity in the heat transfer material positive electrode tab side region 62 (third region) is changed to the heat transfer material negative electrode tab side region 63 (fourth region) at the same distance from the high voltage tabs 16 and 15. The thermal conductivity in the region) can be made larger.

(Fifth embodiment)
FIG. 13 is a front view of the battery module 21 of the fifth embodiment, and FIG. 14 is a plan view of the battery module 21 of the fifth embodiment, which replaces FIGS. 11 and 12 of the fourth embodiment. The same parts as those in FIGS. 11 and 12 of the fourth embodiment are denoted by the same reference numerals.

In the fourth embodiment, on the assumption that the diameters of the pores 71 of the porous material are all the same, the thermal conductivity in the plane of the heat transfer material 61 is changed by changing the porosity of the porous material. It was something to change. On the other hand, the fifth embodiment is the same in that a porous material is selected as the heat transfer material 61, but unlike the fourth embodiment, by changing the diameter of the pores of the porous material, The thermal conductivity is changed in the plane of the heat material 61. Here, for the sake of simplicity, a hole 72 having a relatively small diameter (hereinafter referred to as “small diameter hole”) 72 and a hole having a relatively large diameter (hereinafter referred to as “large diameter hole”) 73 are used. This will be described in the case of two types of holes. Of course, it is not limited to the case where there are two types of hole diameters.

The heat conductivity increases as the number of small-diameter holes 72 is relatively large and the number of large-diameter holes 73 is relatively small in the porous material (heat is easily transmitted). On the contrary, as the number of small-diameter holes 72 is relatively small and the number of large-diameter holes 73 is relatively large, the thermal conductivity is lowered (heat is hardly transmitted). This is because the air present in the holes 72 and 73 exhibits a heat insulating effect, and therefore the side having more large-diameter holes 73 and fewer small-diameter holes 72 has more small-diameter holes 72 and larger. This is because the heat insulation effect is greater than the side having fewer diameter holes 73.

In FIG. 13, in the heat transfer material positive electrode tab side region 62, heat is easily transferred by relatively increasing the small-diameter holes 72 and relatively decreasing the large-diameter holes 73 near the positive electrode tab 16. . On the other hand, the farther away from the positive electrode tab 16 (the more toward the right in FIG. 11), the smaller the number of small-diameter holes 72 and the larger the number of large-diameter holes 73, thereby making it difficult for heat to be transmitted. Further, in the heat transfer material negative electrode tab side region 63, heat is easily transferred by relatively increasing the small diameter holes 72 and relatively decreasing the large diameter holes 73 in the vicinity of the negative electrode tab 15. On the other hand, the farther away from the positive electrode tab 16 (the more toward the right in FIG. 11), the smaller the number of small-diameter holes 72 and the larger the number of large-diameter holes 73, thereby making it difficult for heat to be transmitted. Further, when viewed at the same distance to the right from the high voltage tab, the number of the small-diameter holes 72 in the heat transfer material positive electrode tab side region is larger than that in the heat transfer material negative electrode tab side region and the heat transfer material positive electrode tab. The number of large-diameter holes 73 in the side region is made smaller than that in the heat transfer material negative electrode tab side region to facilitate heat transfer.

As described above, when the holes 72 and 73 having different diameters are provided in the surface of the heat transfer material 61, the vicinity of the positive electrode tab 16 in the heat transfer material positive electrode tab side region 62 is separated from the positive electrode tab 16. The amount of heat transfer is larger than the other side. A difference in heat transfer amount in the region 62 is represented by a difference in arrow length in FIG.

Similarly, in the heat transfer material negative electrode tab side region 63, the heat transfer amount is larger in the vicinity of the negative electrode tab 15 than in the side away from the negative electrode tab 15. The difference in the amount of heat transfer in the region 63 is represented by the difference in arrow length in FIG.

Thus, the thermal conductivity can be changed within the surface of the heat transfer material 61 by changing the diameter of the pores of the porous material.

Examples of the porous material include clay. Two types of clay with different pore sizes are prepared, and these two types of clay are gathered together like a mosaic and joined together to form a shape. After drying the shaped clay plate, the small-diameter holes and the large-diameter holes are arranged in the desired balance, whereby the heat transfer material 61 having a desired hole diameter distribution can be obtained. .

Alternatively, the thermal conductivity can be changed in the plane of the clay plate by using the plasticity of the clay instead of using the porosity of the clay. For example, a hard clay that can be changed in shape by hand is prepared and formed into a plate shape, and two types of punches having different diameters are punched on the surface of the plate-like clay to make a dent. In the vicinity where there is a strong electric tab, the number of pits to be hit with a small diameter punch is relatively large and the number of pits to be hit with a large diameter punch is relatively small. A relatively small number and a relatively large number of indentations with a large diameter punch. In other words, the recesses are holes, and the thermal conductivity increases (the amount of heat transfer increases) as the number of small-diameter recesses is relatively large and the number of large-diameter recesses is relatively small. On the contrary, as the number of small-diameter recesses is relatively small and the number of large-diameter recesses is relatively large, the thermal conductivity decreases (the amount of heat transfer decreases). In this way, the thermal conductivity can be changed in the plane of the clay plate by changing the vicinity of the high electric tabs 16 and 15, the side away from the high electric tabs 16 and 15, and the diameter of the recess.

The porous material is not limited to clay. For example, the thermal conductivity can be changed by preparing a metal plate such as copper or aluminum having high thermal conductivity and changing the number of two types of holes formed in the metal plate. That is, the number of small holes to be drilled is relatively increased in the vicinity of the high-power tabs 16 and 15 and the number of large-diameter holes is relatively decreased. The number of holes is relatively small and the number of large-diameter holes is relatively large.

To drill holes in a metal plate, drills with two different diameters may be used. You may make a through-hole in a metal plate with a drill, or just make a dent on the surface of a metal plate.

According to the fifth embodiment, the heat transfer material 61 is a porous material having heat transfer properties, and the diameter of the pores of the porous material is changed from the high power tabs 16 and 15 from the vicinity of the high power tabs 16 and 15. While increasing the distance to the far side (right side in FIG. 13), the diameter of the hole in the heat transfer material positive electrode tab side region 62 (third region) is set to the heat transfer material negative electrode at a position away from the high voltage tabs 16 and 15 by the same distance. Since it is smaller than the diameter of the holes in the tab side region 63 (fourth region), the thermal conductivity of the heat transfer material 61 in each of the regions 62 and 63 is made higher than that in the vicinity of the high power tabs 16 and 15. In addition, the thermal conductivity in the heat transfer material positive electrode tab side region 62 (third region) can be reduced at the same distance from the high voltage tabs 16 and 15 in the heat transfer material negative electrode tab side region. 63, which is larger than the thermal conductivity in the fourth region. Kill.

11 of 4th Embodiment and FIG. 13 of 5th Embodiment show the structure of the concrete heat-transfer material 61 for producing the distribution of the heat conductivity in the surface of the heat-transfer material 61 shown to FIG. 7B. It was a thing. Similarly, a specific structure of the heat transfer material 61 for generating the in-plane thermal conductivity distribution of the heat transfer material 61 shown in FIG. 9B can be considered (not shown). For example, the heat transfer material is a porous material having heat transfer properties, and the porosity of the porous material is changed from the vicinity of the high power tabs 16 and 15 to the side away from the high power tabs 16 and 15 in each region 62 and 63. Enlarge. According to this, the heat transfer material 61 is a porous material having heat transfer properties, and the porosity of the porous material is set in the regions 62 and 63 from the vicinity where the high power tabs 16 and 15 are located. Therefore, the thermal conductivity of the heat transfer material 61 in each of the regions 62 and 63 can be reduced from the vicinity of the high-power tabs 16 and 15 to the side away from the high-power tabs 16 and 15.

Further, the heat transfer material 61 is a porous material having heat transfer properties, and the pore diameter of the porous material is changed from the high power tabs 16 and 15 in the vicinity of the high power tabs 16 and 15 in the regions 62 and 63. Increase to the far side. According to this, the heat transfer material 61 is a porous material having heat transfer properties, and the diameter of the pores of the porous material is set to the high-power tabs 16, Since the heat conductivity of the heat transfer material 61 for each of the regions 62 and 63 is increased toward the side away from the high-power tabs 16 and 15, the heat conductivity of the heat transfer material 61 can be decreased from the vicinity of the high-power tabs 16 and 15. .

(Sixth embodiment)
15A and 15B are front views of the battery module 21 of the sixth embodiment, and FIG. 16 is a plan view of the battery module 21 of the sixth embodiment, which replaces FIGS. 4A, 4B, and 5 of the first embodiment. It is. The same parts as those in FIGS. 4A, 4B, and 5 of the first embodiment are denoted by the same reference numerals.

In the sixth embodiment, in order to prevent heat transfer between the adjacent batteries 1, 1, as shown in FIG. 16, the heat transfer material 61 is provided on the mutually opposing surfaces of the adjacent batteries 1, 1. A heat insulating material 81 is sandwiched between two heat transfer materials 61 and 61 that are in contact with each other and in contact with the battery 1. That is, in FIG. 16, the two heat transfer materials 61 to be brought into contact with the mutually facing surfaces of the adjacent batteries 1 and 1 are formed in a square plate shape that is substantially the same as the outer shape of the battery 1. The two vertical surfaces 61 a and 61 b are in close contact with (contact with) the two vertical surfaces 1 a and 1 b of the battery 1. This is the same as in the first embodiment. Further, the heat insulating material 81 sandwiched between the two heat transfer materials 61 and 61 is formed in a square plate shape substantially the same as the outer shape of each of the two heat transfer materials 61 and 61, and the two vertical heat insulating materials 81 are arranged. Each surface 81a, 81b is brought into close contact (contact) with the two vertical surfaces 61a, 61b of the heat transfer material 61 facing each other.

As the heat insulating material 81, for example, a resin such as expanded polystyrene may be used.

According to the sixth embodiment, the heat transfer materials 61 and 61 are brought into contact with the opposing surfaces of the two adjacent batteries 1 and 1, respectively, and the heat insulating material 81 is provided between the two heat transfer materials 61 and 61. Since it is interposed, it becomes possible to prevent the movement of heat between two adjacent batteries 1, 1, and the temperature within the surface of the battery 1 can be made uniform for each battery 1.

In the sixth embodiment, the battery module 21 of the first embodiment is described as a premise, but the present invention is not limited to this. For example, on the assumption of the battery modules 21 of the second to fifth embodiments, the heat insulating material 81 may be added in the same manner as in FIG.

(Seventh embodiment)
17A and 17B are front views of the battery module 21 of the seventh embodiment, and FIG. 18 is a plan view of the battery module 21 of the seventh embodiment, which replaces FIGS. 4A, 4B, and 5 of the first embodiment. It is. The same parts as those in FIGS. 4A, 4B, and 5 of the first embodiment are denoted by the same reference numerals.

In the seventh embodiment, in order to improve the cooling capacity, the heat transfer material 61 is brought into contact with the mutually opposing surfaces of the adjacent batteries 1 and 1 as shown in FIG. A heat transfer material 91 having a higher thermal conductivity than the heat transfer material 61 was sandwiched between the two heat transfer materials in contact with each other. Here, since the two heat transfer materials 61 and 91 come out, in order to distinguish between them, the heat transfer material 61 is referred to as a “first heat transfer material” and the heat transfer material 91 is referred to as a “second heat transfer material”. . That is, in FIG. 18, the two first heat transfer materials 61 to be brought into contact with the mutually opposing surfaces of the adjacent batteries 1 are formed in a square plate shape substantially the same as the outer shape of the battery 1, and each first heat transfer material 61 is formed. The two vertical surfaces 61 a and 61 b are in close contact (contact) with the two vertical surfaces 1 a and 1 b of the battery 1. This is the same as in the first embodiment. In addition, the second heat transfer material 91 sandwiched between the two heat transfer materials is formed in a square plate shape substantially the same as the outer shape of each of the two first heat transfer materials 61, and the vertical length of the second heat transfer material 91. The two surfaces 91a and 91b are in close contact (contact) with the two vertical surfaces 61a and 61b of the first heat transfer material 61 facing each other.

Here, the first heat transfer material 61 can be made of a clay plate as described above, and the second heat transfer material 91 can be made of a metal plate such as copper or aluminum.

According to the seventh embodiment, the first heat transfer materials 61 and 61 are brought into contact with the opposing surfaces of the two adjacent batteries 1 and 1, respectively, and between the two first heat transfer materials 61 and 61. Since the second heat transfer material 91 that is larger than the heat conductivity of the two first heat transfer materials 61 and 61 is interposed, the cooling capacity of the heat transfer material can be improved.

In the seventh embodiment, a combination in which a clay plate is used as the first heat transfer material 61 and a metal plate is used as the second heat transfer material 91 is described, but the present invention is not limited to this. For example, a ceramic plate whose thermal conductivity is higher than that of the first heat transfer material 61 is used as the second heat transfer material 91. The first heat transfer material 61 and the second heat transfer material 91 are both metal plates, and the metal plate (for example, aluminum plate) on the side having a relatively low thermal conductivity is the first heat transfer material 61, and the heat conductivity is relative. In particular, a higher metal plate (for example, a copper plate) can be employed as the second heat transfer material 91.

(Eighth embodiment)
19A and 19B are front views of the battery module 21 of the eighth embodiment, and FIG. 20 is a plan view of the battery module 21 of the eighth embodiment, which replaces FIGS. 4A, 4B, and 5 of the first embodiment. It is. 4A, 4B, and FIG. 5 of the first embodiment are assigned the same numbers.

In addition, in order to clarify the positional relationship between each battery 1 in the laminate 60 and the water jacket 41, the front wall 27, which is the side wall in front of the paper surface, and the heat transfer material 61 provided in front of the paper surface are removed in FIG. 19A. Indicates the state. For this reason, in FIG. 19A, the one surface 1a (refer FIG. 20) of the battery 1 is visible in the front.

Similarly, in order to clarify the positional relationship between the heat transfer material 61 and the water jacket 41 in the laminate 60, in FIG. 19B, the front wall 27, which is the side wall in front of the paper surface, the outermost heat transfer material 61 on the front side in the paper surface, and The state where the battery 1 on the front side of the paper is removed is shown. For this reason, in FIG. 19B, one surface 61a (see FIG. 20) of the heat transfer material 61 is visible on the front.

In the first embodiment, the water jacket 41 is provided inside the module case 22. On the other hand, in the eighth embodiment, the water jacket 41 is provided outside the module case 22. That is, in the eighth embodiment, since the water jacket 41 is not provided in the lower case 23, the laminated body 60 composed of the battery 1 and the heat transfer material 61 is formed on the bottom wall 24 as shown in FIGS. 19A and 19B. Store directly on top.

Each of the five heat transfer materials 61 is formed in a square plate shape that is substantially the same as the outer shape of the battery 1, and the two vertical surfaces 61 a and 61 b of the heat transfer material 61 are formed as shown in FIG. The material 61 is brought into close contact (contact) with the two vertical surfaces 1a and 1b of the battery 1 adjacent to each other. In addition, as shown in FIG. 20, the heat transfer material 61 is arranged in the outermost layer of the laminate 60, and one of the outermost heat transfer materials 61 (the lowermost heat transfer material in FIG. 20) is the front. The wall 27 and the other outermost heat transfer material 61 (the uppermost heat transfer material in FIG. 20) are in contact with the rear wall 28. Further, as shown in FIG. 19B, the lower surface 61 c of each heat transfer material 61 is brought into close contact (contact) with the upper surface 24 a of the lower case bottom wall 24.

On the other hand, the water jacket 41 is provided directly below the lower case bottom wall 24, and the lower surface 24b of the lower case bottom wall 24 is brought into close contact (contact) with the upper surface 42c of the water jacket case 42.

In the eighth embodiment, the lower case bottom wall 24 is interposed between the heat transfer material 61 and the water jacket 41. However, since the lower case 23 itself is made of a metal such as aluminum having heat transfer properties, the heat transferred from the battery 1 to the heat transfer material 61 is transferred to the water jacket 41 through the lower case 23 having heat transfer properties. .

Thus, according to the eighth embodiment, there is provided a rectangular flat battery 1 (electric device) having four sides and taking out the positive electrode tab 16 and the negative electrode tab 15 from only one side, and two strong electric powers are provided. A stack 60 is formed by alternately laminating a plurality of batteries 1 and flat heat transfer materials 61 in which the tabs 16 and 15 are taken out in the same direction to form a metal module case 22 (having heat conductivity). The laminated body 60 is housed inside the module case), and the side on the positive electrode tab 16 side (that is, the battery positive electrode) out of the two sides adjacent to the side from which the two high voltage tabs 16 and 15 are taken out from the outside of the module case 22 A water jacket 41 (cooling body) is provided along the tab side region 17), and each heat transfer material 61 and the water jacket 41 are brought into contact with each other via the module case 22.Also according to the eighth embodiment, since the temperature difference with the water jacket 41 is relatively large in the battery part on the side where the positive electrode tab 16 is present, relatively much heat is taken away, and the battery part on the side where the negative electrode tab 15 is present Then, since the temperature difference with the water jacket 41 is relatively small, relatively little heat is taken away. Thereby, the in-plane temperature of the battery 1 can be made uniform.

<Example 1>
Example 1 is an example of the first embodiment. A stacked body 60 is formed by alternately stacking four batteries 1 in which the positions of the high-voltage tabs 16 and 15 are aligned and five heat transfer materials 61 having uniform thermal conductivity. The stacked body 60 is a module. It arrange | positioned on the water jacket 41 put on the bottom of case 22 (refer FIG. 4A, FIG. 4B, FIG. 5). In this case, the heat transfer material positive electrode tab side region 62 was brought into contact with the water jacket 41 (see FIGS. 4A, 4B, and 6). The cooling water in the water jacket 41 was allowed to flow from the side where the high-power tabs 16 and 15 are located to the side away from the high-power tabs 16 and 15 (see FIGS. 4A and 4B).

<Example 2>
Example 2 is an example of the third embodiment. The configuration of the heat transfer material 61 is different from that of Example 1, and the rest is the same as that of the first embodiment. That is, in Example 2, the heat transfer material 61 is configured so that the thermal conductivity changes as shown in FIG. 9B within the surface of the heat transfer material 61.

<Example 3>
Example 3 is an example of the second embodiment. The configuration of the heat transfer material 61 is different from that of Example 1, and the rest is the same as that of the first embodiment. That is, in Example 3, the heat transfer material 61 is configured so that the thermal conductivity changes as shown in FIG. 7B within the surface of the heat transfer material 61.

<Example 4>
Example 4 is an example of the sixth embodiment. The difference from Example 1 is that a heat insulating material 81 is added, and the rest is the same as in the first embodiment. That is, in Example 4, the heat insulating material 81 is added as shown in FIG.

<Example 5>
Example 5 is an example of the seventh embodiment. The difference from Example 1 is that the two types of heat transfer materials 61 and 91 differ in thermal conductivity, and the rest is the same as in the first embodiment. That is, in Example 5, as shown in FIG. 18, it is set as the two types of heat-transfer materials 61 and 91 (2nd heat-transfer material is an aluminum board | plate material) from which heat conductivity differs.

<Comparative Example 1>
Comparative Example 1 is obtained by removing the heat transfer material and the water jacket from Example 1. That is, in Comparative Example 1, a module case 22 in which four batteries are stacked is stored.

<Evaluation>
The battery modules of Examples 1 to 5 and Comparative Example 1 thus manufactured were subjected to resistance measurement and durability test.

(1) Resistance measurement (initial, after endurance test)
The battery was charged to 4.2 V at a constant current of 0.2 C and then held at 4.2 V (total charging time of 12 hours), then discharged at 3 C, and the resistance value was calculated from the voltage drop after 10 s. Since there are four batteries 1, the resistance value between the high voltage tabs was measured for each battery 1, and the four resistance values were averaged. Measurement was performed at the initial stage and after the durability test of (2) below. The resistance values of Examples 1 to 5 when the initial resistance value of Comparative Example 1 is 100 are shown as a ratio.

The result of resistance measurement is shown in FIG. From FIG. 21, the resistance increase rate after the durability test is as small as 201 to 179% according to Examples 1 to 5, compared with 210% in Comparative Example 1. This means that each battery 1 is not deteriorated in Examples 1 to 5 than in Comparative Example 1.

(2) Durability test A cycle test was performed under the following conditions. That is, the battery was charged to 4.2 V with a constant current of 1.0 C and then held at 4.2 V (total charging for 2 hours). Thereafter, charging was stopped for 10 minutes in the open state. Next, it was discharged to 2.5 V with a constant current of 1.0 C (cut-off). Thereafter, charging was stopped for 10 minutes in the open state.

The results of the durability test are shown in FIG. As shown in FIG. 22, the capacity retention rate at 500 cycles is 72% in Comparative Example 1, which is a large decrease from 100%, whereas in Examples 1-5, it is 75-81%, and the decrease from 100% is small. ing. This also means that the batteries 1 are not deteriorated in Examples 1 to 5 than in Comparative Example 1.

In the embodiment, a lithium ion secondary battery using a laminate film as an exterior material is illustrated as an electrical device, but the present invention is not limited thereto. It can be applied to other types of secondary batteries and even primary batteries. Moreover, it can be applied not only to batteries but also to electrochemical capacitors such as electric double layer capacitors.

As mentioned above, although embodiment of this invention was described, the said embodiment showed only a part of application example of this invention, and it is the main point which limits the technical scope of this invention to the specific structure of the said embodiment. Absent.

This application claims priority based on Japanese Patent Application No. 2012-20606 filed with the Japan Patent Office on February 2, 2012. The entire contents of this application are incorporated herein by reference.

Claims (12)

A square flat electric device having four sides, from which one side of the positive electrode tab and the negative electrode tab are aligned and taken out,
A laminate is configured by alternately laminating a plurality of the electric devices and flat heat transfer materials in which the positive electrode tab and the negative electrode tab are taken out in the same direction,
While storing the laminate inside the module case, a cooling body is provided along the side on the positive electrode tab side of two sides adjacent to the side where the positive electrode tab and the negative electrode tab are taken out,
An electric device module in which each of the heat transfer materials is in contact with the cooling body. A flat electrical device having four sides, from which one side of the positive electrode tab and the negative electrode tab are aligned and taken out,
A laminate is configured by alternately laminating a plurality of the electric devices and flat heat transfer materials in which the positive electrode tab and the negative electrode tab are taken out in the same direction,
The laminated body is housed inside a module case having heat conductivity, and on the side on the positive electrode tab side of two sides adjacent to the side where the positive electrode tab and the negative electrode tab are taken out from the outside of the module case. Along the cooling body,
The electric device module in which each heat transfer material and the cooling body are in contact with each other via the module case. The electrical device module according to claim 1 or 2,
The cooling body includes a case having an internal space, an inlet opening on a side where the positive electrode tab and the negative electrode tab of the case are located, and an outlet opening on a side away from the positive electrode tab and the negative electrode tab of the case. Configured,
A heat exchanger for cooling the refrigerant;
A supply passage for guiding the refrigerant cooled by the heat exchanger to the inlet of the case;
An electric device module comprising: a return passage for returning the refrigerant exiting from the outlet of the case to the heat exchanger. The electrical device module according to any one of claims 1 to 3,
The heat transfer material is an electric device module having a low thermal conductivity from the vicinity of the positive electrode tab and the negative electrode tab toward the side away from the positive electrode tab and the negative electrode tab. The electrical device module according to claim 4,
The heat transfer material is a porous material having heat transfer properties, and the porous material has a large porosity from the vicinity of the positive electrode tab and the negative electrode tab toward the side away from the positive electrode tab and the negative electrode tab. Become an electrical device module. The electrical device module according to claim 4,
The heat transfer material is a porous material having heat transfer properties, and the porous material has a pore diameter from the vicinity of the positive electrode tab and the negative electrode tab toward the side away from the positive electrode tab and the negative electrode tab. An electrical device module that grows. The electrical device module according to any one of claims 1 to 6,
An electric device module in which a heat transfer material comes into contact with opposing surfaces of two adjacent electric devices and a heat insulating material is interposed between the two heat transfer materials. The electrical device module according to any one of claims 1 to 6,
The first heat transfer material abuts against the opposing surfaces of the two adjacent electric devices, and the second heat transfer material has a heat conductivity larger than that of the first heat transfer material between the two first heat transfer materials. 2 An electric device module in which a heat transfer material is interposed. The electrical device module according to any one of claims 1 to 8,
The electrical device module has a high heat generation temperature in the vicinity of the positive electrode tab and the negative electrode tab, and the heat generation temperature tends to decrease as the distance from the positive electrode tab and the negative electrode tab increases. The electric device module according to any one of claims 1 to 4,
The electrical device has a high exothermic temperature in the vicinity of the positive electrode tab and the negative electrode tab, and the exothermic temperature tends to decrease as the distance from the positive electrode tab and the negative electrode tab increases.
The surface of the electrical device has a first region having a temperature distribution in which the heat generation temperature is high near the positive electrode tab and the heat generation temperature decreases as the distance from the positive electrode tab is increased, and the heat generation temperature is high near the negative electrode tab. When the electric device is divided into a second region having a temperature distribution in which the heat generation temperature decreases as the distance from the negative electrode tab increases, the first device has a heat generation temperature higher than that of the second region,
The region of the heat transfer material facing the first region is a third region,
The region of the heat transfer material facing the second region is a fourth region,
The heat transfer material is
The third region and the fourth region are configured to have a low thermal conductivity from the vicinity of the positive electrode tab and the negative electrode tab toward the side away from the positive electrode tab and the negative electrode tab,
The electrical device module in which the third region has a thermal conductivity larger than that of the fourth region at the same distance from the side where the positive electrode tab and the negative electrode tab are located. The electrical device module according to claim 10,
The heat transfer material is a porous material having heat transfer properties, and the porous material has a large porosity from the vicinity of the positive electrode tab and the negative electrode tab toward the side away from the positive electrode tab and the negative electrode tab. And is configured to be
The electrical device module in which the porosity in the third region is smaller than the porosity in the fourth region at the same distance from the positive electrode tab and the negative electrode tab. The electrical device module according to claim 10,
The heat transfer material is a porous material having heat transfer properties, and the porous material has a pore diameter from the vicinity of the positive electrode tab and the negative electrode tab toward the side away from the positive electrode tab and the negative electrode tab. It is configured to be large,
In the electric device module, the diameter of the hole in the third region is smaller than the diameter of the hole in the fourth region at the same distance from the positive electrode tab and the negative electrode tab.

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