WO2016085271A1 - Device and method for measuring thickness of secondary battery cell - Google Patents

Abstract

Provided are a device and method for measuring the thickness of a secondary battery cell. The device according to the present invention comprises: a mounting stand on which a secondary battery cell is positioned; a pressurizing plate which is installed so as to be variable in distance from the mounting stand; a pressurizing means which pushes or pulls the mounting stand toward or from the pressurizing plate; a measurement means for measuring the pressurization force applied to the pressurizing plate by the pressurizing means and the thickness of the secondary battery cell; and a control unit which is configured to control charging, discharging or temperature of the secondary battery cell according to measurement conditions, receive a pressurization force measurement value and a thickness measurement value from the measurement means to thereby determine the size of the pressurization force applied to the pressurizing plate and the thickness of the secondary battery cell, and change or keep the pressurization force applied to the pressurizing plate constant.

Description

Apparatus and method for measuring thickness of secondary battery cell

The present invention relates to a technique for measuring the thickness of a secondary battery cell capable of repeated charging and discharging.

The present invention is based on Korean Patent Application No. 10-2014-0166734 filed with the Korean Patent Office on November 26, 2014 and Korean Patent Application No. 10-2015-0165853 filed on the Korean Patent Office on November 25, 2015. Claiming priority, the contents of the specification and drawings of this application are all incorporated and incorporated as part of this application.

A secondary battery, unlike a primary battery that cannot be charged, refers to a battery that can be repeatedly charged and discharged, and is used as a power source for energy storage systems, electric vehicles, or hybrid vehicles, as well as small portable electronic devices such as mobile phones, PDAs, and notebook computers. It is used.

Secondary batteries are manufactured and used in the form of cells sealed with battery components such as a positive electrode, a negative electrode, a separator, an electrolyte, and various additives in a case. However, in the secondary battery, the thickness of the battery cell may increase due to volume change of various materials such as an electrode active material, electrolyte, and additives, generation of gas, etc. due to chemical reaction during repeated charge and discharge. In addition, such a change in thickness of the battery cell may be caused by heat generated by misuse of the battery such as heat generated during charge and discharge, overcharge, overdischarge, and the like, and heat received by the battery being placed in a high temperature environment.

On the other hand, battery cells are divided into can-type batteries and pouch-type batteries, depending on the shape of the case. The can-type battery contains the above-mentioned components in a rectangular or cylindrical case made of metal, and the pouch-type battery contains the above-mentioned components in a pouch composed of a sheet made of aluminum and laminated with a synthetic resin coating layer. Although can-type batteries have higher physical strength than pouch-type batteries, pouch-type batteries, which are relatively light and easy to manufacture, have been widely used in recent years. However, the pouch-type battery has a disadvantage in that it is particularly vulnerable to the thickness change of the above-described battery cell because of its low physical strength.

As the thickness of the battery cell increases, that is, when the internal pressure of the battery cell increases, the battery cell ruptures at a weak portion of the case, and may lead to an accident such as ignition or explosion of the battery cell. Therefore, in the case of a pouch-type battery cell, the thickness of the battery cell is measured after a predetermined number of charge / discharge cycles or after being left at a high temperature for a predetermined time, whereby the suitability of the pouch-type battery cell and the like Sealability is being tested. Furthermore, as disclosed in Korean Patent No. 10-1397926, the thickness of the battery cell before and after the flexible pouch type battery cell is placed in a vacuum chamber and the vacuum state is formed by using a vacuum pump and the thickness difference of the electrolyte is used. Test the anticipated leakage, ie the sealability of the pouch type battery cell.

On the other hand, the pouch-type battery cell is not used as it is a flexible pouch form. That is, a pouch-type battery cell is stored in a rigid outer case and used as a power supply battery for portable electronic devices, or a plurality of pouch-type battery cells when used as a large capacity battery such as a power storage system or a power source of an electric vehicle or a hybrid vehicle. Is used as a modular battery stacked in a rigid frame. Therefore, the pouch-type battery cell is subjected to a constant pressure by the outer case or frame during actual use or storage. However, in the above-described prior art, since the thickness of the battery cell in the form of a flexible pouch is measured only under fixed conditions, there is a limit in that it is impossible to observe and predict the thickness change of the battery cell during actual use or storage.

The problem to be solved by the present invention is to provide a thickness measuring device and method of the secondary battery cell that can measure and predict the thickness change or the behavior of the secondary battery cell during actual use or storage of the secondary battery cell.

Another problem to be solved by the present invention is an apparatus and method for measuring the thickness of a secondary battery cell capable of observing the behavior of the secondary battery cell or the case or cartridge frame when the thickness change during the actual use or storage of the secondary battery cell is suppressed. To provide.

Device for measuring the thickness of a secondary battery cell according to an aspect of the present invention for solving the above problems, the mounting table on which the secondary battery cell to measure the thickness; A pressure plate facing the mounting table with the secondary battery cell interposed therebetween, and having a variable distance from the mounting table; Pressing means for pressing the secondary battery cell placed on the mounting table in a thickness direction by pushing or pulling the pressing plate toward the mounting table; Measuring means for measuring the pressing force applied to the pressing plate by the pressing means and the thickness of the secondary battery cell; And controlling the charging, discharging, or temperature of the secondary battery cell according to measurement conditions input by an operator, and receiving a pressing force measurement value and a thickness measurement value from the measuring means at intervals of time and the magnitude of the pressing force applied to the pressure plate. A control unit configured to determine a thickness of the secondary battery cell and store it in a memory together with time information, and to maintain or change a pressing force applied to the pressing plate by the pressing means while the thickness of the secondary battery cell is measured. Include.

Preferably, the pressing means, the elastic member of the opposite surface of the surface in contact with the secondary battery cell of both surfaces of the pressure plate to elastically bias the pressure plate; A driving block coupled with the elastic member to push or pull the elastic member along a thickness direction of the secondary battery cell; And a driving unit for raising or lowering the driving block along the thickness direction of the secondary battery cell.

According to one aspect, the measuring means measures the distance between the drive block and the pressure plate at a time interval and outputs the distance measurement value as a pressure measurement value, the control unit inputs the distance measurement value from the measurement means And determine the length of the elastic member, determine the magnitude of the pressing force applied to the pressure plate by the determined length of the elastic member, and store the determined magnitude of the pressing force together with time information in the memory.

According to another aspect, the controller determines the thickness of the secondary battery cell by using the length of the elastic member, the moving distance of the drive block, and the initial distance between the mounting table and the pressure plate, and determines the thickness of the secondary battery cell. And to store in memory together.

Preferably, the controller may be configured to display the change data of the pressing force stored in the memory or the change data of the thickness of the secondary battery cell on the display.

According to another aspect, the measuring means may include a piezoelectric sensor disposed between the surface of the mounting table and the surface of the pressing plate facing the surface of the mounting table to output a thickness measurement value of the secondary battery cell. have.

According to another aspect, the measuring means measures the time it takes to reciprocate between the drive block and the pressure plate by irradiating an optical signal, ultrasonic waves or infrared rays from the drive block or the pressure plate to determine a distance measurement value representing the distance between the drive block and the pressure plate. It may include a distance measuring sensor for outputting.

Preferably, the apparatus according to the present invention further includes a charge / discharge unit for charging or discharging the secondary battery cell, wherein the controller receives a charge / discharge condition from an operator and stores the charge / discharge condition in a memory and stores the charge / discharge condition according to the charge / discharge condition. The discharge unit may be configured to charge and discharge the secondary battery cell.

The apparatus according to the present invention may further include a heater installed on at least one of the pressure plate and the mounting table, and the control unit receives a heating temperature setting value from an operator and stores it in a memory, according to the heating temperature setting value. It can be configured to control the temperature of the heater.

The apparatus according to the present invention may further include cooling means for cooling at least one of the pressure plate and the mounting table, and the control unit receives a cooling temperature setting value from an operator and stores it in a memory, and stores the cooling temperature setting value. Can be configured to control the cooling means in accordance.

According to an aspect of the present invention, a method of measuring a thickness of a secondary battery cell includes: a mounting table on which a secondary battery cell to measure thickness is placed; A pressure plate elastically biased by an elastic member and having a variable distance from the mounting table with the secondary battery cell interposed therebetween; A driving block for pressing the secondary battery cell placed on the mounting table in a thickness direction by pushing or pulling the pressing plate toward the mounting table through the elastic member; A method of measuring the thickness of a secondary battery cell by using the pressing force applied to the pressure plate and the measurement means for measuring the thickness of the secondary battery cell, charging or discharging the secondary battery cell according to the measurement conditions input by the operator Adjusting the temperature of the secondary battery cell; The pressing force measurement value and the thickness measurement value are input from the measuring means at intervals to determine the magnitude of the pressing force applied to the pressure plate and the thickness of the secondary battery cell, and store the magnitude of the pressing force and the thickness together with time information. Storing in; And maintaining or changing a pressing force applied to the pressing plate by the pressing means while the thickness of the secondary battery cell is measured.

While the prior art simply measures the thickness of the cell once under a fixed condition (fixed pressing force), in the present invention, the thickness of the cell can be measured by variously and easily setting the desired pressing force or ambient temperature. Therefore, the thickness change and behavior of the secondary battery cell can be observed under conditions close to the time of actual use or storage, and further, the thickness change of the secondary battery cell can be suppressed and the behavior of the secondary battery cell during use or storage can be suppressed. The physical strength data required for the cartridge frame, the outer case and the pouch can be obtained.

The following drawings appended hereto illustrate one embodiment of the present invention, and together with the following description serve to further understand the spirit of the present invention, the present invention is limited only to those described in such drawings. It should not be interpreted.

1 is a view schematically showing the configuration of a secondary battery cell thickness measuring apparatus according to an embodiment of the present invention.

2 is a view for explaining a process of measuring the cell thickness using the secondary battery cell thickness measuring apparatus according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms, and only the present embodiments are intended to complete the disclosure of the present invention and to those skilled in the art to fully understand the scope of the invention. It is provided to inform you. Configurations shown in the embodiments and drawings described herein are only one of the most preferred embodiments of the present invention and do not represent all of the technical spirit of the present invention, various equivalents that may be substituted for them at the time of the present application It should be understood that there may be variations and examples.

1 is a view schematically showing the configuration of a secondary battery cell thickness measuring apparatus according to an embodiment of the present invention.

The cell thickness measuring apparatus according to the present embodiment includes a mounting table 20, a pressure plate 30, pressing means 40, 42, 44, 46, measuring means 51, 53, and a control unit 60. .

The mounting table 20 is a place where the secondary battery cell 10, which is an object to measure thickness, is placed. The mount 20 is fixed to a frame (not shown) of the cell thickness measuring apparatus or constitutes a part of the frame. The mounting table 20 is made of a material having rigidity such as metal or hard plastic so that the secondary battery cell 10 is not easily recessed or deformed when the secondary battery cell 10 is expanded or pressed by the pressurizing means.

In addition, the mounting table 20 is typically made of a flat plate shape, but the present invention is not necessarily limited thereto. That is, for example, when forming a modular battery by stacking a plurality of secondary battery cells 10 via a cartridge frame therebetween, or putting one secondary battery cell 10 in a rigid outer case, the portable electronic device When the battery for power supply of the battery is configured, the shape of the surface on which the secondary battery cell 10 of the mounting table 20 is placed is the same as the shape of the surface of the cartridge frame or the secondary battery cell 10 of the outer case. You may.

The cell thickness measuring apparatus according to the present embodiment further includes a sheet-type heater 70 installed inside the mounting table 20 and the pressure plate 30 to simulate an environment in which the secondary battery cell 10 is used or stored. can do. Of course, the sheet heater 70 may be provided only on either of the mounting table 20 and the pressure plate 30. The heater 70 adjusts the temperature of the secondary battery cell 10 to a temperature set by an operator according to a control command of the controller 60. The heater 70 is installed to be close to the surfaces of the mounting table 20 and the pressure plate 30 and has an area corresponding to at least the size of the secondary battery cell 10.

The cell thickness measuring apparatus according to the present exemplary embodiment may further include cooling means 80 for cooling the temperature of the secondary battery cell 10 to a temperature set by an operator. The cooling means 80 is installed on at least one side of the mounting table 20 and the pressure plate 30. The cooling means 30 includes a refrigerant flow tube 81 embedded in the mounting table 20 and the pressure plate 30, a circulation pipe 82 for supplying a refrigerant to the refrigerant flow tube 81, and the circulation pipe 82. ) And a temperature control unit 83 that lowers the temperature of the coolant to a temperature set by an operator according to a control signal of the control unit 60, and the circulation pipe 82 and the coolant flow tube according to the control signal of the control unit 60. A pump 84 for circulating the refrigerant through the 81.

The cell thickness measuring apparatus according to the present embodiment may further include a charge / discharge unit 90. The charging and discharging unit 90 charges and discharges the secondary battery cells 10 according to charging and discharging conditions set by an operator according to a control command of the controller 60. For example, the charging and discharging unit 90 may repeat the process of charging the secondary battery cell 10 to the full charge voltage and then discharging the battery to the full discharge voltage by the number of cycles set by the operator. As another example, the charge / discharge unit 90 may charge and discharge the secondary battery cell 10 according to the charge / discharge profile set by the operator. The charge / discharge profile is data that defines the magnitude of the charge current and the magnitude of the discharge current over time. The charge / discharge unit 90 may be used to observe how the thickness of the secondary battery cell 10 changes over time depending on the charge / discharge cycle or the charge / discharge profile.

The charging and discharging unit 90 may include a voltage measuring circuit that measures at least the voltage of the secondary battery cell 10. The charging and discharging unit 90 may provide a voltage measurement value measured by the voltage measuring circuit to the controller 60. The controller 60 may provide the charging and discharging unit 90 with a control command for operating the charging and discharging unit 90 in the charging mode when the voltage measurement value reaches the operation lower limit voltage set by the operator. On the other hand, the controller 60 may provide a control command to the charge / discharge unit 90 to operate the charge / discharge unit 90 in the discharge mode when the voltage measurement value reaches the operation upper limit voltage set by the operator. In addition, the controller 60 may count the charge / discharge cycles of the secondary battery cell 10, and stop the operation of the charge / discharge unit 90 when the counted cycle value reaches a value set by the operator.

In the present embodiment, it is particularly useful that the secondary battery cell 10 to be measured for thickness is a pouch type secondary battery cell that is flexible to some extent and expands and contracts, but the present invention is applicable to a can type secondary battery cell.

Pouch-type secondary battery cell 10 is a pouch consisting of aluminum as a main material and a synthetic resin coating layer laminated sheet, battery components such as positive electrode, negative electrode, separator, electrolyte, and various additives are sealed, and the electrode terminal ( 11, 12) has a protruding sheet shape. Meanwhile, in the drawings, the electrode terminals 11 and 12 protrude to both sides of the pouch-type secondary battery cell 10, respectively, but the protruding position and direction of the electrode terminal may be changed. The electrode terminals 11 and 12 may be electrically coupled to the charge / discharge unit 90.

The pressure plate 30 is installed to face the mounting table 20 with the secondary battery cell 10 interposed therebetween, so that the distance from the mounting table 20 is variable (that is, movable in the vertical direction in the drawing). (Not shown).

In addition, the pressure plate 30 is made of a material having rigidity, such as metal or hard plastic, and is typically made of a flat plate like the mounting table 20, but the surface of the pressure plate 30 on the secondary battery cell 10 in the pressure plate 30. The shape of the surface may be the same as the shape of the surface facing the secondary battery cell 10 of the cartridge frame or the outer case.

The pressing means is a means for pressing the secondary battery cell 10 placed on the mounting table 20 in the thickness direction by pushing or pulling the pressing plate 30 toward the mounting table 20. In this embodiment, the pressing means includes an elastic member 40, a drive block 42 and a screw 44 and a motor 46 as a drive unit.

The elastic member 40 is installed on the upper surface of the pressure plate 30, that is, the surface opposite to the secondary battery cell 10 to elastically bias the pressure plate 30. Although the elastic member 40 is illustrated as two coil springs in the figure, one coil spring or three or more coil springs may be disposed. Furthermore, it may be made of coil springs as well as other elements having elasticity such as leaf springs or rubber.

The drive block 42 is installed on the upper end of the elastic member 40, that is, the end opposite to the pressure plate 30 so as to be lifted up and down to push or pull the elastic member 40 along the thickness direction of the secondary battery cell 10. do. The drive block 42 is made of a material having rigidity, such as metal or hard plastic, like the mounting table 20 and the pressure plate 30, and is typically made of a flat plate, but the specific shape can be changed. In the center of the drive block 42 is formed a screw through hole formed with a screw thread on the inner peripheral surface.

The screw 44 is formed with a thread having the same pitch as the thread formed on the inner circumferential surface of the screw through hole, and is inserted into the screw through hole and screwed to engage with the drive block 42.

The upper end of the screw 44 is fixed to the rotating shaft of the motor 46 fixed to the frame so that the screw 44 rotates in accordance with the rotation of the motor 46, the drive block 42 in accordance with the rotation of the screw 44 It will move up and down. That is, the motor 46 is a drive unit for driving the drive block 42 to move along the thickness direction of the secondary battery cell 10. The lifting motion of the drive block 42 according to the rotation of the motor 46 and the screw 44 is transmitted to the pressure plate 30 via the elastic member 40, so that the pressure plate 30 is placed on the mounting table 20. The secondary battery cell 10 is pressed by a predetermined pressing force.

As the motor 46, one capable of forward and reverse rotation is used to enable the elevating of the drive block 42. A step motor or servo is provided to provide a precisely adjusted pressing force (that is, the elevating amount of the drive block 42). Motors are preferred.

On the other hand, in this embodiment, although the screw 44 is shown and described as being directly fixed to the rotation axis of the motor 46, between the motor 46 and the screw 44, such as a memory box for changing the rotational speed and direction is changed Of course, the delivery device may be interposed. In addition, although the lifting motion of the drive block 42 is realized by the rotation of the motor 46 and the screw 44 in the present embodiment, other mechanisms for converting the rotational motion and the linear motion of the rack and pinion, the worm and the worm gear, etc. In addition, it is also possible to use a linear motion motor, such as a linear motor. Furthermore, in the present embodiment, the motor 46 is used as the driving unit to move up and down the drive block 42. However, instead of the motor, the user uses a knob or handle to adjust the lifting up and down of the drive block 42. It is also possible to directly lift and operate the drive block 42.

The measuring means 51 and 53 are means for measuring the pressing force applied to the pressure plate 30 and the thickness of the secondary battery cell 10 by the above-mentioned pressing means. Specifically, the following means can be used.

First, the pressing force applied to the pressing plate 30, that is, the pressing force may be converted into the elastic force of the coil spring, which is the elastic member 40. That is, when the elastic member 40 is a compression coil spring, the length of the spring 40 is reduced by x by lowering the drive block 42 downward with respect to the length when no force is applied to the spring 40. When the elastic modulus of the spring 40 is k, the elastic force of the spring 40 becomes F = kx, which can be used as the pressing force. Therefore, the pressing force is the distance between the current length, that is, the upper surface of the pressing plate 30 and the lower surface of the driving block 42 in a state where the initial length along the thickness direction of the secondary battery cell 10 of the elastic member 40 is known. Can be measured quantitatively.

Specifically, the pressing force measuring means measures the time taken to reciprocate between the driving block 42 and the pressing plate 30 by irradiating an optical signal, an ultrasonic wave or an infrared ray from the driving block 42 or the pressing plate 30, and the driving block 42. And a distance measuring sensor 51 that outputs a distance measurement value indicating a distance between the pressure plate 30 and the pressure plate 30. In this case, the distance measuring sensor 51 may repeatedly output the distance measurement value as the pressing force measurement value at a time interval.

Preferably, the distance measuring sensor 51 is installed on the lower surface of the driving block 42 (or the upper surface of the pressing plate 30) to cover the upper surface of the pressing plate 30 (or the lower surface of the driving block 42). A transmitting element 51a which emits a distance measuring signal such as a laser, an infrared ray or an ultrasonic wave, and a receiving element which detects a distance measuring signal reflected from the upper surface of the pressing plate 30 (or the lower surface of the driving block 42). 51b and a sensor driver 51c that counts the time it takes for the distance measurement signal to reciprocate between the drive block 42 and the pressure plate 30, and determines the distance measurement value from the counted time and the frequency of the distance measurement signal. ) May be included.

The thickness of the secondary battery cell 10 is equal to the distance between the upper surface of the mounting table 20 and the lower surface of the pressing plate 30 when the secondary battery cell 10 and the pressure plate 30 placed on the mounting table 20 are in close contact with each other. Do. Therefore, as a means for measuring the thickness of the secondary battery cell 10, the piezoelectric sensor 53 disposed between the upper surface of the mounting table 20 and the lower surface of the pressure plate 30 can be used.

The piezoelectric sensor 53 elastically biases the piezoelectric body 53a for generating a voltage signal whose magnitude varies with pressure, the rod 53b movable up and down, and the rod 53b by elastically biasing the piezoelectric body 53a according to the position of the rod 53b. Sensor driver for determining the moving distance of the rod 53b according to the elastic body 53c for varying the pressure applied to the pressure, and the magnitude of the voltage signal, and outputs the thickness measurement value of the secondary battery cell 10 based on this. 53d.

The initial position of the rod 53b is at a position higher than the thickness of the secondary battery cell 10. As the pressure plate 30 descends, when the rod 53b comes into contact with the lower surface of the pressure plate 30 and descends, when the pressure is applied to the piezoelectric body 53a through the elastic body 53c, the piezoelectric body 53a is formed of the rod 53b. Generate a voltage signal with a magnitude corresponding to the falling distance. The generated voltage signal is input to the sensor driver 53d. The sensor driver 53d may determine the magnitude of the received voltage signal and determine a thickness measurement value of the secondary battery cell 10 by using a predefined thickness calculation formula. The thickness equation can be defined by experimenting to find the correlation between the magnitude of the voltage signal and the load fall distance.

According to another aspect, the distance between the upper surface of the mounting table 20 and the lower surface of the pressure plate 30 may be measured using a distance measuring means in the same manner as the distance measuring sensor 51.

According to another aspect, the thickness of the secondary battery cell 10 may be calculated using the distance measuring sensor 51 and the controller 60 without using a separate measuring means 53. That is, the distance measuring sensor 51 can only measure the distance between the upper surface of the pressure plate 30 and the lower surface of the driving block 42, but the distance that the driving block 42 moves from the initial position (the elastic member 40 is If the end portion of the driving block 42 is moved along the thickness direction of the secondary battery cell 10), the initial distance between the upper surface of the pressure plate 30 and the lower surface of the driving block 42, and the driving block ( The thickness of the secondary battery cell 10 may be calculated from the moving distance of 42. Details thereof will be described later with reference to FIG. 2.

The controller 60 controls the overall operation of the cell thickness measuring apparatus. In detail, while measuring the thickness of the secondary battery cell 10, the pressing force measurement value (distance measurement value) and the thickness measurement value of the secondary battery cell 10 are input from the measuring means 51 and 53, and feedback control is performed. The driving of the motor 46 is controlled to allow the pressing force to be applied to the secondary battery cell 10 according to a condition set by the operator.

In particular, in the thickness measurement of the secondary battery cell 10 according to the present invention, while the thickness of the secondary battery cell 10 is measured, the pressing force applied to the secondary battery cell 10 is uniformly maintained according to conditions set by the operator. The thickness of the secondary battery cell 10 is measured under conditions that are as close to the actual use or storage state of the secondary battery cell as possible to maintain or change in a predetermined pattern.

To this end, the controller 60 receives a pressing force profile that changes in a predetermined or predetermined pattern applied to the secondary battery cell 10 during thickness measurement from the operator and stores the pressure profile in the memory 62. The motor 46 may be driven according to the set pressing force application condition by reading the pressing force value stored in 62).

The control unit 60 is an output device for displaying the thickness measurement value of the secondary battery cell 10 and the pressing force measurement value to the user, the display 100, and input means such as a mouse or a keyboard for inputting operator commands or data. 110 may be further provided.

The control unit 60 determines the magnitude of the pressing force applied to the secondary battery cell 10 and the thickness of the cell from the pressing force measurement values and the thickness measurement values input from the measuring means 51 and 53 at intervals of a period, and together with the time information. May be stored in the memory 62.

In addition, the controller 60 may change the thickness change data of the secondary battery cell 10 according to the magnitude of the pressing force and the pressing force according to the thickness of the secondary battery cell 10 by using data stored in the memory 62 at the request of the operator. The change data, the thickness change data of the secondary battery cell 10 over time, or the change data of the pressure force over time may be generated and displayed on the display 100. The information displayed on the display 100 may be a graph, but the present invention is not limited thereto.

The operator may set the conditions for applying the pressing force, whether or not the secondary battery cell 10 is charged or discharged, the number of charge / discharge cycles, the charge / discharge profile, the heating temperature setting value of the secondary battery cell 10, the cooling temperature setting value, and the like. The pressing force application condition may be set to a fixed value or may be set to change with time. Similarly, the heating temperature setpoint value or the cooling temperature setpoint value may be set to a fixed value or set to change with time. To this end, the controller 60 may provide a graphic user interface for inputting various setting values through the display 100.

The controller 60 including the memory 62 may be typically implemented as an electronic circuit or chip such as a microprocessor or a memory device, but the present invention does not necessarily have to include a memory or a controller. That is, the distance between the mounting table 20 and the pressure plate 30 (ie, the thickness of the secondary battery cell) and the distance between the pressure plate 30 and the drive block 42 (ie, the pressing force) can be measured. The scale (ruler) is mounted, and the user can manually control the pressing force and measure the thickness of the secondary battery cell by manually operating the motor 46 or the knob or the handle. In this case, the above-described measuring means 51 and 53 may also be omitted.

2 is a view for explaining the process of measuring the cell thickness using the secondary battery cell thickness measuring apparatus according to an embodiment of the present invention, with reference to Figure 2 the thickness measurement of the secondary battery cell according to the present invention Describe the method.

First, the pressing plate 30 (driving block 42) of the above-described cell thickness measuring device is lifted upward and the secondary battery cell 10 to measure the thickness is placed on the mounting table 20.

Subsequently, the control unit 60 lowers the pressure plate 30 (the driving block 42) so that the pressing force set by the operator is applied to the secondary battery cell 10 (see FIG. 2A).

At this time, the control unit 60 receives the distance measurement value as the pressure measurement value from the distance measurement sensor 51, the distance between the drive block 42 and the pressure plate 30, that is, the length L1 of the elastic member 40. Can be determined. In addition, the controller 60 may adjust the pressing force by feedback-controlling the driving of the motor 46 so that the length L1 of the elastic member 40 corresponds to the set pressing force.

The secondary battery cell thickness measuring apparatus according to the present invention can be used to observe the thickness change and behavior of the secondary battery cell 10 in the actual use state of the secondary battery.

According to one aspect, the controller 60 may control the charging and discharging of the secondary battery cell 10 according to the measurement conditions set by the operator for the secondary battery cell 10 by controlling the charging and discharging unit 90. The measurement conditions may be the number of charge and discharge cycles or the charge and discharge profile. At this time, the control unit 60 continuously or intermittently while the secondary battery cell 10 is being charged or discharged to the thickness measurement value of the secondary battery cell 10 and the pressure plate 30 using the measuring means 51 and 53. The applied force measurement value can be determined. In addition, the controller 60 may store the thickness measurement value and the pressing force measurement value together with the time information in the memory 62. The data stored in the memory 62 may be utilized to determine the correlation between the thickness and the pressing force of the secondary battery cell 10 and the change behavior of the thickness and the pressing force according to the measurement conditions.

According to another aspect, the controller 60 controls the heater 70 or the cooling means 80 around the secondary battery cell 10 with or without charge and discharge of the secondary battery cell 10. The temperature of can be adjusted to the temperature set by the operator. At this time, the controller 60 may continuously or intermittently determine the thickness measurement value of the secondary battery cell 10 and the pressing force measurement value applied to the pressure plate 30 using the measuring means 51 and 53. In addition, the controller 60 may store the thickness measurement value and the pressing force measurement value together with the time information in the memory 62. The data stored in the memory 62 may be utilized to determine the correlation between the thickness and the pressing force of the secondary battery cell 10 and the change behavior of the thickness and the pressing force according to the measurement conditions.

According to the present invention, the thickness of the secondary battery cell 10 may be measured as follows.

In one aspect, the thickness of the secondary battery cell 10 can be measured simply by using a measuring means 53 such as a piezoelectric sensor of the cell thickness measuring apparatus shown in FIG. 1. That is, the controller 60 may determine the thickness of the secondary battery cell 10 by receiving the thickness measurement value of the secondary battery cell 10 from the measuring means 53.

In another example, the thickness of the secondary battery cell 10 may be determined using only the measuring means 51.

First, the distance between the mounting table 20 and the pressing plate 30 in a state in which no force is applied to the pressing plate 30, that is, the elastic member 40 without placing the secondary battery cell 10 on the mounting table 20. Let t0, and the distance between the pressure plate 30 and the drive block 42 is L0, and the sum of the two distances t0 + L0 is the initial position H0 of the drive block 42. At this time, t0 sets the initial position of the driving block 42 to be smaller than the initial thickness of the secondary battery cell 10. In one example, the values for t0, L0 and H0 corresponding to the initial condition may be stored in the memory 62 in advance.

2 (a) shows an initial state in which the secondary battery cell 10 to measure the thickness of the mount 20 is mounted. Since the thickness of the secondary battery cell 10 is greater than t 0, the elastic member 40 is slightly elastically biased while the pressure plate 30 moves upward. Therefore, the pressing plate 30 is in a state in which the secondary battery cell 10 is pressed with a predetermined pressing force. In this state, the conditions L1 <L0 and t1> t0 are established. Since the driving block 42 is not raised and remains at the initial position, the relationship H0 = L0 + t0 = L1 + t1 is established. Therefore, the thickness t1 of the secondary battery cell 10 in the state (a) of FIG. 2 is calculated from a relational expression of t1 = H0-L1 or t1 = L0-L1 + t0. Here, H0, L0, t0 are known values stored in the memory 62. The control unit 60 may determine the distance L1 between the drive block 42 and the pressure plate 30 by using the measuring means 51, and use the distance L1 and H0, L0, t0 stored in the memory 62. The initial thickness t1 of the secondary battery cell 10 may be determined from the equation and stored in the memory 62.

The calculation process of t1 may be continuously or intermittently repeated while charging and discharging the secondary battery cell 10 is in progress and / or while the temperature of the secondary battery cell 10 is adjusted according to a condition set by an operator. Can be.

Subsequently, (b) of FIG. 2 shows a case where the thickness of the secondary battery cell 10 is increased due to expansion. The secondary battery cell 10 may expand when the number of charge and discharge cycles is sufficiently increased or when the ambient temperature of the secondary battery cell 10 is maintained at a high temperature for a long time.

Even in the state (b) of FIG. 2, the drive block 42 maintains the initial position H0 as it is. Therefore, the thickness t2 of the secondary battery cell 10 is calculated from the relational expression of t2 = H0-L2 or t2 = L0-L2 + t0 similarly to the state (a) of FIG. 2. Therefore, the controller 60 may determine the distance L2 between the drive block 42 and the pressure plate 30 by using the measuring means 51, and use the distance L2 and H0, L0, t0 stored in the memory 62. The expansion thickness t2 of the secondary battery cell 10 may be determined from the above equation and stored in the memory 62.

This calculation process t2 may be continuously or intermittently repeated while charging and discharging the secondary battery cell 10 is in progress and / or while the temperature of the secondary battery cell 10 is adjusted according to a condition set by an operator. Can be.

On the other hand, the secondary battery cell is constrained by the cartridge frame in the high capacity modular battery and the outer case in the small battery module mounted on the portable electronic device as described above during actual use or storage. Therefore, the thickness of the secondary battery cell 10 does not increase as much as t2. Figure 2 (c) shows a state that simulates this state using the apparatus according to the present invention.

The controller 60 lowers the driving block 42 by ΔH to simulate the situation in which expansion of the secondary battery cell 10 is prevented by the cartridge frame or the outer case, and the magnitude of the pressing force applied to the pressure plate 30. Can be increased. In this case, since the relationship H0 = L3 + t3 + ΔH is established, the thickness t3 of the secondary battery cell 10 may be calculated from the relational expression of t3 = H0-L3-ΔH. Here, H0 is a known value stored in the memory 62, and ΔH is a value that can be determined from the rotation angle or the rotation speed of the motor 46. The control unit 60 determines the distance L3 between the drive block 42 and the pressure plate 30 using the measuring means 51, determines ΔH from the rotation angle or the rotation speed of the motor 46, and determines the determined distance. The expansion constraint thickness t3 of the secondary battery cell 10 may be determined and stored in the memory 62 using L3 and ΔH and H0 stored in the memory 62.

The calculation process of the expansion constraint thickness t3 is performed during charging and discharging of the secondary battery cell 10 according to the measurement conditions set by the operator and / or the temperature of the secondary battery cell 10 depends on the condition set by the operator. It can be repeated continuously or intermittently while being adjusted accordingly.

Preferably, in the state (c) of FIG. 2, the control unit 60 may control to change (increase) the pressing force by driving the motor 46 so that the t3 value calculated in real time is maintained to be substantially the same as t1. . When t3 is adjusted to be equal to t1, the secondary battery cell 10 can be simulated experimentally in a state in which the secondary battery cell 10 is in a state in which it cannot be expanded due to the rigidity of the cartridge frame and the outer case.

In this operation example, the controller 60 may determine the magnitude of the pressing force from L3 calculated in real time using the measuring means 51, and the determined magnitude of the pressing force may be accumulated and stored in the memory 62 together with time information. . The controller 60 may display the change data of the pressing force or the thickness change data of the secondary battery cell 10 stored in the memory 62 on the display 100 when requested by the operator. The operator can then use the change data of the pressing force to determine the strength data necessary for the design of the cartridge frame or the outer case of the modular battery. In addition, the controller 60 maintains the progress of the charge / discharge cycle or the high temperature state of the secondary battery cell 10 until the secondary battery cell 10 ruptures, and the memory (until the secondary battery cell 10 ruptures). The change data of the pressing force or the thickness change data of the secondary battery cell 10 stored in 62 may be displayed on the display 100. Then, the operator may utilize the displayed pressure change data and thickness change data in the design of the secondary battery cell 10.

On the other hand, in FIG. 2 (b) and (c), although the cell thickness measurement in the case where the pressing force changes in the direction of increase (L1 <L2 <3) was demonstrated, pressing force can be kept constant during cell thickness measurement. In this case, the controller 60 may raise the driving block 42 so that the pressing force is kept constant (L1 = L2) as the cell thickness increases. In addition, the controller 60 continuously or intermittently determines the thickness of the secondary battery cell 10 using the measuring means 51 and 52 while the pressing force is kept constant, and the determined thickness of the memory 62 together with time information. Can be stored in In addition, the controller 60 may display the thickness change data or the pressure change data of the secondary battery cell 10 stored in the memory 62 on the display 100 when requested by an operator. Then, the operator can observe the cell thickness change and behavior during use or storage of the secondary battery cell in a state in which the pressing force applied to the secondary battery cell 10 is constant.

As described above, the conventional technology merely measures the thickness of the cell once under a fixed condition (fixed pressing force), whereas in the present invention, each secondary battery cell of the modular battery in a desired pressing force (for example, an initial state of the secondary battery) is used. The applied pressure applied to the secondary battery cell when the secondary battery cell expands while the secondary battery performs the charge / discharge cycle, and the applied pressure applied to the secondary battery cell when the secondary battery is left at high or low temperatures for a long time. Various and easy to set up and measure. Therefore, the thickness change and the behavior of the secondary battery cell can be observed under conditions near the time of actual use or storage. Further, by controlling the pressing force to suppress the change in the thickness of the secondary battery cell, the behavior of the secondary battery cell in actual use or storage can be observed. The thickness change data or the pressure change data of the secondary battery cell 10 stored in the memory 62 may be used to determine physical strength data required for a cartridge frame, an external case, or a pouch.

In describing the various embodiments of the present invention, elements designated as 'parts' should be understood to be functionally divided elements rather than physically separated elements. Thus, each component may be selectively integrated with other components or each component may be divided into subcomponents for efficient execution of control logic (s). However, it will be apparent to those skilled in the art that the integrated or divided components should also be interpreted as being within the scope of the present invention, provided that the functional identity can be recognized even if the components are integrated or divided.

As mentioned above, although the preferred embodiment of the present invention has been illustrated and described, the present invention is not limited to the specific preferred embodiment described above, and the present invention belongs to the present invention without departing from the gist of the present invention as claimed in the claims. Various modifications can be made by those skilled in the art, and such changes are within the scope of the claims.

In the present invention, the thickness of the cell can be measured by variously and easily setting the desired pressing force or ambient temperature. Therefore, the thickness change and behavior of the secondary battery cell can be observed under conditions close to the time of actual use or storage, and further, the thickness change of the secondary battery cell can be suppressed and the behavior of the secondary battery cell during use or storage can be suppressed. The physical strength data required for the cartridge frame, the outer case and the pouch can be obtained.

Claims (17)

A mounting table on which a secondary battery cell to measure thickness is placed; A pressure plate facing the mounting table with the secondary battery cell interposed therebetween, and having a variable distance from the mounting table; Pressing means for pressing the secondary battery cell placed on the mounting table in a thickness direction by pushing or pulling the pressing plate toward the mounting table; Measuring means for measuring a pressing force applied to the pressing plate at a time interval and a thickness of the secondary battery cell; And The charging, discharging, or temperature of the secondary battery cell is controlled according to the measurement conditions input by the operator, and the magnitude of the pressing force applied to the pressure plate and the pressing force measurement value and the thickness measurement value are input from the measuring means at intervals. A control unit configured to determine a thickness of the secondary battery cell and store the same in time in the memory together with the time information, and to maintain or change a pressing force applied to the pressure plate by the pressing unit while the thickness of the secondary battery cell is measured. Thickness measuring device of a secondary battery cell, characterized in that. The method of claim 1, wherein the pressing means, An elastic member installed on opposite surfaces of the surface of the pressure plate in contact with the secondary battery cell to elastically bias the pressure plate; A driving block coupled with the elastic member to push or pull the elastic member along a thickness direction of the secondary battery cell; And And a driving unit that raises or lowers the driving block along the thickness direction of the secondary battery cell. The method of claim 2, The measuring means measures the distance between the drive block and the pressure plate at a time interval and outputs the distance measurement value as a pressing force measurement value, The control unit receives the distance measurement value from the measuring means to determine the length of the elastic member, determine the magnitude of the pressing force applied to the pressing plate by the determined length of the elastic member, and determine the magnitude of the determined pressing force by time information. Thickness measuring device of a secondary battery cell, characterized in that configured to be stored in the memory with. The method of claim 3, The control unit is a thickness measuring device of the secondary battery cell, characterized in that configured to display the change data of the pressing force or the change data of the thickness of the secondary battery cell stored in the memory. The method of claim 3, The controller determines the thickness of the secondary battery cell by using the length of the elastic member, the moving distance of the driving block, and the initial distance between the mounting table and the pressure plate, and stores the determined thickness in the memory together with time information. Thickness measuring device of a secondary battery cell, characterized in that configured to. The method of claim 5, The control unit is a thickness measuring device of the secondary battery cell, characterized in that configured to display the change data of the thickness of the secondary battery cell or the change of the pressure force stored in the memory on the display. The method of claim 1, The measuring means includes a piezoelectric sensor disposed between the surface of the mounting table and the surface of the pressure plate that faces the surface of the mounting table, and outputs a thickness measurement value of the secondary battery cell. Thickness measuring device. The method of claim 3, The measuring means is a distance measuring sensor for outputting a distance measurement value indicating the distance between the drive block and the pressure plate by measuring the time it takes to reciprocate between the drive block and the pressure plate by irradiating an optical signal, ultrasonic waves or infrared rays from the drive block or pressure plate Thickness measuring device of a secondary battery cell, characterized in that it comprises a. The method of claim 1, Further comprising a charge and discharge unit for charging or discharging the secondary battery cell, The controller receives a charge and discharge condition from an operator and stores it in a memory, and controls the charge and discharge unit according to the charge and discharge condition to charge and discharge the secondary battery cell. . The method of claim 1, Further comprising a heater installed on at least one of the pressure plate and the mounting table, The control unit is configured to receive a heating temperature set value from an operator, store in a memory, and control the temperature of the heater according to the heating temperature set value. The method of claim 1, Further comprising cooling means for cooling at least one of the pressure plate and the mounting table, The control unit receives a cooling temperature set value from an operator, stores in a memory, and controls the cooling means according to the cooling temperature set value, characterized in that the secondary battery cell thickness measuring apparatus. A mount on which a secondary battery cell to measure thickness is placed; A pressure plate elastically biased by an elastic member and having a variable distance from the mounting table with the secondary battery cell interposed therebetween; A driving block for pressing the secondary battery cell placed on the mounting table in a thickness direction by pushing or pulling the pressing plate toward the mounting table through the elastic member; In the method for measuring the thickness of the secondary battery cell by using the measuring means for measuring the pressing force applied to the pressure plate and the thickness of the secondary battery cell, (a) charging or discharging the secondary battery cell or adjusting a temperature of the secondary battery cell according to measurement conditions input by an operator; (b) receiving a pressing force measurement value and a thickness measurement value from the measuring means at time intervals to determine the magnitude of the pressing force applied to the pressure plate and the thickness of the secondary battery cell, and determine the magnitude and thickness of the pressing force; Storing in memory with; And (c) maintaining or changing a pressing force applied to the pressing plate by the pressing means while the thickness of the secondary battery cell is measured; and measuring the thickness of the secondary battery cell. The method of claim 12, Receiving a distance measurement value as a pressing force measurement value at a time interval from the measuring means; Determining a length of the elastic member from the distance measurement value; Determining the magnitude of the pressing force applied to the pressing plate by the length of the elastic member; Storing the determined pressing force together with time information in a memory; And And displaying the stored change data of the pressing force on a display. The method of claim 13, Determining the thickness of the secondary battery cell by using the length of the elastic member, the moving distance of the driving block, and the initial distance between the mounting table and the pressure plate, and storing the determined thickness with time information in a memory; And And displaying change data of the thickness of the secondary battery cells stored in the memory on a display. The method of claim 12, Receiving a charge / discharge condition from an operator; Charging and discharging the secondary battery cell according to the charge / discharge conditions while the thickness of the secondary battery cell is measured; And And displaying the change data of the thickness of the secondary battery cell according to the size of the pressing force or the change data of the pressing force according to the thickness of the secondary battery cell on a display. The method of claim 12, Receiving a heating temperature set value from an operator; Heating the secondary battery cell such that the temperature of the secondary battery cell corresponds to the heating temperature setting value using a heater installed on at least one of the pressure plate and the mounting table while the thickness of the secondary battery cell is measured; And And displaying the change data of the thickness of the secondary battery cell according to the size of the pressing force or the change data of the pressing force according to the thickness of the secondary battery cell on a display. The method of claim 12, Receiving a cooling temperature set value from an operator; Cooling the secondary battery cell such that the temperature of the secondary battery cell corresponds to the cooling temperature setting value by using cooling means installed on at least one of the pressure plate and the mounting table while the thickness of the secondary battery cell is measured; And And displaying the change data of the thickness of the secondary battery cell according to the size of the pressing force or the change data of the pressing force according to the thickness of the secondary battery cell on a display.

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