JP7674085B2 - Sealing member, electrode, lead-acid battery, battery pack and electric vehicle - Google Patents

Description

One aspect of the present invention relates to a sealing member, an electrode, a lead-acid battery, a battery pack, and an electric vehicle.

Lead-acid batteries are widely used as secondary batteries for industrial and consumer use, and there is particularly high demand for them as lead-acid batteries (so-called batteries) for electric vehicles, or as backup lead-acid batteries for UPS (Uninterruptible Power Supply), disaster prevention (emergency) radios, telephones, etc.

The lead-acid battery comprises an electrode group including a plurality of electrodes, and a battery case that houses the electrode group. The electrodes include, for example, a plurality of cylindrical bodies, a plurality of rod-shaped current collectors inserted into each of the plurality of cylindrical bodies, and an electrode material including an active material that is filled inside each of the plurality of cylindrical bodies. In such an electrode, the ends of the plurality of cylindrical bodies are sealed by a sealing member (lower connecting seat), as described in Patent Document 1, for example.

Japanese Patent Application Laid-Open No. 61-232572

In the above-mentioned conventional technology, when the electrode group is inserted into the battery case, the electrode group may come into contact with the battery case, and in particular, the sealing member of the electrode group's electrodes may come into contact with the battery case. In this case, the sealing member may be damaged, which may cause the lead-acid battery to malfunction.

One aspect of the present invention aims to provide a sealing member, an electrode, a lead-acid battery, a battery pack, and an electric vehicle that can suppress damage.

A sealing member according to one aspect of the present invention is a sealing member for sealing the ends of a plurality of cylindrical bodies in an electrode having a plurality of cylindrical bodies aligned along a first direction, in which, when viewed from a second direction intersecting the first direction and intersecting the axial direction of the cylindrical bodies, the edges of one end side and the other end side in the first direction on the bottom side, which is opposite to the side of the sealing member that is inserted into the cylindrical bodies, are chamfered, and when viewed from the first direction, the edges of one end side and the other end side in the second direction on the bottom side of the sealing member are chamfered, and the sealing member is aligned along the first direction and a portion is inserted into each of the plurality of cylindrical bodies. The sealing member has a plurality of body parts that are connected to each other and a connecting part that connects the plurality of body parts to each other, and the bottom side of the body parts arranged at least at one end side and the other end side in the first direction among the plurality of body parts forms a truncated cone shape or a truncated sphere shape that tapers toward the bottom side, and when viewed from the second direction, the edges of the one end side and the other end side in the first direction on the bottom side of the sealing member are inclined or curved following the truncated cone shape or the truncated sphere shape of the body part, and when viewed from the first direction, the edges of the one end side and the other end side in the second direction on the bottom side of the sealing member are inclined or curved following the truncated cone shape or the truncated sphere shape of the body part.

When an electrode group including a plurality of electrodes is inserted into a battery case, it is found that the one end side and the other end side of the sealing member of the electrodes in the first direction (the direction in which the plurality of cylindrical bodies are arranged) are likely to hit. In this regard, in the sealing member according to one aspect of the present invention, when viewed from the second direction, the edges of the one end side and the other end side of the bottom side of the sealing member in the first direction are chamfered. When viewed from the first direction, the edges of the one end side and the other end side of the bottom side of the sealing member in the second direction are chamfered. With this configuration, when the electrode group is inserted into the battery case from the bottom side of the sealing member, even if the one end side and the other end side of the sealing member in the first direction hits the battery case, the force is easily deflected along the chamfer. Therefore, it is possible to suppress damage to the sealing member. In particular, the edge is inclined or curved following the cone frustum or spherical frustum shape of the main body, and with this configuration, even if the one end side and the other end side of the sealing member in the first direction hits the battery case, the effect of deflecting the force is remarkable. It is possible to further suppress damage to the sealing member.

In a sealing member according to one aspect of the present invention, at least a portion of the main body portion located at one end side and/or the other end side in the first direction may be formed larger than the other main body portions. This can increase the durability of the sealing member, for example.

In the sealing member according to one aspect of the present invention, the bottom sides of all of the multiple main body parts may be frustum-shaped or frustum-shaped. With this configuration, when the electrode group is inserted into the battery case from the bottom side of the sealing member, even if the electrode group hits the battery case, the force can be deflected along the frustum-shaped or frustum-shaped portion of the bottom side of the entire sealing member. This makes it possible to further suppress damage to the sealing member. In addition, it becomes easier to insert the electrode group into the battery case from the bottom side of the sealing member.

A sealing member according to one aspect of the present invention is a sealing member for sealing the ends of a plurality of cylindrical bodies in an electrode having a plurality of cylindrical bodies aligned along a first direction, and when viewed from a second direction intersecting the first direction and intersecting the axial direction of the cylindrical bodies, the edges of one end side and the other end side of the bottom side of the sealing member in the first direction, which is opposite to the side of the sealing member inserted into the cylindrical bodies, are chamfered, and when viewed from the first direction, the edges of one end side and the other end side of the bottom side of the sealing member in the second direction are chamfered, and the sealing member is provided with a plurality of main body parts aligned along the first direction, a portion of which is inserted into each of the plurality of cylindrical bodies, and a connecting portion connecting the plurality of main body parts to each other, and at least a portion of the main body parts located at the one end side and/or the other end side in the first direction is formed larger than the other main body parts.

In this sealing member, when viewed from the second direction, the edges of one end side and the other end side of the bottom side of the sealing member in the first direction are chamfered. When viewed from the first direction, the edges of one end side and the other end side of the bottom side of the sealing member in the second direction are chamfered. With this configuration, when the electrode group is inserted into the battery case from the bottom side of the sealing member, even if the one end side and the other end side of the sealing member in the first direction hit the battery case, the force is easily deflected along the chamfer. Therefore, it is possible to suppress damage to the sealing member. In addition, at least a part of the main body portion located at the one end side and/or the other end side in the first direction is formed large. This can increase the durability of the sealing member, for example.

In the sealing member according to one aspect of the present invention, the bottom side of the sealing member may be provided with a contact surface along a plane intersecting the axial direction, which contacts a plurality of ridges provided on the bottom surface of the battery case that contains the electrodes. As a result, even if the position where the sealing member contacts the ridges shifts, the contact surface provides a uniform force to support the sealing member and, in turn, the electrodes.

An electrode according to one aspect of the present invention comprises a plurality of cylindrical bodies arranged along a first direction, a plurality of rod-shaped current collectors inserted into each of the plurality of cylindrical bodies, an electrode material containing an active material filled inside each of the plurality of cylindrical bodies, and the sealing member. This electrode also comprises the sealing member, making it possible to suppress damage.

A lead-acid battery according to one aspect of the present invention includes the above-described electrodes. This battery also includes the above-described sealing member, making it possible to suppress damage.

A battery pack according to one aspect of the present invention includes the lead-acid battery and a connection member that electrically connects one lead-acid battery to another lead-acid battery. This battery pack also includes the sealing member, which makes it possible to suppress damage.

An electric vehicle according to one aspect of the present invention includes the lead-acid battery. This electric vehicle also includes the sealing member, which makes it possible to suppress damage.

According to one aspect of the present invention, it is possible to provide a sealing member, an electrode, a lead-acid battery, a battery pack, and an electric vehicle that can suppress damage.

FIG. 1 is a cross-sectional view that illustrates a lead-acid battery according to an embodiment. FIG. 2 is a partial cross-sectional view taken along line II-II in FIG. FIG. 3 is a perspective view showing the positive electrode of FIG. FIG. 4 is a front view showing the lower linkage of FIG. FIG. 5 is a rear view showing the lower linkage of FIG. FIG. 6 is a plan view showing the lower linkage of FIG. FIG. 7 is a bottom view showing the lower linkage of FIG. FIG. 8 is a left side view showing the lower linkage of FIG. 9 is a right side view showing the lower linkage of FIG. 1. FIG. 10 is a perspective view of the lower link seat of FIG. 1 as viewed from the protruding piece side. FIG. 11 is a perspective view of the lower link seat of FIG. 1 as viewed from the contact surface side. FIG. 12 is a cross-sectional view taken along line AA of FIG. FIG. 13 is an end view taken along line BB of FIG. FIG. 14 is a front view showing a part of the lower linking seat according to the modified example. FIG. 15 is a left side view showing a lower link seat according to a modified example. FIG. 16 is a left side view showing a lower link seat according to another modified example.

Embodiments of the present invention will be described in detail below with reference to the drawings. In the drawings, identical or equivalent elements are given the same reference numerals, and duplicate explanations will be omitted. The sizes of the components in each drawing are conceptual, and the relative relationships of the sizes between the components are not limited to those shown in each drawing.

Figure 1 is a cross-sectional view showing a schematic diagram of a lead-acid battery. Figure 2 is a partial cross-sectional view taken along line II-II in Figure 1. Figure 3 is a perspective view showing a positive electrode. In Figure 1, positive electrodes and negative electrodes are alternately arranged with separators between them from the front to the back of the drawing. Figure 1 shows a cross-sectional view of a portion of the positive electrode. Figure 2 shows the laminated structure of the positive electrode, negative electrode, and separator when the lead-acid battery is viewed from above. The terms "upper" and "lower" correspond to the upper and lower sides in the height direction of the battery case (the same applies below). The Z direction corresponds to the height direction of the battery case, the X direction corresponds to the direction perpendicular to the Z direction, and the Y direction corresponds to the direction perpendicular to both the Z direction and the X direction.

As shown in Figs. 1 and 2, the lead-acid battery 100 according to the embodiment includes an electrode group 110, a battery case 120 that houses the electrode group 110, connecting members 130a and 130b connected to the electrode group 110, poles 140a and 140b connected to the connecting members 130a and 130b, a liquid port plug 150 that closes the liquid inlet of the battery case 120, and a support member 160 connected to the battery case 120.

The electrode group 110 includes a plurality of positive electrodes 10, a plurality of negative electrodes 20, and a plurality of separators 30. The positive electrodes 10 and the negative electrodes 20 are alternately arranged in the X direction with the separators 30 interposed therebetween. The space around the positive electrodes 10 between the separators 30 is filled with an electrolyte 40. There are no particular limitations on the material of the separator 30, so long as it prevents electrical connection between the positive electrodes 10 and the negative electrodes 20 and allows the electrolyte 40 to pass through. Examples of materials for the separator 30 include a mixture of microporous polyethylene, glass fiber, and synthetic resin.

As shown in Figures 1, 2, and 3, the positive electrode 10 is, for example, a plate-shaped electrode. The positive electrode 10 has a plurality of cylindrical bodies 12a, a plurality of core metals (current collectors) 14, a positive electrode material (electrode material) 16, a lower connecting seat (sealing member) 1, an upper connecting seat 12c, and an ear portion 12d.

The multiple cylindrical bodies 12a are arranged adjacent to each other in a row along the Y direction, which is a first direction perpendicular to the axial direction of the cylindrical bodies 12a (hereinafter also simply referred to as the "axial direction"). The multiple cylindrical bodies 12a constitute a group of tubes (clad tubes) for holding active material. The cylindrical bodies 12a extend in the Z direction. The structure in which the multiple cylindrical bodies 12a are arranged side by side may be obtained by the cylindrical bodies 12a being separate from each other, or may be obtained by forming multiple through holes between the substrates facing each other. A connection part such as a seam (seamed part) may be arranged between the adjacent cylindrical bodies 12a.

The outer shape of the cross section of the cylindrical body 12a perpendicular to the Z direction may be a circle, an ellipse, a rounded rectangle, or the like. The length of the cylindrical body 12a is, for example, 160 to 400 mm. The diameter of the cylindrical body 12a may be, for example, 5 mm or more. The diameter of the cylindrical body 12a may be, for example, 12 mm or less. The thickness of the cylindrical body 12a may be, for example, 100 μm or more. The thickness of the cylindrical body 12a may be, for example, 2000 μm or less. When the outer shape of the cross section of the cylindrical body 12a is non-circular, the diameter of the cylindrical body 12a may be, for example, the diameter of an inscribed circle inscribed in the outer edge of the cross section.

The cylindrical body 12a is formed of a porous body. The cylindrical body 12a may be formed of a base material such as a woven fabric or a nonwoven fabric. An acid-resistant material can be used as the base material. Examples of the base material include resins such as polyolefin (polypropylene, polyethylene, etc.), polyethylene terephthalate (PET), polystyrene (PS), polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), polyvinylidene fluoride (PVDF), and polycarbonate (PC), and inorganic materials such as glass fiber, silicon carbide, and alumina. From the viewpoint of easily improving cycle characteristics, the cylindrical body 12a preferably contains a thermoplastic resin, and more preferably contains a polyolefin.

In the cylindrical body 12a, a resin may be held on the substrate. Examples of the resin include acrylic resin, epoxy resin, phenolic resin, melamine resin, and styrene resin. The resin may be held on the inner or outer surface of the substrate, or on the surface inside the pores in the substrate, or may be attached to the substrate. The resin may be held on a part of the substrate, or on the entire substrate.

The core metal 14 is inserted into each cylindrical body 12a. The core metal 14 is rod-shaped. The core metal 14 extends along the Z direction inside the cylindrical body 12a. The core metal 14 can be obtained, for example, by casting (pressure casting). The constituent material of the core metal 14 may be any conductive material, such as a lead alloy such as a lead-calcium-tin alloy or a lead-antimony-arsenic alloy. The lead alloy may contain selenium, silver, bismuth, etc. The outer shape of the cross section of the core metal 14 perpendicular to the Z direction may be a circle, an ellipse, etc. The length of the core metal 14 is, for example, 170 to 400 mm. The diameter of the core metal 14 is, for example, 2.0 to 4.0 mm.

The positive electrode material 16 is filled inside the cylindrical body 12a. The positive electrode material 16 includes an active material. The active material includes both the active material after chemical conversion and the raw material of the active material before chemical conversion. The positive electrode material 16 here contains the active material after chemical conversion. The positive electrode material 16 after chemical conversion can be obtained, for example, by chemical conversion of the unchemical positive electrode material 16 containing the raw material of the positive electrode active material. The positive electrode material 16 after chemical conversion can be obtained, for example, by aging and drying a positive electrode material paste containing the raw material of the positive electrode active material to obtain the unchemical positive electrode material 16, and then chemical conversion of the unchemical positive electrode material 16. Examples of the raw material of the positive electrode active material include lead powder and red lead. Examples of the positive electrode active material in the positive electrode material 16 after chemical conversion include lead dioxide. The positive electrode material 16 may further contain an additive as necessary. Examples of the additive of the positive electrode material 16 include short fibers for reinforcement. Examples of reinforcing short fibers include acrylic fibers, polyethylene fibers, polypropylene fibers, and polyethylene terephthalate fibers (PET fibers).

The cylindrical body 12a, the metal core 14, and the positive electrode material 16 constitute a cylindrical electrode (rod-shaped electrode). The cylindrical electrode of the positive electrode 10 is electrically connected to the pole 140a via the upper seat 12c, the ear 12d, and the connecting member 130a.

The lower linking seat 1 is attached to the lower end of the multiple cylindrical bodies 12a, which is the end on the bottom side of the battery case 120 (the end portion on one end side of the cylindrical body 12a). The lower linking seat 1 seals the lower end of the multiple cylindrical bodies 12a. The lower linking seat 1 is fitted into the lower end of the multiple cylindrical bodies 12a. The lower linking seat 1 may be fixed to the lower end of the multiple cylindrical bodies 12a with a thermosetting adhesive or the like.

The material of the lower linking seat 1 may be an acid-resistant material. Examples of the material of the lower linking seat 1 include resins such as polyolefin (polypropylene, polyethylene, etc.), polyethylene terephthalate (PET), polystyrene (PS), polyvinylidene fluoride (PVDF), and polycarbonate (PC). From the viewpoint of easily improving cycle characteristics, the lower linking seat 1 preferably contains a thermoplastic resin, more preferably contains a polyolefin, and even more preferably contains polypropylene. From the viewpoint of easily improving cycle characteristics, when the cylindrical body 12a contains a polyolefin, the lower linking seat 1 preferably contains these materials. The lower linking seat 1 may be formed of the same material as the cylindrical body 12a, or may be formed of a material different from that of the cylindrical body 12a.

The upper linking seat 12c is attached to the upper end of the cylindrical body 12a, which is the end on the top side of the battery case 120 (the end portion on the other end side of the cylindrical body 12a). The upper linking seat 12c seals the upper end of the cylindrical body 12a. The upper linking seat 12c is fixed to the upper end of the cylindrical body 12a by welding. In welding, the boundary portion between the upper linking seat 12c and the cylindrical body 12a and the upper linking seat 12c may be integrated. Welding can be achieved by heating, ultrasonic irradiation, laser irradiation, etc. The upper linking seat 12c may be fixed to the upper ends of multiple cylindrical bodies 12a by a thermosetting adhesive or the like.

The lower linking seat 1 and the upper linking seat 12c contact the cylindrical body 12a and the core metal 14 and the positive electrode material 16 arranged inside the cylindrical body 12a. The lower linking seat 1 and the upper linking seat 12c hold the cylindrical body 12a, the core metal 14, and the positive electrode material 16. One end of the ear portion 12d is connected to the upper linking seat 12c. The other end of the ear portion 12d is connected to the connecting member 130a.

1 and 2, the negative electrode 20 is, for example, a plate-shaped electrode. The negative electrode 20 is, for example, a paste-type negative electrode plate. The negative electrode 20 is electrically connected to the electrode column 140b via a connecting member 130b. The negative electrode 20 has a negative electrode collector and a negative electrode material that is an electrode material held by the negative electrode collector. A plate-shaped collector can be used as the negative electrode collector. The compositions of the negative electrode collector and the core metal 14 of the positive electrode 10 may be the same or different. The negative electrode material contains an active material. The negative electrode material here contains the active material after chemical formation.

The negative electrode material after chemical formation can be obtained, for example, by chemically forming an unformed negative electrode material containing the raw material of the negative electrode active material. The negative electrode material after chemical formation can be obtained, for example, by aging and drying a negative electrode material paste containing the raw material of the negative electrode active material to obtain an unformed negative electrode material, and then chemically forming the unformed negative electrode material. Examples of raw materials for the negative electrode active material include lead powder. Examples of negative electrode active materials in the negative electrode material after chemical formation include porous spongy lead. The negative electrode material can further contain additives as necessary. Examples of additives for the negative electrode material include barium sulfate, reinforcing short fibers, carbon materials (carbonaceous conductive materials), resins having at least one selected from the group consisting of sulfonic groups and sulfonic acid salt groups (resins having sulfonic groups and/or sulfonic acid salt groups), and the like. As the reinforcing short fibers, reinforcing short fibers similar to those used in the positive electrode material can be used.

Examples of carbon materials include carbon black and graphite. Examples of carbon black include furnace black (Ketjen Black (registered trademark), etc.), channel black, acetylene black, and thermal black. Examples of resins having a sulfonic group and/or a sulfonate group include lignin sulfonic acid, lignin sulfonate salts, and condensates of phenols, aminoarylsulfonic acid, and formaldehyde. Examples of lignin sulfonate salts include alkali metal salts of lignin sulfonic acid. Examples of phenols include bisphenol-based compounds such as bisphenol. Examples of aminoarylsulfonic acids include aminobenzenesulfonic acid and aminonaphthalenesulfonic acid.

The support member 160 is disposed on the bottom surface of the battery case 120 and supports the lower linking seat 1. The support member 160 has a number of ridges 160a that protrude in the Z direction. The ridges 160a are provided on the support member 160. In other words, the ridges 160a are provided on the bottom surface of the battery case 120 (at a position above the bottom surface). The ridges 160a extend in the X direction as the second direction. The ridges 160a are aligned in the Y direction. The ridges 160a abut against the lower linking seat 1 (see FIG. 1). That is, the support member 160 supports the bottom side portion of the battery case 120 in the lower linking seat 1 with the ridges 160a. The ridges 160a only need to be in contact with the positive electrode 10, and do not need to be in contact with the negative electrode 20.

Next, we will explain the lower link 1 in detail.

Figure 4 is a front view of the lower linking seat 1. Figure 5 is a rear view of the lower linking seat 1. Figure 6 is a plan view of the lower linking seat 1. Figure 7 is a bottom view of the lower linking seat 1. Figure 8 is a left side view of the lower linking seat 1. Figure 9 is a right side view of the lower linking seat 1. Figure 10 is a perspective view of the lower linking seat 1 from the protruding piece 3 side. Figure 11 is a perspective view of the lower linking seat 1 from the contact surface 6 side. Figure 12 is a cross-sectional view taken along line A-A in Figure 4. Figure 13 is an end view taken along line B-B in Figure 6.

The lower linking seat 1 is a member that seals the ends of the multiple cylindrical bodies 12a that are lined up along the Y direction. The lower linking seat 1 fits onto the ends of the multiple cylindrical bodies 12a. As shown in at least one of Figures 4 to 13, the lower linking seat 1 includes multiple main body parts 2, protruding pieces 3 provided on each of the multiple main body parts 2, and connecting parts 4 that connect the multiple main body parts 2.

The main body 2 is partially inserted into and fitted to the lower end of the cylindrical body 12a. The main body 2 has a bottomed cylindrical shape that opens upward. The end of the core 14 is inserted into and fitted to the cylindrical hole 2h of the main body 2. This holds the core 14 in the cylindrical hole 2h. A plurality of main bodies 2 are provided corresponding to the plurality of cylindrical bodies 12a. The plurality of main bodies 2 are arranged in parallel with a predetermined gap in the Y direction. The main body 2 includes a small diameter portion 2x located on the upper side and a large diameter portion 2y located below and having a larger diameter than the small diameter portion 2x. The side of the main body 2 that is inserted into the cylindrical body 12a is the upper side, and the opposite side is the lower side (also called the bottom side).

The small diameter portion 2x is the portion on the opening side of the main body 2, and is the first portion that is fitted into the lower end of the cylindrical body 12a. The upper portion (the end on the opening side) of the small diameter portion 2x forms a pointed portion that is pointed upward. In other words, the outer peripheral surface of the upper portion of the small diameter portion 2x has an inclined surface that slopes radially inward as it progresses upward. The inner peripheral surface of the upper portion of the small diameter portion 2x has an inclined surface that slopes radially outward as it progresses upward. The tip of the upper portion of the small diameter portion 2x is rounded and chamfered.

The large diameter portion 2y is the portion that abuts against the lower end surface of the cylindrical body 12a, and is the second portion that is located below the cylindrical body 12a when the small diameter portion 2x is fitted into the cylindrical body 12a. The lower portion of the large diameter portion 2y forms a truncated cone shape that tapers downward. In other words, the lower side of the main body portion 2 forms a truncated cone shape that tapers downward. The large diameter portion 2y has an inclined surface 7 on the outer peripheral surface of its lower portion that slopes radially inward as it progresses downward.

Four protruding pieces 3 are provided on each main body 2 so as to protrude along the Z direction. When viewed from above, the protruding pieces 3 are provided at four equally spaced positions (four equally spaced locations) around the axial direction of the small diameter portion 2x of each main body 2. The protruding pieces 3 are plate-shaped extending along the radial direction of the main body 2 and along the Z direction. The protruding pieces 3 are disposed inside the cylindrical body 12a. The upper portions of the protruding pieces 3 form a pointed portion that points upward. The tips of the upper portions of the protruding pieces 3 are rounded.

The connecting parts 4 connect the multiple main body parts 2 in a parallel state with a predetermined gap in the Y direction. The connecting parts 4 connect the large diameter parts 2y of adjacent main body parts 2. The connecting parts 4 extend along the Y direction. The connecting parts 4 are provided so as to be integral (inseparably intertwined) with the main body parts 2.

In this embodiment, as shown in FIG. 4 and FIG. 5, when viewed from the X direction, the edges E1 on one end side and the other end side in the Y direction on the lower side (bottom side) of the lower link 1 are inclined so as to incline inward in the Y direction as they go downward. In other words, when viewed from the X direction, the lower side and both ends in the Y direction of the lower link 1 are configured so that their corners are notched. Specifically, when viewed from the X direction, the edges E1 on one end side and the other end side in the Y direction on the lower side of the lower link 1 are inclined following the frustum shape of the main body 2. More specifically, when viewed from the X direction, the edges E1 on both ends in the Y direction on the lower side of the lower link 1 are inclined following the inclined surface 7 formed on the outer peripheral surface of the lower part of the large diameter part 2y of the main body 2. When viewed from the X direction, the edges E1 on one end side and the other end side in the Y direction on the lower side of the lower link 1 are chamfered. For example, the chamfering is configured so that the corners are notched. For example, chamfering is a shape that is obtained by removing the corners where surfaces meet. Chamfering includes various types of chamfering, such as corner chamfering and round chamfering, and here, it is corner chamfering. There are no particular limitations on the manufacturing method for achieving chamfering. Chamfering may be achieved by molding, grinding or cutting, polishing, or a combination of these.

8 and 9, in this embodiment, as viewed from the Y direction, the edges E2 on one end side and the other end side in the X direction on the lower side (bottom side) of the lower link seat 1 are inclined so as to incline inward in the X direction as they go downward. In other words, as viewed from the Y direction, the corners of the lower side and both ends in the X direction of the lower side of the lower link seat 1 are configured so that they are notched. Specifically, as viewed from the Y direction, the edges E2 on one end side and the other end side in the X direction on the lower side of the lower link seat 1 are inclined following the frustum shape of the main body 2. More specifically, as viewed from the Y direction, the edges E2 on both ends in the X direction on the lower side of the lower link seat 1 are inclined following the inclined surface 7 formed on the outer peripheral surface of the lower part of the large diameter part 2y of the main body 2. As viewed from the Y direction, the edges E2 on one end side and the other end side in the X direction on the lower side of the lower link seat 1 are chamfered.

In this embodiment, the lower side of the lower link 1 is provided with abutment surface 6 that is a surface along the XY plane (a plane intersecting the Z direction) and abuts against multiple protrusions 160a (see FIG. 1) of the support member 160. In other words, the lower surface (bottom surface) of the lower link 1 constitutes the abutment surface 6 as a plane along the XY plane. The lower surface of the lower link 1 includes the lower surface of the connecting portion 4 and the lower surface of the large diameter portion 2y. Note that the abutment surface 6 only needs to be along the XY plane, and may have a waviness of, for example, ±0.1 mm to ±3 mm.

Next, a method for manufacturing the lead-acid battery 100 will be described. The method for manufacturing the lead-acid battery 100 includes at least an electrode manufacturing process for manufacturing electrodes, and an assembly process for assembling each component to obtain the lead-acid battery 100.

In the electrode manufacturing process, for example, a positive electrode 10 having a cylindrical body 12a is obtained. The electrode manufacturing process includes a step of forming the cylindrical body 12a, a step of sealing the upper end of the cylindrical body 12a with an upper connecting seat 12c, a step of placing the core metal 14 and the positive electrode material 16 inside the cylindrical body 12a, and a step of sealing the lower end of the cylindrical body 12a with a lower connecting seat 1.

In the assembly process, for example, unformed positive electrodes 10 and unformed negative electrodes 20 are stacked via separators 30, and the current collectors of the electrodes of the same polarity are welded with straps to obtain an electrode group 110. The electrode group 110 is inserted and placed in a battery case 120 to produce an unformed battery. Dilute sulfuric acid is poured into the unformed battery and direct current is passed through it to form the battery case. The specific gravity of the sulfuric acid after formation is adjusted to an appropriate specific gravity to obtain a lead-acid battery 100. Note that the formation process is not limited to being performed after the assembly method, and may be performed during the electrode manufacturing method (tank formation).

By the way, when the electrode group 110 is inserted into the battery case 120, it is found that the one end side and the other end side of the lower link 1 of the positive electrode 10 in the Y direction (the direction in which the multiple cylindrical bodies 12a are arranged) are particularly likely to hit. In this regard, in the lower link 1, when viewed from the X direction, the edges E1 of the one end side and the other end side in the Y direction at the bottom side of the lower link 1 are inclined so as to tilt inward in the Y direction as they go downward. When viewed from the Y direction, the edges E2 of the one end side and the other end side in the X direction at the bottom side of the lower link 1 are inclined so as to tilt inward in the X direction as they go downward. With this configuration, when the electrode group 110 is inserted into the battery case 120 from the bottom side of the lower link 1, even if the one end side and the other end side of the lower link 1 in the Y direction hit the battery case 120, the force is easily deflected along the inclination. That is, the portions of the lower link 1 on one end side and the other end side in the Y direction are less likely to hit the battery case 120 strongly. This makes it possible to suppress damage to the lower link 1. In turn, it makes it possible to suppress damage to the positive electrode 10 or the electrode group 110. It makes it possible to suppress deformation defects when the electrode group 110 enters the battery case 120.

The lower linking seat 1 comprises a main body 2 and a connecting portion 4, and the lower side of the main body 2 forms a frustum shape. When viewed from the X direction, edges E1 on one and other ends in the Y direction of the bottom side of the lower linking seat 1 are inclined to imitate the frustum shape of the main body 2. When viewed from the Y direction, edges E2 on one and other ends in the X direction of the bottom side of the lower linking seat 1 are inclined to imitate the frustum shape of the main body 2. As a result, even if the one and other ends in the Y direction of the lower linking seat 1 hit the battery case 120, the force is deflected along the inclination, which is significant. This makes it possible to further suppress damage to the lower linking seat 1.

In the lower linking seat 1, the undersides of all of the multiple main body parts 2 form a frustum shape. With this configuration, when the electrode group 110 is inserted into the battery case 120 from the underside of the lower linking seat 1, even if the entire lower part of the lower linking seat 1 hits the battery case 120, the force can be deflected along the frustum shape. This makes it possible to further suppress damage to the lower linking seat 1. It also makes it easier to insert the electrode group 110 into the battery case 120 from the underside of the lower linking seat 1.

A support member 160 is disposed on the bottom surface of the battery case 120, and multiple protrusions 160a are provided on the support member 160. A contact surface 6 is provided on the underside of the lower link 1 along the XY plane, which contacts the multiple protrusions 160a. As a result, even if the position where the lower link 1 contacts the protrusions 160a shifts, the contact surface 6 ensures that the lower link 1 and thus the positive electrode 10 are supported with a uniform force.

The positive electrode 10 includes a plurality of cylindrical bodies 12a, a plurality of core metals 14 inserted into each of the plurality of cylindrical bodies 12a, a positive electrode material 16 filled inside each of the plurality of cylindrical bodies 12a, and a lower link 1. Even with such a positive electrode 10, it is possible to suppress damage to the lower link 1.

The lead-acid battery 100 includes a positive electrode 10. Even in such a lead-acid battery 100, it is possible to suppress damage to the lower link 1.

In the lower link 1, when viewed from the X direction, the edges E1 on one end side and the other end side in the Y direction on the bottom side of the lower link 1 are chamfered. When viewed from the Y direction, the edges E2 on one end side and the other end side in the X direction on the bottom side of the lower link 1 are chamfered. With this configuration, when the electrode group 110 is inserted into the battery case 120 from the bottom side of the lower link 1, even if the one end side and the other end side of the lower link 1 in the Y direction hit the battery case 120, the force is easily deflected along the chamfer. Therefore, it is possible to suppress damage to the lower link 1. In particular, the edges E1 and E2 are inclined following the cone frustum shape of the main body 2, and with this configuration, even if the one end side and the other end side of the lower link 1 in the Y direction hit the battery case 120, the effect of deflecting the force is remarkable. It is possible to further suppress damage to the lower link 1.

Although the embodiments have been described above, one aspect of the present invention is not limited to the above embodiments.

In one aspect of the present invention, the bottom side of the main body 2 forms a truncated cone shape, but is not limited to a truncated cone shape and may be another truncated cone shape, such as a truncated pyramid shape. In one aspect of the present invention, the bottom sides of all of the multiple main body parts 2 form a truncated cone shape, but it is sufficient that the bottom sides of at least the main body parts 2 arranged at one end side and the other end side in the Y direction among the multiple main body parts 2 form a truncated cone shape. For example, a truncated cone is a three-dimensional shape obtained by removing a portion of the apex side from a pyramid.

The positive electrode 10 and lead acid battery 100 equipped with the lower link 1 according to one aspect of the present invention can be used in electric vehicles. Examples of electric vehicles include forklifts and golf carts. In the present invention, the configurations of the above embodiment and the above modified examples may be appropriately combined. The present invention can be modified in various ways without departing from the spirit of the invention.

In one embodiment of the present invention, the lower linking seat 1 may be formed so that one end and/or the other end in the Y direction (the direction in which the multiple cylindrical bodies 12a are arranged) is larger than the remaining portions. For example, of the multiple main body parts 2 of the lower linking seat 1, the main body part 2 located at one end and/or the other end in the Y direction may be formed so that at least a portion of it is larger than the main body parts 2 located at one and the other ends in the Y direction. This can increase the durability of the lower linking seat 1, for example. It is possible to suppress damage to the lower linking seat 1.

This item is a cylindrical body sealant for electrodes of a lead-acid battery. In other words, this item is a sealant for sealing one end of multiple cylindrical bodies that make up the electrodes of a lead-acid battery. This item has a slope formed on the bottom side of the main body. As a result, when an electrode group including multiple electrodes to which this item is attached is inserted into a battery case, even if the item hits the battery case, the force can be deflected along the slope, and damage to the item can be suppressed.

14 is a front view showing a part of the lower link 1A according to the modified example. FIG. 15 is a left side view showing the lower link 1A according to the modified example. In the lower link 1A shown in FIG. 14 and FIG. 15, the main body 2 located at one end side and the other end side in the Y direction, which is the first direction, is formed at least partially larger than the other main body 2. Specifically, the large diameter portion 2y of the main body 2 located at one end side and the other end side in the Y direction is provided so as to bulge outward in the Y direction when viewed from the X direction compared to the other large diameter portions 2y (see FIG. 14). The large diameter portion 2y of the main body 2 located at one end side and the other end side in the Y direction is provided so as to bulge outward in the X direction when viewed from the Y direction compared to the other large diameter portions 2y (see FIG. 15). In other words, the main body 2 located at both ends in the Y direction is configured so that the large diameter portion 2y bulges outward compared to the main body 2 located between them.

In this type of lower link 1A, the main body 2 located at one end and the other end in the Y direction has a portion of the large diameter portion 2y formed larger than the other main body 2, so that, for example, the durability of the lower link 1A can be increased. It becomes possible to suppress damage to the lower link 1A.

In the lower linking seat 1A, it is sufficient that at least a portion of the main body 2 located at one end or the other end is formed larger than the remaining main body 2, rather than both one end and the other end. In the lower linking seat 1A, the portion of the main body 2 that is formed larger is not limited to the large diameter portion 2y, and other portions may be formed larger. It is sufficient that only a portion or the entire main body 2 at one end and/or the other end is formed larger than the remaining main body 2, and in short, it is sufficient that at least a portion of the main body 2 is formed larger.

Figure 16 is a left side view showing a lower linking seat 1B according to another modified example. In the lower linking seat 1B shown in Figure 16, the bottom side of at least the main body parts 2 arranged at one end side and the other end side in the Y direction among the multiple main body parts 2 forms a spherical trapezoid. When viewed from the X direction, the edges E3 on one end side and the other end side in the Y direction of the bottom side of the lower linking seat 1B are curved following the spherical trapezoid. When viewed from the Y direction, the edges E3 on one end side and the other end side in the X direction of the bottom side of the lower linking seat 1B are curved following the spherical trapezoid.

In such a lower linking seat 1B, the edge E3 is curved following the spherical trapezoid of the main body 2, so that even if the one end side and the other end side of the lower linking seat 1B in the Y direction hit the battery case 120, the force is deflected along the inclination, which is significant. This makes it possible to further suppress damage to the lower linking seat 1B. Note that the bottom side of only the main body 2 arranged on the one end side and the other end side may be spherical trapezoid, or the bottom side of all the main body parts 2 may be spherical trapezoid. For example, a spherical truncation is a three-dimensional shape obtained by cutting a sphere with two parallel planes. In other words, for example, a spherical truncation is a three-dimensional shape obtained by cutting a sphere with two parallel planes when the sphere intersects with these two planes and surrounded by the spherical portion (spherical zone) sandwiched between these two planes.

One aspect of the present invention may be a battery pack including a plurality of lead-acid batteries 100 and a connection member that electrically connects one lead-acid battery 100 to another lead-acid battery 100. This battery pack also includes a lower link seat 1, which makes it possible to suppress damage. One aspect of the present invention may be an electric vehicle including a lead-acid battery 100. This electric vehicle also includes a lower link seat 1, which makes it possible to suppress damage.

1, 1A, 1B...lower seat (sealing member), 2...main body, 4...connecting part, 6...contact surface, 10...positive electrode (electrode), 12a...cylindrical body, 14...core metal (current collector), 16...positive electrode material (electrode material), 100...lead-acid battery, 120...battery case, 160a...rib, E1...edge, E2...edge, E3...edge.

Claims (9)

In an electrode including a plurality of cylindrical bodies arranged along a first direction and a plurality of rod-shaped current collectors inserted into the plurality of cylindrical bodies, a sealing member that seals ends of the plurality of cylindrical bodies,
When viewed from a second direction intersecting the first direction and intersecting the axial direction of the cylindrical body, edges of one end side and the other end side in the first direction on a bottom side opposite to an upper side that is a side of the sealing member that is inserted into the cylindrical body are chamfered,
When viewed from the first direction, edges of one end side and the other end side of the bottom side of the sealing member in the second direction are chamfered,
A plurality of main body portions arranged along the first direction, portions of which are inserted into the respective cylindrical bodies;
A connecting portion that connects the plurality of main body portions to each other,
The bottom side of at least one of the plurality of main body portions arranged on one end side and the other end side in the first direction forms a truncated cone shape or a truncated spherical shape tapering toward the bottom side,
When viewed from the second direction, edges of one end side and the other end side of the bottom side of the sealing member in the first direction are inclined or curved following the frustum shape or the frustum of the main body portion,
When viewed from the first direction, edges of one end side and the other end side of the bottom side of the sealing member in the second direction are inclined or curved following the frustum shape or the frustum of the main body portion ,
The main body has a bottomed tubular shape that is open upward,
An end of the current collector is inserted and fitted into the cylindrical hole of the main body,
A sealing member, wherein the upper ends of the edges of one end side and the other end side in the first direction on the bottom side of the sealing member, and the upper ends of the edges of one end side and the other end side in the second direction on the bottom side of the sealing member are positioned above the bottom surface of the tubular hole of the main body portion . The sealing member according to claim 1, wherein at least a portion of the main body portion located at one end side and/or the other end side in the first direction is formed larger than the remaining main body portions. The sealing member according to claim 1 or 2, wherein the bottom sides of all of the plurality of body portions form the frustum shape or the frustum shape. A sealing member that seals ends of a plurality of cylindrical bodies in an electrode having a plurality of cylindrical bodies arranged along a first direction,
When viewed from a second direction intersecting the first direction and intersecting the axial direction of the cylindrical body, edges of one end side and the other end side in the first direction on a bottom side opposite to a side where the sealing member is inserted into the cylindrical body are chamfered,
When viewed from the first direction, edges of one end side and the other end side of the bottom side of the sealing member in the second direction are chamfered,
A plurality of main body portions arranged along the first direction, portions of which are inserted into the respective cylindrical bodies;
A connecting portion that connects the plurality of main body portions to each other,
A sealing member, wherein at least a portion of the main body portion located at one end side and/or the other end side in the first direction is formed larger than the other main body portions. The sealing member according to any one of claims 1 to 4, wherein the bottom side of the sealing member is provided with a contact surface along a plane intersecting the axial direction, the contact surface contacting a plurality of protrusions provided on the bottom surface of a battery case that contains the electrode. An electrode comprising: a plurality of cylindrical bodies arranged along a first direction; a plurality of rod-shaped current collectors inserted into each of the plurality of cylindrical bodies; an electrode material containing an active material filled inside each of the plurality of cylindrical bodies; and the sealing member according to any one of claims 1 to 5. A lead-acid battery comprising the electrode according to claim 6. A plurality of lead acid batteries according to claim 7;
a connection member that electrically connects one of the lead-acid batteries to another of the lead-acid batteries. An electric vehicle equipped with the lead-acid battery according to claim 7.

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