WO2020194684A1 - Battery module, battery pack, and vehicle - Google Patents

Abstract

According to an embodiment, a battery module comprises a battery array and a base plate, wherein the battery array includes a plurality of batteries. In an exterior part of each of the batteries, a first exterior member includes a bottom wall, a peripheral wall, and a flange that protrudes from an end portion on an opposite side to the bottom wall in the peripheral wall, and a second exterior member is attached to the flange. In each exterior part, the dimension in the height direction is smaller than the dimension in the vertical direction, and the dimension in the vertical direction is smaller than the dimension in the horizontal direction. For each of the batteries, the vertical direction is along the array direction, and in the battery array, a first battery having a bottom wall facing the base plate and a second battery having a second exterior member facing the base plate are adjacent to each other.

Description

Battery modules, battery packs and vehicles

Embodiments of the present invention relate to battery modules, battery packs and vehicles.

A battery such as a secondary battery includes an electrode group including a positive electrode and a negative electrode, and an exterior portion in which an internal cavity for accommodating the electrode group is formed. Some batteries have an exterior portion formed of a metal such as stainless steel, and an exterior portion formed of two exterior members, a first exterior member and a second exterior member. In this battery, the first exterior member is formed in the shape of a bottomed container having a bottom wall and a peripheral wall, and the peripheral wall surrounds the outer peripheral side of the internal cavity. A flange is formed on the first exterior member, and the flange projects from the end portion of the peripheral wall opposite to the bottom wall to the outer peripheral side. In this battery, the second exterior member faces the flange from the side opposite to the bottom wall and is welded to the flange. In a battery having an exterior portion as described above, the height dimension between the bottom wall and the second exterior member intersects the height direction in the vertical direction, and the height direction and It is smaller than each of the horizontal dimensions that intersect with the vertical direction, and the exterior portion is formed in a flat shape.

Further, as a battery module, there is a battery module provided with a plurality of batteries having a flat outer portion having a small dimension in the height direction. In such a battery module, a plurality of batteries are electrically connected via a bus bar or the like. In such a battery module, it is required that the heat generated in each of the batteries is appropriately dissipated. Further, it is required to reduce the volume of the entire battery module and secure a high volume energy density of the battery module.

Japanese Patent Application Laid-Open No. 2009-9445 Japanese Patent Application Laid-Open No. 2014-157721

The problem to be solved by the present invention is to provide a battery module in which heat generated in each battery is appropriately dissipated and a high volumetric energy density is secured, a battery pack including the battery module, and the battery pack. The purpose is to provide a vehicle to be equipped.

According to the embodiment, the battery module includes a battery array and a base plate. The battery array includes a plurality of batteries arranged in the arrangement direction, and the battery array is installed on the installation surface of the base plate. Each of the plurality of batteries includes an electrode group including a positive electrode and a negative electrode, and an exterior portion formed of metal and defining an internal cavity in which the electrode group is housed. Each exterior portion of the plurality of batteries includes a first exterior member and a second exterior member, and the first exterior member includes a bottom wall, a peripheral wall surrounding the outer peripheral side of the internal cavity, and a bottom wall in the peripheral wall. Includes a flange that projects from the opposite end to the outer peripheral side. The second exterior member is attached to the flange from the side opposite to the bottom wall in the height direction. In each of the exterior and internal cavities of the plurality of batteries, the dimensions in the height direction are smaller than the dimensions in the vertical direction intersecting the height directions, and the dimensions in the vertical direction are higher. It is smaller than the dimensions in the horizontal direction that intersect both the directional and vertical directions. Each of the plurality of batteries is arranged so that the vertical direction is along the arrangement direction. The plurality of batteries include a first battery in which the bottom wall faces the installation surface of the base plate and a second battery in which the second exterior member faces the installation surface of the base plate. The first battery and the second battery are arranged next to each other.

Further, according to the embodiment, a battery pack including the above-mentioned battery module is provided.

Further, according to the embodiment, a vehicle equipped with the above-mentioned battery pack is provided.

FIG. 1 is a perspective view schematically showing an example of a battery according to an embodiment. FIG. 2 is a perspective view schematically showing the battery of FIG. 1 disassembled for each member. FIG. 3 is a schematic view showing the configuration of the electrode group of the battery of FIG. FIG. 4 is a schematic view showing an electrical connection configuration between an electrode group and one of a pair of electrode terminals in the battery of FIG. FIG. 5 is a perspective view schematically showing an example of the battery module according to the embodiment, omitting the cover. FIG. 6 is a perspective view schematically showing the battery module of FIG. 5 in a state of being viewed from a direction different from that of FIG. FIG. 7 is a perspective view schematically showing the battery module of FIG. 5 in a state of being covered with a cover. FIG. 8 is a perspective view schematically showing two adjacent batteries in the battery array of the battery module of FIG. FIG. 9 is a schematic view showing two adjacent batteries in the battery array of the battery module of FIG. 5 as viewed from one side in the second direction. FIG. 10 is a perspective view schematically showing two adjacent batteries in the battery array of the battery module of FIG. 5 in a state where the two batteries and the insulating member between the two batteries are separated from each other. .. FIG. 11 is a perspective view schematically showing a single insulating member provided in the battery array of the battery module of FIG. FIG. 12 is a schematic view showing a structure for attaching an insulating member to a base plate in the battery module of FIG. FIG. 13 is a schematic view showing a connection state of a bus bar to a target terminal of a certain battery in the battery module of FIG. FIG. 14 is a cross-sectional view schematically showing the configuration of the base plate of the battery module of FIG. FIG. 15 is a schematic view illustrating the installation of the battery array on the installation surface of the base plate in the battery module of FIG. FIG. 16 is a schematic view showing an example of a battery pack in which the battery module according to the embodiment is used. FIG. 17 is a schematic view showing an example of a vehicle in which the battery pack according to the embodiment is used.

Hereinafter, embodiments will be described with reference to the drawings. The battery module according to the embodiment includes a plurality of batteries.

[battery]
First, a single battery used in the battery module will be described. FIG. 1 shows an example of the battery 1 according to the embodiment. Further, FIG. 2 shows the battery 1 of FIG. 1 disassembled for each member. Each of the plurality of batteries provided in the battery module has the same configuration as the battery 1 described below. The battery 1 is, for example, a secondary battery.

As shown in FIGS. 1 and 2, the battery 1 includes an exterior portion 3. The exterior portion 3 is formed of a metal such as stainless steel. Examples of the metal other than stainless steel forming the exterior portion 3 include aluminum, aluminum alloy, iron, and plated steel. Further, an internal cavity 11 is formed inside the exterior portion 3. In the battery 1 and the exterior portion 3, the vertical direction (direction indicated by arrows X1 and X2), the horizontal direction (vertical or substantially vertical) intersecting the vertical direction (direction indicated by arrow Y1 and arrow Y2), and Height directions (directions indicated by arrows Z1 and Z2) that intersect (vertical or substantially vertical) with respect to both the vertical and horizontal directions are defined.

The exterior portion 3 includes a first exterior member (cup member) 5 and a second exterior member (lid member) 6. The first exterior member 5 is formed in the shape of a container with a bottom. In the present embodiment, the first exterior member 5 has a bottom wall 7 and a peripheral wall 4, and is formed in a substantially rectangular parallelepiped shape with one side open. The bottom wall 7 is located on one side (arrow Z1 side) in the height direction with respect to the internal cavity 11. Further, the peripheral wall 4 extends along the circumferential direction of the exterior portion 3, and the outer peripheral side of the internal cavity 11 is surrounded by the peripheral wall 4. The internal cavity 11 is adjacent to the peripheral wall 4 on the inner peripheral side.

Further, the internal space of the first exterior member 5 forms at least a part of the internal cavity 11 of the exterior portion 3, and opens toward the side opposite to the side where the bottom wall 7 is located. The opening edge of the opening of the internal space of the first exterior member 5 is formed on the peripheral wall 4 at the end opposite to the bottom wall 7. Here, in the battery 1 and the exterior portion 3, the direction along the opening edge of the internal space of the first exterior member 5 coincides with or substantially coincides with the circumferential direction. The side where the internal cavity 11 (internal space) is located with respect to the peripheral wall 4 is the inner peripheral side, and the side opposite to the inner peripheral side is the outer peripheral side.

The peripheral wall 4 includes two pairs of side walls 8 and 9. The pair of side walls (first side wall) 8 face each other with the internal cavity 11 interposed therebetween in the vertical direction. The pair of side walls (second side wall) 9 face each other with the internal cavity 11 interposed therebetween in the lateral direction. Each of the side walls 8 is continuously extended along the lateral direction between the side walls 9. Further, each of the side walls 9 is continuously extended along the vertical direction between the side walls 8.

The first exterior member 5 includes a flange 13. The flange 13 projects from the end of the peripheral wall 4 (side walls 8 and 9) opposite to the bottom wall 7 to the outer peripheral side. Therefore, the flange 13 projects toward the outer peripheral side with respect to the peripheral wall 4, and is formed apart from the bottom wall 7 in the height direction. The flange 13 is formed over the entire circumference in the circumferential direction of the exterior portion 3, and projects toward the outer periphery over the entire circumference in the circumferential direction of the exterior portion 3. Further, the flange 13 extends from the opening edge of the internal space of the first exterior member 5 toward the outer peripheral side.

In the present embodiment, the second exterior member 6 is a substantially plate-shaped member, and is formed, for example, in a substantially rectangular shape. The second exterior member 6 is attached to the flange 13 from the side opposite to the side where the bottom wall 7 is located in the height direction of the battery 1, and faces the flange 13 from the side opposite to the bottom wall 7. Then, the opening of the internal space of the first exterior member 5 is closed by the second exterior member 6. The second exterior member 6 includes a top wall 15 facing the bottom wall 7 with the internal cavity 11 interposed therebetween in the height direction. Therefore, the bottom wall 7 of the first exterior member 5 faces the second exterior member 6 (top wall 15) with the internal cavity 11 interposed therebetween in the height direction. Further, the peripheral wall 4 and the flange 13 are provided between the bottom wall 7 and the second exterior member 6 in the height direction.

The second exterior member 6 projects toward the outer peripheral side with respect to the peripheral wall 4 (side walls 8 and 9). Then, the second exterior member 6 projects toward the outer periphery over the entire circumference in the circumferential direction of the exterior portion 3. Further, in the present embodiment, the thickness direction of the plate-shaped second exterior member 6 coincides with or substantially coincides with the height direction of the battery 1 (exterior portion 3).

The second exterior member 6 is welded to the flange 13 in a state of being arranged on the side opposite to the bottom wall 7 with respect to the flange 13. At the welded portion, the flange 13 and the second exterior member 6 are airtightly welded. The welded portion of the flange 13 to the second exterior member 6 is formed on the outer peripheral side of the exterior portion 3 with respect to the opening edge of the internal space of the first exterior member 5. Further, the welded portions of the flange 13 and the second exterior member 6 are continuously formed over the entire circumference in the circumferential direction. Therefore, the internal cavity of the exterior portion 3 is sealed and sealed. In the welded portion, the flange 13 and the second exterior member 6 are welded by, for example, resistance seam welding. By performing resistance seam welding, the cost is suppressed as compared with laser welding and the like, and the airtightness between the flange 13 and the second exterior member 6 is high.

In the present embodiment, the height dimension between the bottom wall 7 and the second exterior member 6 (top wall 15) is the vertical dimension between the pair of side walls (first side wall) 8. And, in the lateral direction between the pair of side walls (second side wall) 9, they are much smaller than each of the dimensions. Therefore, in the internal cavity 11, the dimensions in the height direction are much smaller than the dimensions in the vertical direction and the dimensions in the horizontal direction. Further, the wall thickness of the exterior portion 3 is formed uniformly or substantially uniformly over the entire exterior portion 3 (exterior members 5, 6). The wall thickness of the exterior portion 3 is thin, for example, 0.02 mm or more and 0.3 mm or less. Therefore, in the battery 1, the dimensions in the height direction are much smaller than the dimensions in the vertical direction and the dimensions in the horizontal direction. That is, the exterior portion 3 is formed in a flat shape in which the height direction dimension is smaller than the vertical dimension and the horizontal dimension respectively.

Further, in the present embodiment, the dimension in the vertical direction between the pair of side walls 8 is smaller than the dimension in the horizontal direction between the pair of side walls 9. Therefore, in the internal cavity 11, the dimension in the vertical direction is smaller than the dimension in the horizontal direction. Then, in the battery 1, the dimension in the vertical direction is smaller than the dimension in the horizontal direction. Further, the protruding dimensions of the flange 13 and the second exterior member 6 from the peripheral wall 4 to the outer peripheral side are about 2 mm or more and 5 mm or less. In the present embodiment, the outer peripheral end E of the exterior portion 3 (battery 1) is formed by the protruding ends of the flange 13 and the protruding portion of the second exterior member 6.

Since the exterior portion 3 (exterior members 5 and 6) has the above-described configuration, the area of the outer surface of each of the bottom wall 7 and the second exterior member 6 (top wall 15) is a pair of side walls (first). Side wall) 8 is larger than the area of each outer surface. The area of each outer surface of the side wall 8 is larger than the area of each outer surface of the pair of side walls (second side wall) 9. Further, the dimensions of the side wall 8 in each lateral direction are larger than the dimensions of the side wall 9 in each vertical direction.

The electrode group 10 is housed in the internal cavity 11 of the exterior portion 3. FIG. 3 is a diagram illustrating the configuration of the electrode group 10. As shown in FIG. 3, the electrode group 10 is formed in a flat shape, for example, and includes a positive electrode 21, a negative electrode 22, and separators 23 and 25. The positive electrode 21 includes a positive electrode current collector foil 21A as a positive electrode current collector and a positive electrode active material-containing layer 21B supported on the surface of the positive electrode current collector foil 21A. The positive electrode current collecting foil 21A is an aluminum foil, an aluminum alloy foil, or the like, and has a thickness of about 10 μm to 20 μm. A slurry containing a positive electrode active material, a binder and a conductive agent is applied to the positive electrode current collector foil 21A. Examples of the positive electrode active material include, but are not limited to, oxides, sulfides, polymers, and the like that can occlude and release lithium. Further, from the viewpoint of obtaining a high positive electrode potential, it is preferable to use lithium manganese composite oxide, lithium nickel composite oxide, lithium cobalt composite oxide, iron lithium phosphate or the like as the positive electrode active material.

The negative electrode 22 includes a negative electrode current collector foil 22A as a negative electrode current collector and a negative electrode active material-containing layer 22B supported on the surface of the negative electrode current collector foil 22A. The negative electrode current collecting foil 22A is an aluminum foil, an aluminum alloy foil, a copper foil, or the like, and has a thickness of about 10 μm to 20 μm. A slurry containing a negative electrode active material, a binder and a conductive agent is applied to the negative electrode current collector foil 22A. The negative electrode active material is not particularly limited, and examples thereof include metal oxides, metal sulfides, metal nitrides, and carbon materials capable of occluding and releasing lithium ions. As the negative electrode active material, a substance having a lithium ion occlusion / release potential of 0.4 V or more with respect to the metallic lithium potential, that is, a lithium ion occlusion / release potential of 0.4 V (vs. Li ⁺ / Li) or more. It is preferably a substance. By using a negative electrode active material having such a lithium ion occlusion / release potential, the alloy reaction between aluminum or an aluminum alloy and lithium is suppressed. Therefore, aluminum and aluminum and the constituent members related to the negative electrode current collecting foil 22A and the negative electrode 22 are used. Aluminum alloy can be used. Examples of the negative electrode active material in which the storage / release potential of lithium ions is 0.4 V (vs. Li ⁺ / Li) or more include titanium oxide, lithium titanium composite oxide such as lithium titanate, tungsten oxide, and amorphous tin. Examples thereof include oxides, niobium-titanium composite oxides, tin silicon oxides, silicon oxide and the like, and it is particularly preferable to use lithium titanium composite oxides as the negative electrode active material. When a carbon material that occludes and releases lithium ions is used as the negative electrode active material, it is preferable to use a copper foil for the negative electrode current collecting foil 22A. The carbon material used as the negative electrode active material has an occlusion / release potential of lithium ions of about 0 V (vs. Li ⁺ / Li).

The aluminum alloy used for the positive electrode current collecting foil 21A and the negative electrode current collecting foil 22A preferably contains one or more elements selected from Mg, Ti, Zn, Mn, Fe, Cu and Si. The purity of aluminum and aluminum alloy can be 98% by weight or more, preferably 99.99% by weight or more. Further, pure aluminum having a purity of 100% can be used as a material for the positive electrode current collector and / or the negative electrode current collector. The content of transition metals such as nickel and chromium in aluminum and aluminum alloys is preferably 100 ppm by weight or less (including 0 ppm by weight).

In the positive electrode current collecting foil 21A, the positive electrode current collecting tab 21D is formed by one long side edge 21C and a portion in the vicinity thereof. In one example of FIG. 3, the positive electrode current collecting tab 21D is formed over the entire length of the long edge 21C. In the positive electrode current collecting tab 21D, the positive electrode active material-containing layer 21B is not supported on the surface of the positive electrode current collecting foil 21A. Therefore, the positive electrode current collecting foil 21A includes a positive electrode current collecting tab 21D as a portion where the positive electrode active material-containing layer 21B is not supported. Further, in the negative electrode current collecting foil 22A, the negative electrode current collecting tab 22D is formed by one long side edge 22C and a portion in the vicinity thereof. In one example of FIG. 3, the negative electrode current collecting tab 22D is formed over the entire length of the long side edge 22C. In the negative electrode current collecting tab 22D, the negative electrode active material-containing layer 22B is not supported on the surface of the negative electrode current collecting foil 22A. Therefore, the negative electrode current collecting foil 22A includes a negative electrode current collecting tab 22D as a portion where the negative electrode active material-containing layer 22B is not supported.

Each of the separators 23 and 25 is formed of an electrically insulating material, and electrically insulates between the positive electrode 21 and the negative electrode 22. Each of the separators 23 and 25 may be a sheet or the like separate from the positive electrode 21 and the negative electrode 22, or may be integrally formed with one of the positive electrode 21 and the negative electrode 22. Further, the separators 23 and 25 may be formed of an organic material, an inorganic material, or a mixture of the organic material and the inorganic material. Examples of the organic material forming the separators 23 and 25 include engineering plastics and super engineering plastics. Examples of engineering plastics include polyamide, polyacetal, polybutylene terephthalate, polyethylene terephthalate, syndiotactic polystyrene, polycarbonate, polyamideimide, polyvinyl alcohol, polyvinylidene fluoride, and modified polyphenylene ether. Examples of the superempura include polyphenylene sulfide, polyetheretherketone, liquid crystal polymer, polyvinylidene fluoride, polytetrafluoroethylene (PTFE), polyethernitrile, polysulfone, polyacrylate, polyetherimide, and thermoplastic polyimide. Be done. Examples of the inorganic material forming the separators 23 and 25 include oxides (for example, aluminum oxide, silicon dioxide, magnesium oxide, phosphor oxide, calcium oxide, iron oxide, titanium oxide) and nitrides (for example, boron nitride, etc.). (Aluminum nitride, silicon nitride, barium nitride) and the like.

In the electrode group 10, the positive electrode 21, the negative electrode 22, and the separators 23 and 25 are wound shaft B with the separators 23 and 25 sandwiched between the positive electrode active material-containing layer 21B and the negative electrode active material-containing layer 22B. It is wound into a flat shape around the center. The positive electrode 21, the separator 23, the negative electrode 22, and the separator 25 are wound in a state of being stacked in this order, for example. Further, in the electrode group 10, the positive electrode current collecting tab 21D of the positive electrode current collecting foil 21A projects to one side in the direction along the winding axis B with respect to the negative electrode 22 and the separators 23 and 25. Then, the negative electrode current collecting tab 22D of the negative electrode current collecting foil 22A protrudes from the positive electrode 21 and the separators 23 and 25 on the side opposite to the side on which the positive electrode current collecting tab 21D protrudes in the direction along the winding axis B. To do.

The electrode group 10 is arranged so that the winding shaft B is parallel or substantially parallel to the lateral direction of the battery 1. Therefore, in the internal cavity 11 of the exterior portion 3, the positive electrode current collecting tab 21D projects to one side in the lateral direction with respect to the negative electrode 22 and the separators 23 and 25. Then, the negative electrode current collecting tab 22D projects laterally to the positive electrode 21 and the separators 23 and 25 on the side opposite to the side on which the positive electrode current collecting tab 21D protrudes.

Further, the electrode group 10 does not need to have a winding structure in which the positive electrode, the negative electrode and the separator are wound. In one embodiment, the electrode group 10 has a stack structure in which a plurality of positive electrodes and a plurality of negative electrodes are alternately laminated, and a separator is provided between the positive electrode and the negative electrode. Also in this case, in the electrode group 10, the positive electrode current collecting tab protrudes to one side in the lateral direction of the battery 1 (exterior portion 3) with respect to the negative electrode. Then, in the electrode group, the negative electrode current collecting tab protrudes with respect to the positive electrode in the lateral direction of the battery 1 to the side opposite to the side on which the positive electrode current collecting tab protrudes.

In one embodiment, the electrode group 10 is impregnated with an electrolytic solution (not shown) in the internal cavity 11. As the electrolytic solution, a non-aqueous electrolytic solution is used. For example, a non-aqueous electrolytic solution prepared by dissolving an electrolyte in an organic solvent is used. In this case, as the electrolyte to be dissolved in the organic solvent, lithium perchlorate (LiClO ₄ ), lithium hexafluorophosphate (LiPF ₆ ), lithium tetrafluoroborate (LiBF ₄ ), lithium hexafluoroarsenide (LiAsF ₆₎ ), Lithium salts such as lithium trifluoromethanesulfonate (LiCF ₃ SO ₃ ) and bistrifluoromethylsulfonylimide lithium [LiN (CF ₃ SO ₂ ) ₂ ], and mixtures thereof. Further, as the organic solvent, cyclic carbonates such as propylene carbonate (PC), ethylene carbonate (EC) and vinylene carbonate; chain carbonates such as diethyl carbonate (DEC), dimethyl carbonate (DMC) and methyl ethyl carbonate (MEC); tetrahydrofuran. Cyclic ethers such as (THF), dimethyltetrahydrofuran (2MeTHF), and dioxolane (DOX); chain ethers such as dimethoxyethane (DME) and diethoxyethane (DEE); γ-butyrolactone (GBL), acetonitrile (AN). And sulfolane (SL) and the like. These organic solvents are used alone or as a mixed solvent.

Further, in a certain embodiment, as the non-aqueous electrolyte, a gel-like non-aqueous electrolyte in which a non-aqueous electrolyte solution and a polymer material are composited is used instead of the electrolyte solution. In this case, the above-mentioned electrolyte and organic solvent are used. Examples of the polymer material include polyvinylidene fluoride (PVdF), polyacrylonitrile (PAN), polyethylene oxide (PEO) and the like.

Further, in a certain embodiment, instead of the electrolytic solution, a solid electrolyte such as a polymer solid electrolyte and an inorganic solid electrolyte is provided as a non-aqueous electrolyte. In this case, the electrodes 23 and 25 may not be provided in the electrode group 10. Then, in the electrode group 10, instead of the separators 23 and 25, a solid electrolyte is sandwiched between the positive electrode 21 and the negative electrode 22. Therefore, in this embodiment, the solid electrolyte electrically insulates between the positive electrode 21 and the negative electrode 22. Further, in some examples, an aqueous electrolyte containing an aqueous solvent instead of the non-aqueous electrolyte may be used as the electrolyte.

As shown in FIGS. 1 and 2, a pair of electrode terminals 27 are attached to the outer surface of the exterior portion 3. One of the electrode terminals 27 serves as the positive electrode terminal of the battery 1, and the other of the electrode terminals 27 serves as the negative electrode terminal of the battery 1. Therefore, the electrode terminals 27 have opposite polarities with respect to each other. Further, in the embodiment shown in FIG. 1 and the like, a pair of inclined surfaces 26 are formed on the outer surface of the first exterior member 5. Each of the inclined surfaces 26 is provided between the corresponding one side wall (second side wall) 9 and the bottom wall 7. Each of the pair of inclined surfaces 26 extends continuously along the longitudinal direction between the side walls 8. Therefore, each of the inclined surfaces 26 is extended over the same or substantially the same range as the corresponding one of the side walls 9 in the circumferential direction of the battery 1 (exterior portion 3). Each of the inclined surfaces 26 is inclined with respect to the bottom wall 7 and the side wall 9. Each of the inclined surfaces 26 is inclined inward in the lateral direction as it approaches the bottom wall 7.

In the embodiment shown in FIG. 1 and the like, each of the electrode terminals 27 is attached to the corresponding one of the inclined surfaces 26 in a state of being exposed to the outside. Therefore, each of the electrode terminals 27 is provided in the circumferential direction of the exterior portion 3 within a range in which one of the side walls (second side wall) 9 extends. In an example such as FIG. 1 and FIG. 2, each of the electrode terminals 27 is arranged at the corresponding center position or substantially center position of the inclined surface 26 in the vertical direction. Then, the electrode group 10 is arranged between the pair of electrode terminals 27 in the lateral direction. Each of the electrode terminals 27 is formed of a conductive material, for example, from any of aluminum, copper, stainless steel, and the like.

Further, a pair of insulating members 28 electrically formed from an insulating material are provided on the outer surface of the first exterior member 5. Each of the insulating members 28 is arranged on one of the corresponding outer surfaces of the side wall 9 and on the corresponding one of the inclined surfaces 26. Each of the insulating members 28 is interposed between the corresponding one of the inclined surfaces 26 and the corresponding one of the electrode terminals 27, and the corresponding one of the electrode terminals 27 is provided with respect to the exterior portion 3 (first exterior member 5). Electrically insulate.

FIG. 4 shows an electrical connection configuration between the electrode group 10 and one of the pair of electrode terminals 27. As shown in FIG. 4, the positive electrode current collecting tabs 21D of the electrode group 10 are bundled by welding such as ultrasonic welding. Then, the bundle of the positive electrode current collecting tab 21D is connected to one of the electrode terminals 27 (positive electrode terminal) via one or more positive electrode leads including the positive electrode backup lead 31A, the positive electrode relay lead 32A, the positive electrode terminal lead 33A, and the like. It is electrically connected. The connection between the positive electrode current collecting tab 21D and the positive electrode lead, the connection between the positive electrode leads, and the connection between the positive electrode lead and the positive electrode terminal are performed by welding such as ultrasonic welding. Here, the positive electrode lead is formed of a conductive metal. Further, the positive electrode terminal (corresponding one of 27), the positive electrode current collecting tab 21D, and the positive electrode lead are electrically insulated from the exterior portion 3 (exterior members 5, 6) by an insulating member (not shown) or the like. ..

Similarly, the negative electrode current collecting tab 22D of the electrode group 10 is bundled by welding such as ultrasonic welding. Then, the bundle of the negative electrode current collecting tab 22D is connected to one of the electrode terminals 27 (negative electrode terminal) via one or more negative electrode leads including the negative electrode backup lead 31B, the negative electrode relay lead 32B, the negative electrode terminal lead 33B, and the like. It is electrically connected. The connection between the negative electrode current collecting tab 22D and the negative electrode lead, the connection between the negative electrode leads, and the connection between the negative electrode lead and the negative electrode terminal are performed by welding such as ultrasonic welding. Here, the negative electrode lead is formed of a conductive metal. Further, the negative electrode terminal (corresponding one of 27), the negative electrode current collecting tab 22D, and the negative electrode lead are electrically insulated from the exterior portion 3 (exterior members 5, 6) by an insulating member (not shown) or the like. ..

Further, in the internal cavity 11, spaces are formed on both sides of the electrode group 10 in the lateral direction. That is, a space is formed between each inner surface of the side wall (second side wall) 9 and the electrode group 10. In each of the pair of spaces, the corresponding one of the positive electrode current collecting tab 21D and the negative electrode current collecting tab 22D is arranged, and the corresponding one of the positive electrode lead and the negative electrode lead is arranged.

As described above, in each of the exterior portion 3 and the internal cavity 11 of the battery 1, the dimensions in the height direction are much smaller than the dimensions in the vertical direction, and the dimensions in the vertical direction are the dimensions in the horizontal direction. It is smaller than the size. Therefore, the electrode group 10 and the like of the internal cavity 11 easily come into contact with the bottom wall 7 and the second exterior member 6 (top wall 15), but are difficult to come into contact with each of the side walls 8. Therefore, a gap is likely to be formed between each of the electrode group 10 and the side wall (first side wall) 8. Further, a space is formed between the electrode group 10 and each of the side wall (second side wall) 9 as described above. Further, in the battery 1, as described above, the area of each outer surface of the bottom wall 7 and the second exterior member 6 (top wall 15) is larger than the area of each outer surface of the side walls 8 and 9. large. Due to the above-described configuration, in the battery 1, the heat dissipation from each of the bottom wall 7 and the top wall 15 to the outside is higher than the heat dissipation from each of the side walls 8 and 9 to the outside.

Also, the wall thickness of the exterior part 3 is thin as described above. Therefore, the thermal conductivity between the peripheral wall 4 (side walls 8 and 9) and the bottom wall 7 is low. Similarly, the thermal conductivity between the peripheral wall 4 (side walls 8 and 9) and the top wall 15 (second exterior member 6) is also low. Further, the battery 1 (exterior portion 3) has a large size in the lateral direction and a small size in the height direction. Therefore, the battery 1 is easily bent in a state in which the amount of bending in the height direction changes along the lateral direction.

In a modified example, a plurality of electrode groups may be housed in the internal cavity 11. Further, in another modification, the second exterior member (lid member) 6 is not formed in a plate shape, but is formed in a substantially rectangular parallelepiped shape having one surface open like the first exterior member 5. In this case, the second exterior member 6 includes, in addition to the top wall 15, a peripheral wall and a flange, similarly to the first exterior member 5. Then, the flange 13 of the first exterior member 5 and the flange of the second exterior member 6 are airtightly welded. However, in any of the modified examples, the battery 1 (exterior portion 3) is formed into a flat shape in which the dimensions in the height direction are smaller than the dimensions in the vertical direction and the dimensions in the horizontal direction. In any case, in the internal cavity 11, the dimension in the height direction between the bottom wall 7 and the second exterior member 6 (top wall 15) is that of the pair of side walls (first side wall) 8. It is smaller than the dimension in the vertical direction between them, and the dimension in the vertical direction is smaller than the dimension in the horizontal direction between the pair of side walls (second side wall) 9.

[Battery module]
Next, the battery module will be described. The battery module according to the embodiment includes a plurality of the above-mentioned flat-shaped batteries 1 having a small dimension in the height direction. 5 to 7 show an example of the battery module 40 according to the embodiment. As shown in FIGS. 5 and 6, the battery module 40 includes one or more battery arrays 41A, 41B, and a base plate 42. In the embodiment shown in FIG. 5 and the like, two battery arrays 41A and 41B are provided. Here, in the battery module 40, in the first direction (direction indicated by arrows X3 and X4), in the second direction (vertical or substantially vertical) intersecting with the first direction (arrow Y3 and arrow Y4). The direction indicated) and the third direction (vertical or substantially vertical) intersecting (vertical or substantially vertical) with respect to both the first and second directions (directions indicated by arrows Z3 and Z4) are defined. 5 and 6 show the battery module 40 by omitting the covers 61A and 61B described later. Further, in FIGS. 5 and 6, the viewing directions are different from each other.

The outer surface of the base plate 42 includes installation surfaces (main surfaces) 45 and 46. The installation surface (first installation surface) 45 faces one side (arrow Z3 side) in the third direction. The installation surface (second installation surface) 46 faces the side opposite to the installation surface 45 (arrow Z4 side) in the third direction. In the embodiment shown in FIG. 5 and the like, the battery array (first battery array) 41A is installed on the installation surface 45, and the battery array (second battery array) 41B is installed on the installation surface 46. Therefore, the base plate 42 is interposed between the battery arrays 41A and 41B. Further, the base plate 42 is arranged in a state where the thickness direction coincides with or substantially coincides with the third direction.

In each of the battery arrays 41A and 41B, a plurality of batteries 1 are arranged along the arrangement direction. In the embodiment shown in FIG. 5 and the like, five batteries 1 are arranged in each of the battery arrays 41A and 41B. The arrangement direction of the batteries 1 in each of the battery arrangements 41A and 41B coincides with or substantially coincides with the first direction. Further, in the embodiment shown in FIG. 5 and the like, the arrangement direction of the batteries 1 in the battery array (first battery array) 41A is the arrangement direction of the batteries 1 in the battery array (second battery array) 41B. And match or substantially match. In each of the battery arrays 41A and 41B, the vertical direction of each of the batteries 1 coincides with or substantially coincides with the arrangement direction (first direction), and the horizontal direction coincides with or substantially coincides with the second direction. And will be placed. That is, each of the batteries 1 is arranged in a state in which the vertical direction is along the arrangement direction. Therefore, in each of the battery arrays 41A and 41B, each of the batteries 1 is arranged in a state in which the height direction coincides with or substantially coincides with the third direction.

The plurality of batteries 1 used in the battery module 40 are formed to have the same or substantially the same dimensions with respect to each other. Further, in each of the battery arrays 41A and 41B, the plurality of batteries 1 are arranged in the second direction (the lateral directions of the batteries 1) with respect to each other or with almost no deviation from each other. .. Then, in each of the battery arrays 41A and 41B, the plurality of batteries 1 are arranged in a third direction (in each height direction of the battery 1) with no deviation from each other or with almost no deviation from each other. To.

As shown in FIG. 7 and the like, the battery arrays 41A and 41B and the base plate 42 are housed inside the covers 61A and 61B and the like. Each of the covers 61A and 61B is formed of, for example, a resin and has electrical insulation. Further, each of the covers 61A and 61B is formed in a cup shape and is formed in a substantially rectangular parallelepiped shape having one side open. The cover 61A covers the battery array 41A from one side in the third direction. Further, the cover 61B covers the battery array 41B from the side opposite to the cover 61A in the third direction.

A plurality of engaging grooves 65 recessed toward the inner peripheral side are formed on the outer edge of the base plate 42. Further, a plurality of engaging claws 66A are provided on the opening edge of the cover 61A, and a plurality of engaging claws 66B are provided on the opening edge of the cover 61B. Each of the engaging claws 66A, 66B engages with the corresponding one of the engaging grooves 65. As a result, each of the covers 61A and 61B is fixed to the base plate 42. Further, one or more engaging pieces 67A are provided on the opening edge of the cover 61A, and one or more engaging pieces 67B are provided on the opening edge of the cover 61B. Each of the engaging pieces 67A engages with the corresponding one of the engaging pieces 67B to the extent that the base plate 42 is not extended. As a result, the covers 61A and 61B are fixed to each other.

8 to 10 show two batteries 1 adjacent to each other in the arrangement direction in the battery arrangement 41A (41B). Here, FIG. 8 shows a perspective view, and FIG. 9 shows a state viewed from one side in the second direction (horizontal direction of each battery). As shown in FIGS. 8 to 10, each of the battery arrays 41A and 41B includes an insulating member 43. The insulating member 43 is formed of a resin or the like and has electrical insulating properties. In each of the battery arrays 41A and 41B, each of the batteries 1 sandwiches the insulating member 43 with each of the adjacent batteries 1 in the arrangement direction. Therefore, the insulating member 43 is interposed between the two batteries 1 adjacent to each other in the arrangement direction. Note that FIG. 10 shows a state in which the two adjacent batteries 1 and the insulating member 43 between the two batteries 1 are separated from each other. Further, in an example such as FIG. 5, five batteries are provided in each of the battery arrays 41A and 41B. Therefore, four insulating members 43 are provided in each of the battery arrays 41A and 41B.

As described above, each of the batteries 1 is arranged in a state where the vertical direction is along the arrangement direction. Therefore, in each of the batteries 1 of the battery arrays 41A and 41B, one of the pair of side walls (first side wall) 8 corresponding to each of the adjacent batteries 1 in the arrangement direction is the insulating member 43. Oppose each other across. Here, the batteries 1α and 1γ arranged at both ends in the arrangement direction are defined in the battery array 41A, and the batteries 1β and 1δ arranged at both ends in the arrangement direction in the battery array 41B. In each of the batteries 1α, 1β, 1γ, and 1δ, the other batteries 1 are adjacent to each other only on one side in the arrangement direction. Further, in each of the batteries 1 other than the batteries 1α, 1β, 1γ, and 1δ, the other batteries 1 are adjacent to each other on both sides in the arrangement direction. Therefore, in each of the batteries 1, one or two batteries 1 are adjacent to each other in the arrangement direction.

Further, the plurality of batteries 1 forming the battery arrays 41A and 41B include a first battery 1A and a second battery 1B. In the first battery 1A, the bottom wall 7 faces one of the corresponding installation surfaces 45, 46 of the base plate 42. In the second battery 1B, the second exterior member 6 (top wall 15) faces the corresponding one of the installation surfaces 45, 46 of the base plate 42. In each of the battery arrays 41A and 41B, the first battery 1A and the second battery 1B are alternately arranged in the arrangement direction. Therefore, the first battery 1A and the second battery 1B are arranged next to each other in the arrangement direction. In an embodiment such as FIG. 5, in each of the battery arrays 41A and 41B, the plurality of batteries 1 include two first batteries 1A and three second batteries 1B. The batteries 1α, 1β, 1γ, and 1δ are all the first batteries 1A.

FIG. 11 shows the insulating member 43 alone, and FIG. 12 shows the mounting structure of the insulating member 43 on the base plate 42. As shown in FIG. 11 and the like, each of the insulating members 43 is a bar member extending along the longitudinal direction, and each of the insulating members 43 has a larger dimension in the longitudinal direction. In the battery module 40, each of the insulating members 43 is arranged in a state in which the longitudinal direction coincides with or substantially coincides with the second direction. Therefore, in each of the battery arrays 41A and 41B, each of the insulating members 43 is arranged in a state in which the longitudinal direction coincides with the lateral direction of the battery 1. The dimensions of the insulating member 43 in the longitudinal direction are the same as or substantially the same as the dimensions of the side wall (first side wall) 8 in the lateral direction of each battery 1.

In each of the batteries 1 of the battery array 41A and 41B, the peripheral wall 4 abuts on each of the insulating members 43 adjacent in the array direction. In each of the batteries 1, the corresponding one of the side walls (first side wall) 8 is in contact with each of the adjacent insulating members 43, and the corresponding one of the side walls 8 is bonded by adhesion or the like. As a result, each of the batteries 1 (exterior portion 3) is fixed to each of the adjacent insulating members 43. In each of the batteries 1, the corresponding one side wall 8 abuts against each of the adjacent insulating members 43 in the lateral direction over the entire length or substantially the entire length. Further, each of the batteries 1 is fixed to each of the adjacent insulating members 43 in a state of receiving a pressing force inward in the vertical direction from each of the adjacent batteries 1.

Further, each of the insulating members 43 is provided with one or more engaging protrusions 62. In the embodiment shown in FIG. 11 and the like, two engaging protrusions 62 are provided on each of the insulating members 43. Further, as shown in FIG. 12 and the like, a plurality of engaging holes 63 are formed on the installation surface 45 of the base plate 42. In the battery array 41A, each of the engaging projections 62 of the insulating member 43 engages with the corresponding one of the engaging holes 63. Each of the insulating members 43 is positioned in the first direction and the second direction with respect to the installation surface 45 of the base plate 42 by engaging each of the engaging protrusions 62 with the corresponding one of the engaging holes 63. Will be done. Then, each of the insulating members 43 is fixed to the installation surface 45 by adhesion or the like in a state of being positioned with respect to the installation surface 45. Further, each of the insulating members 43 is fixed to the installation surface 45 in a state of surface contact with the installation surface 45.

A plurality of engagement holes similar to the engagement holes 63 are formed on the installation surface 46 of the base plate 42. Then, each of the insulating members 43 of the battery array 41B is positioned in the first direction and the second direction with respect to the installation surface 46 of the base plate 42 in the same manner as the insulating member 43 of the battery array 41A. To. Then, each of the insulating members 43 is fixed to the installation surface 46 by adhesion or the like in a state of being positioned with respect to the installation surface 46. Further, each of the insulating members 43 is fixed to the installation surface 46 in a state of surface contact with the installation surface 46.

Further, in the battery array 41A, each of the batteries 1 is fixed to each of the adjacent insulating members 43 as described above. Therefore, by positioning the insulating member 43 with respect to the installation surface 45, each of the batteries 1 is also positioned with respect to the installation surface 45 in the first direction and the second direction. Similarly, in the battery array 41B as well, the insulating member 43 is positioned with respect to the installation surface 46 as described above, so that each of the batteries 1 also has a first direction and a second direction with respect to the installation surface 46. Is positioned. By positioning each of the batteries 1 with respect to the base plate 42, each pair of electrode terminals 27 of the battery 1 is also positioned with respect to the base plate 42 in the first direction and the second direction.

Further, in each of the battery arrays 41A and 41B, the outer surface of each bottom wall 7 of the first battery 1A comes into surface contact with the corresponding one of the installation surfaces 45 and 46. Then, each of the first batteries 1A is fixed to the corresponding one of the installation surfaces 45, 46 by adhesion or the like in a state where the outer surface of the bottom wall 7 is in surface contact with the corresponding one of the installation surfaces 45, 46. .. Further, in each of the battery arrays 41A and 41B, the outer surface of each of the second exterior members 6 (top wall 15) of the second battery 1B comes into surface contact with the corresponding one of the installation surfaces 45 and 46. Then, in each of the second batteries 1B, the outer surface of the second exterior member 6 is in surface contact with the corresponding one of the installation surfaces 45 and 46, and is adhered to the corresponding one of the installation surfaces 45 and 46 by adhesion or the like. It is fixed.

Further, the battery module 40 of the embodiment shown in FIG. 5 or the like is provided with a plurality of bus bars (first bus bars) 53 and bus bars 55, 56, 57. Each of the bus bars 53, 55 to 57 is formed of a conductive material such as metal.

In the embodiment shown in FIG. 5 and the like, each of the bus bars 53 electrically connects two batteries 1 adjacent to each other in the arrangement direction in each of the battery arrangements 41A and 41B. Here, a configuration for electrically connecting two adjacent batteries 1 via one bus bar 53 will be described. In each of the battery arrays 41A and 41B, each of the batteries 1 is electrically connected to each of the adjacent batteries 1 via one bus bar 53 as follows.

In each of the two batteries 1 electrically connected by the bus bar 53, the bus bar 53 comes into contact with the corresponding target terminal of the pair of electrode terminals 27. In each of the two batteries 1, the bus bar 53 is connected to the target terminal by welding or the like. The target terminals of the two batteries 1 are arranged on the same side with respect to the central position of the battery module 40 in the second direction. That is, the target terminals of the two batteries 1 are located on the same side with respect to the respective electrode group 10 of the battery 1 in each lateral direction of the battery 1. The bus bar 53 relays between the target terminals (first target terminals) of the two batteries 1. Then, in each of the battery arrays 41A and 41B, the bus bar 53 is located between the target terminals of the two batteries 1 along the arrangement direction (the first direction of the battery module 40), that is, each of the batteries 1. It is extended along the vertical direction.

In one example, three or more batteries 1 may be electrically connected by one bus bar 53. In this case as well, in each of the three or more batteries 1, the bus bar 53 comes into contact with the corresponding target terminal (first target terminal) of the pair of electrode terminals 27, and the bus bar 53 is connected to the target terminal. To. Then, the target terminals of the three or more batteries 1 are arranged on the same side with respect to the central position of the battery module 40 (each electrode group 10 of the battery 1) in the second direction. Then, in each of the battery arrays 41A and 41B, the bus bar 53 extends between the target terminals of the three or more batteries 1 along the arrangement direction, that is, along the respective vertical directions of the batteries 1. Will be done.

FIG. 13 shows the connection state of the bus bar 53 to the target terminal (corresponding one of 27) of a certain battery 1. As shown in FIG. 13, in each of the two or more batteries 1 electrically connected by one bus bar 53, the inner peripheral side with respect to the protruding end of the protruding portion of the flange 13 and the second exterior member 6 The bus bar 53 is located (inside). That is, in each of the batteries 1 electrically connected by one bus bar 53, the bus bar 53 is located between the peripheral wall 4 (corresponding side of the side wall 9) and the outer peripheral end E of the exterior portion 3 (battery 1). To do. Therefore, in each of the batteries 1, the bus bar 53 does not protrude from the outer peripheral end E of the exterior portion 3 to the outer peripheral side (outside) in the lateral direction. Then, in each of the battery arrays 41A and 41B, none of the bus bars 53 protrudes to the outer peripheral side (outside) with respect to the outer peripheral end E of each outer peripheral portion 3 of the battery 1 in the second direction.

Further, in the embodiment shown in FIG. 5 and the like, two adjacent batteries 1 are electrically connected in series by one bus bar 53. Therefore, the two target terminals connected by one bus bar 53 are one positive electrode terminal and the other negative electrode terminal. Further, in another example, in any of the battery arrays 41A and 41B, two or more batteries 1 may be electrically connected in parallel using two bus bars 53. In this case, the positive electrode terminals of the two or more batteries 1 are connected to each other by one of the two bus bars 53 on one side with respect to the central position of the battery module 40 in the second direction. Then, the negative electrode terminals of the two or more batteries 1 are connected to each other by the other of the two bus bars 53 on the other side with respect to the central position of the battery module 40 in the second direction.

Further, the battery module 40 of the embodiment shown in FIG. 5 or the like is provided with module terminals 51 and 52. Here, for example, the module terminal 51 is a module terminal on the positive electrode side, and the module terminal 52 is a module terminal on the negative electrode side. In the battery module 40, the battery arrays 41A and 41B are arranged in the first direction and the second direction with no deviation from each other or with almost no deviation from each other. The module terminals 51 and 52 are located on the same side with respect to the battery arrays 41A and 41B in the first direction. Further, the module terminals 51 and 52 are arranged apart from each other in the second direction. The module terminal 52 is arranged on the side opposite to the module terminal 51 with respect to the central position of the battery module 40 in the second direction. Further, each electrode group 10 of the battery 1 is located between the module terminals 51 and 52 in the second direction.

In the battery array 41A, the battery 1γ is arranged at the end near the module terminals 51 and 52 in the first direction (arrangement direction), and the battery is arranged at the end far from the module terminals 51 and 52 in the first direction. 1α is arranged. Further, in the battery array 41B, the battery 1δ is arranged at the end near the module terminals 51 and 52 in the first direction (arrangement direction), and the end far from the module terminals 51 and 52 in the first direction. The battery 1β is arranged in.

In the battery 1γ, the bus bar 53 is not connected to the pair of electrode terminals 27, while the bus bar 57 is in contact with the battery 1γ. Then, the bus bar 57 is connected to the corresponding one of the electrode terminals 27 of the battery 1γ. The battery 1γ is electrically connected to the module terminal 52 on the negative electrode side via the bus bar 57. The bus bar 57 extends from one of the electrode terminals 27 of the battery 1γ to the module terminal 52 in a substantially L shape. That is, the bus bar 57 extends outward from one of the corresponding electrode terminals 27 of the battery 1γ in the first direction, and extends along the corresponding one of the pair of side walls 9 of the battery 1γ. Then, in the region adjacent to the outside of the battery 1γ in the first direction, the bus bar 57 extends along the second direction to the module terminal 52 along the corresponding one of the pair of side walls 8 of the battery 1γ. It will be extended toward.

In the battery 1δ, the bus bar 53 is not connected to the pair of electrode terminals 27, while the bus bar 56 is in contact with the battery 1δ. Then, the bus bar 56 is connected to the corresponding one of the electrode terminals 27 of the battery 1δ. The battery 1δ is electrically connected to the module terminal 51 on the positive electrode side via the bus bar 56. The bus bar 56 extends outward from one of the corresponding electrode terminals 27 of the battery 1δ in the first direction and extends along the corresponding one of the pair of side walls 9 of the battery 1δ.

In the battery 1α, the bus bar (second bus bar) 55 comes into contact with the target terminal to which the bus bar 53 is not connected at the pair of electrode terminals 27. Then, the bus bar 55 is connected to the corresponding target terminal of the electrode terminal 27 of the battery 1α. Further, in the battery 1β, the bus bar 55 comes into contact with the target terminal on which the bus bar 53 is not connected at the pair of electrode terminals 27. Then, the bus bar 55 is connected to the corresponding target terminal of the electrode terminal 27 of the battery 1β. Therefore, one of the pair of electrode terminals 27 is used in each of the corresponding one (1α) of the plurality of batteries 1 of the battery array 41A and the corresponding one (1β) of the plurality of batteries 1 of the battery array 41B. The bus bar 55 comes into contact with the target terminal (second target terminal). As a result, the battery arrays 41A and 41B are electrically connected by the bus bar 55.

The target terminals of the two batteries 1α and 1β connected by the bus bar 55 are arranged on the same side with respect to the central position of the battery module 40 in the second direction. That is, the target terminals of the two batteries 1α and 1β are located on the same side with respect to the respective electrode groups 10 of the batteries 1α and 1β in the lateral directions of the batteries 1α and 1β. The bus bar 55 relays between the target terminals (second target terminals) of the two batteries 1α and 1β. Then, the bus bar 55 extends along the third direction between the target terminals of the two batteries 1α and 1β. That is, the bus bar 55 is extended along the direction intersecting the arrangement direction of the batteries 1 (the first direction of the battery module 40) in the battery arrangements 41A and 41B. Then, the bus bar 55 extends (beyond the base plate 42) across the base plate 42 between the target terminals (second target terminals) of the two batteries 1α and 1β.

In the present embodiment, the plurality of batteries 1 are electrically connected by each of the bus bars 53, 55 to 57 as described above. In an embodiment such as FIG. 5, a plurality of (10) batteries 1 forming the battery arrays 41A and 41B are electrically connected in series between the module terminals 51 and 52 by bus bars 53, 55 to 57. To. In the battery module 40, the respective exterior portions 3 (exterior members 5, 6) of the battery 1 do not come into contact with any of the bus bars 53, 55 to 57.

Further, in the embodiment shown in FIG. 5, the printed wiring board 71 is installed on the installation surface 45 of the base plate 42. The printed wiring board 71 is located on the side where the module terminals 51 and 52 are located with respect to the battery arrays 41A and 41B in the first direction. The printed wiring board 71 is located between the module terminals 51 and 52 in the second direction.

Further, FIG. 14 shows the configuration of the base plate 42. As shown in FIG. 14, the base plate 42 includes a plate-shaped base material 68 formed of metal. In the battery module 40, the base material 68 is arranged in a state where the thickness direction coincides with or substantially coincides with the third direction. Further, in the base plate 42, insulating layers 69 are formed on both surfaces of the base material 68. The insulating layer 69 is formed of, for example, a resin or the like, and has electrical insulating properties. An insulating layer 69 is formed on both sides of the base metal 68, either entirely or substantially entirely. The insulating layer 69 is formed by depositing or coating an insulating material on the surface of the base material 68. Further, the insulating layer 69 may be formed by adhering an insulating sheet or the like to the surface of the base material 68. In the embodiment shown in FIG. 5 and the like, the installation surface 45 on which the battery array 41A is installed and the installation surface 46 on which the battery array 41B is installed are formed from the insulating layer 69. Therefore, each of the batteries 1 is appropriately insulated from the base material 68.

FIG. 15 is a diagram illustrating the installation of the battery array 41A on the installation surface 45 of the base plate 42. As shown in FIG. 15, in the installation of the battery array 41A, first, each of the insulating members 43 is engaged with the corresponding one of the engaging holes 63 by engaging each of the engaging projections 62 with the installation surface 45. Attach to. At this time, each of the insulating members 43 is fixed to the installation surface 45 in a state of being in surface contact with the installation surface 45 and being positioned with respect to the base plate 42 in the first direction and the second direction. Then, each of the second batteries 1B in which the second exterior member 6 (top wall 15) faces the base plate 42 is attached to one or more corresponding one or more of the insulating members 43 and the installation surface 45. At this time, in each of the second batteries 1B, the outer surface of the second exterior member 6 was in surface contact with the installation surface 45, and each of the second batteries 1B was positioned with respect to the base plate 42 in the first direction and the second direction. In the state, it is fixed to one or more corresponding members of the insulating member 43 and the installation surface 45.

Further, the plurality of insulating members 43 are fixed to the installation surface 45 in a state where the interval (pitch) in the first direction is slightly smaller than the dimension in each vertical direction of the battery 1. That is, in the state where the insulating member 43 is fixed to the installation surface 45, the first direction of the insulating member 43 is compared with the vertical dimension between the outer surfaces of the pair of side walls 8 of each battery 1. The interval between is slightly smaller. Then, with the insulating member 43 and the second battery 1B attached to the installation surface 45, each of the first batteries 1A whose bottom wall 7 faces the base plate 42 is attached to one or more corresponding ones or more of the insulating member 43. And attach to the installation surface 45. At this time, each of the first batteries 1A is in a state where the outer surface of the bottom wall 7 is in surface contact with the installation surface 45 and is positioned with respect to the base plate 42 in the first direction and the second direction. It is fixed to one or more corresponding members of the insulating member 43 and the installation surface 45.

As described above, the distance between the plurality of insulating members 43 in the first direction is slightly smaller than the dimensions of the battery 1 in each vertical direction. Therefore, by mounting the first battery 1A on the installation surface 45, each of the batteries 1 receives a pressing force inward in the vertical direction from each of the adjacent batteries 1. The battery array 41B is also attached to the installation surface 46 in the same manner as the battery array 41A is attached to the installation surface 45.

In each of the battery arrangements 41A and 41B of the battery module 40 according to the above-described embodiment, each of the batteries 1 sandwiches the insulating member 43 between the batteries 1 adjacent to each other in the arrangement direction. Therefore, it is effectively prevented that the batteries 1 adjacent to each other are electrically conductive via a path other than the bus bar 53. As a result, the occurrence of a short circuit or the like is effectively prevented in each of the battery arrays 41A and 41B.

Further, in the above-described embodiment and the like, the installation surface 45 on which the battery array 41A is installed and the installation surface 46 on which the battery array 41B is installed are formed from the insulating layer 69. Therefore, the occurrence of a short circuit or the like is more effectively prevented in each of the battery arrays 41A and 41B. Further, it is also possible to effectively prevent a short circuit between the battery arrays 41A and 41B via the base metal 68. Therefore, the battery module 40 is formed with an insulating structure that effectively prevents short circuits and the like.

Further, in each of the first batteries 1A, the second exterior member 6 (top wall 15) is located on the side opposite to the side where the base plate 42 is located with respect to the internal cavity 11, and the second exterior member The outer surface of 6 faces outward in a third direction. Then, in each of the second batteries 1B, the bottom wall 7 is located on the side opposite to the side where the base plate 42 is located with respect to the internal cavity 11, and the outer surface of the bottom wall 7 is in the third direction. Turn to the outside. As described above, each exterior portion 3 of the battery 1 of the embodiment or the like is formed in a flat shape having a small dimension in the height direction. In each of the batteries 1, the area of the outer surface of each of the bottom wall 7 and the second exterior member 6 (top wall 15) is larger than the area of the outer surface of each of the side walls 8 and 9. Due to the above-described configuration, in each of the batteries 1, the heat dissipation from each of the bottom wall 7 and the top wall 15 to the outside is higher than the heat dissipation from each of the side walls 8 and 9 to the outside.

In the battery module 40 of the embodiment or the like, each of the batteries 1 is arranged so that the outer surface of the bottom wall 7 or the outer surface of the top wall 15 faces outward in the third direction. Therefore, in the battery module 40, the heat generated in each of the batteries 1 is dissipated to the outside through the bottom wall 7 or the second exterior member 6 (top wall 15). In each of the batteries 1, the bottom wall 7 or the second exterior member 6 having high heat dissipation dissipates heat to the outside, so that the generated heat is appropriately dissipated in the battery module 40. Therefore, the battery module 40 is appropriately cooled. Further, since each of the batteries 1 is arranged so that the outer surface of the bottom wall 7 or the outer surface of the top wall 15 faces outward in the third direction, it is easy to uniformly cool the entire battery module 40. Will be feasible.

Further, in each of the battery arrays 41A and 41B, the first battery 1A and the second battery 1B are arranged adjacent to each other, and the first battery 1A and the second battery 1B are arranged alternately in the arrangement direction. .. In each of the batteries 1 used in the battery module 40, the flange 13 and the second exterior member 6 project toward the outer peripheral side with respect to the peripheral wall 4. In the embodiment and the like, since the batteries 1 are arranged as described above, even if the batteries 1 having the above-described configuration are used, the dimensions in the arrangement direction can be reduced in each of the battery arrangements 41A and 41B. It will be possible. As the dimensions of the battery arrays 41A and 41B in the arrangement direction become smaller, the volumes of the battery arrays 41A and 41B become smaller. As a result, the volume energy densities of the battery arrays 41A and 41B are secured high, and the volume energy density of the battery module 40 is secured high.
Further, since the battery 1 has a large dimension in the lateral direction and a small dimension in the height direction, it bends in a state in which the amount of deflection in the height direction changes along the lateral direction as described above. easy. In each of the battery arrays 41A and 41B of the embodiment and the like, each of the batteries 1 is arranged in a state in which the vertical direction is along the array direction. Then, in each of the batteries 1, one of the corresponding side walls 8 faces each of the adjacent batteries 1 with the insulating member 43 interposed therebetween, and the side wall (first) is opposed to each of the adjacent insulating members 43. The corresponding one of the side walls) 8 is joined. Since each of the battery arrays 41A and 41B is assembled as described above, the battery arrays 41A and 41B having high strength are formed. As a result, in each of the battery arrays 41A and 41B, deformation of the battery 1 due to resonance or the like is suppressed.

Further, in the battery module 40, each of the batteries 1 is fixed to each of the adjacent insulating members 43 in a state of receiving a pressing force inward in the vertical direction from each of the adjacent batteries 1. Therefore, in each of the battery arrays 41A and 41B, the vibration of each of the batteries 1 is suppressed by the pressing force from each of the adjacent batteries 1. As a result, the deformation of each of the batteries 1 is suppressed more effectively. Further, even if there is a manufacturing tolerance of the battery 1, the manufacturing tolerance can be absorbed by receiving a pressing force inward from each of the adjacent batteries 1 in the vertical direction and compressing the battery 1.
Further, when assembling the battery module 40, by fixing the battery 1 with a two-component mixed adhesive having a long curing time, the battery 1 is slid on the base plate 42 at an appropriate position in the time until the battery 1 is cured. Can be fixed to. This not only facilitates assembly, but also makes the fixed position more accurate.

Further, in each of the batteries 1, one or more corresponding ones or more of the bus bars 53 are extended so as to pass between the peripheral wall 4 and the outer peripheral end E of the exterior portion 3 (battery 1). Therefore, in each of the battery arrays 41A and 41B, none of the bus bars 53 protrudes to the outer peripheral side (outside) with respect to the outer peripheral end E of each outer peripheral portion 3 of the battery 1 in the second direction. .. Since each of the bus bars 53 in each of the battery arrays 41A and 41B is located on the inner peripheral side with respect to the outer peripheral end E of each of the batteries 1, space loss is reduced in each of the battery arrays 41A and 41B. .. As a result, each of the battery arrays 41A and 41B can be further miniaturized, and the volumetric energy density of each of the battery arrays 41A and 41B can be further increased.

In a modified example, only one battery array similar to the battery arrays 41A and 41B is provided. In this case, one side of the base plate 42 is the installation surface on which the battery array is installed. In this modification as well, a plurality of batteries 1 are arranged in the battery array in the same manner as in each of the battery arrays 41A and 41B.

[Battery pack]
Next, a battery pack in which the battery module of the above-described embodiment or the like is used will be described. FIG. 16 shows an example of a battery pack 70 in which the battery module 40 of the embodiment shown in FIG. 5 or the like is used. In an embodiment such as FIG. 16, in the battery module 40, a plurality of batteries 1 are electrically connected in series. The batteries 1 are electrically connected to each other via the bus bars 53, 55 and the like described above. In another example, in the battery module 40, a plurality of batteries 1 may be electrically connected in parallel. Further, in another example, in the battery module 40, both a series connection in which the batteries 1 are connected in series and a parallel connection in which the batteries 1 are connected in parallel may be formed.

Further, in the battery module 40 of the battery pack 70, one (1δ) positive electrode terminal (corresponding one of 27) of the plurality of batteries 1 is connected to the positive electrode side module via the bus bar (positive electrode side lead) 56. It is connected to the terminal 51. Then, in the corresponding one (1γ) different from the battery (1δ) to which the bus bar 56 is connected among the plurality of batteries 1, the negative electrode terminal (corresponding one of 27) is the bus bar (negative electrode side lead). It is connected to the module terminal 52 on the negative electrode side via 57.

The battery pack 70 is provided with the printed wiring board 71 described above. A protection circuit 72, a thermistor 73 which is a temperature detector, and an external terminal 75 for energization are mounted on the printed wiring board 71. In the battery pack 70, an insulating member (not shown) prevents unnecessary connection between the electric path on the printed wiring board 84 and the wiring of the battery module 40. The module terminal 51 on the positive electrode side is connected to the protection circuit 72 via the wiring 76 or the like formed on the printed wiring board 71, and the module terminal 52 on the negative electrode side connects the wiring 77 or the like formed on the printed wiring board 71. It is connected to the protection circuit 72 via.

The thermistor 73, which is a temperature detector, detects the temperature of each of the plurality of batteries 1 forming the battery module 40. Then, the thermistor 73 outputs a detection signal about the temperature to the protection circuit 72.

The battery pack 70 has a current detection function and a voltage detection function. In the battery pack 70, the input current to the battery module 40 and the output current from the battery module 40 may be detected, and the current flowing through any of the plurality of batteries 1 forming the battery module 40 is detected. May be good. Further, in the battery pack 70, the respective voltages of the batteries 1 may be detected in the battery module 40, or the voltage applied to the entire battery module 40 may be detected. In the battery pack 70, the battery module 40 and the protection circuit 72 are connected via the wiring 74. A detection signal for current and a detection signal for voltage are output to the protection circuit 72 via the wiring 74.

In a certain embodiment, instead of detecting the respective voltages of the batteries 1, the positive electrode potential or the negative electrode potential is detected for each of the batteries 1 forming the battery module 40. In this case, the battery module 40 is provided with a lithium electrode or the like as a reference electrode. Then, each positive electrode potential or negative electrode potential of the battery 1 is detected with reference to the potential at the reference electrode.

The external terminal 75 is connected to an external device of the battery pack 70. The external terminal 75 is used for outputting the current from the battery module 40 to the outside and / or inputting the current to the battery module 40. When the battery module 40 of the battery pack 70 is used as a power source, an electric current is supplied to the outside of the battery pack 70 through an external terminal 75 for energization. Further, when charging the battery module 40, the charging current is supplied to the battery module 40 through the external terminal 75 for energization. The charging current of the battery module 40 includes, for example, regenerative energy for power of an automobile or the like. Further, the protection circuit 72 can be connected to the external terminal 75 via the positive wiring 78 and the negative wiring 79.

The protection circuit 72 has a function of being able to cut off the electrical connection between the battery module 40 and the external terminal 75. The protection circuit 72 is provided with a relay, a fuse, or the like as a connection cutoff portion. Further, the protection circuit 72 has a function of controlling charging / discharging of the battery module 40. The protection circuit 72 controls charging / discharging of the battery module 40 based on the detection result regarding any of the above-mentioned current, voltage, temperature, and the like.

For example, when the detection temperature of the thermistor 73 exceeds a predetermined temperature, the protection circuit 72 determines that the predetermined condition has been met. Further, when any of overcharge, overdischarge, overcurrent, etc. is detected in the battery module 40, the protection circuit 72 determines that the battery module 40 has met the predetermined conditions. Then, when it is determined that the battery module 40 meets the above-mentioned predetermined conditions, the protection circuit 72 can cut off the continuity between the protection circuit 72 and the external terminal 75 for energization. By cutting off the continuity between the protection circuit 72 and the external terminal 75 for energization, the output of the current from the battery module 40 to the outside and the input of the current to the battery module 40 are stopped. As a result, the continuous generation of overcurrent or the like in the battery module 40 is effectively prevented.

In a certain embodiment, a circuit formed in a device that uses the battery pack 70 (battery module 40) as a power source may be used as a protection circuit. Further, in the battery pack 70, a plurality of battery modules 40 may be provided, and the battery modules 40 may be electrically connected in series and / or in parallel.

[Use of battery pack]
The configuration of the battery pack 70 including the battery module 40 described above is appropriately changed depending on the application. The battery pack 70 is preferably used in a device or the like that is required to be charged and discharged with a large current. Specific uses of the battery pack 70 include a power source for a digital camera, a vehicle-mounted power source for a vehicle, and a stationary power source. In this case, examples of the vehicle on which the battery pack 70 including the battery module 40 is mounted include a two-wheel to four-wheel hybrid electric vehicle, a two-wheel to four-wheel electric vehicle, an assisted bicycle, and a railroad vehicle.

As described above, the battery pack 70 including the battery module 40 of the above-described embodiment has a high volume energy density. Therefore, the battery pack 70 (battery module 40) is preferably used as a starter power source for vehicles as an alternative power source for lead batteries, and is also suitable as an in-vehicle power source mounted on a hybrid vehicle and a stationary power source. Is.

FIG. 17 shows an application example to the vehicle 80 as an application example of the battery pack 70 described above. In the example shown in FIG. 17, the vehicle 80 includes a vehicle body 81 and a battery pack 70. In the example shown in FIG. 17, the vehicle 80 is a four-wheeled vehicle. The vehicle 80 may be equipped with a plurality of battery packs 70.

In the example of FIG. 17, the battery pack 70 is mounted in the engine room located in front of the vehicle body 81. The battery pack 70 may be mounted, for example, behind the vehicle body 81 or under the seat. In particular, the battery pack 70 including the battery module 40 described above can be arranged even in a narrow space under the seat. As described above, the battery pack 70 can be used as a power source for the vehicle 80. Further, the battery pack 70 can recover the regenerative energy of the power of the vehicle 80.

According to at least one of these embodiments or embodiments, each of the plurality of batteries is arranged in a state in which the vertical direction is along the arrangement direction. The plurality of batteries include a first battery whose bottom wall faces the installation surface of the base plate and a second battery whose second exterior member faces the installation surface of the base plate, and is a battery array. Then, the first battery and the second battery are arranged next to each other. As a result, it is possible to provide a battery module in which the heat generated in each of the batteries is appropriately dissipated and the volumetric energy density is high.

Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are also included in the scope of the invention described in the claims and the equivalent scope thereof.

Claims (15)

1. A battery array having a plurality of batteries arranged in the array direction,
   A base plate having an installation surface on which the battery array is installed, and
   Equipped with
   Each of the plurality of batteries includes an electrode group including a positive electrode and a negative electrode, and an exterior portion formed of metal and defining an internal cavity in which the electrode group is housed.
   Each of the exterior parts of the plurality of batteries includes a bottom wall, a peripheral wall surrounding the outer peripheral side of the internal cavity, and a flange protruding from an end portion of the peripheral wall opposite to the bottom wall to the outer peripheral side. A first exterior member including the above, and a second exterior member attached to the flange from the side opposite to the bottom wall in the height direction.
   In each of the exterior portion and the internal cavity of each of the plurality of batteries, the dimensions in the height direction are smaller than the dimensions in the vertical direction intersecting the height directions, and the dimensions in the vertical direction are smaller. The dimension of the above is smaller than the dimension in the lateral direction intersecting both the height direction and the vertical direction.
   Each of the plurality of batteries is arranged so that the vertical direction is along the arrangement direction.
   The plurality of batteries include a first battery in which the bottom wall faces the installation surface of the base plate, and a second battery in which the second exterior member faces the installation surface of the base plate. Prepare,
   In the battery array, the first battery and the second battery are arranged next to each other.
   Battery module.
2. The peripheral wall of the first exterior member includes a pair of first side walls facing each other across the internal cavity in the vertical direction, and a pair of second side walls facing each other across the internal cavity in the horizontal direction. With
   In the battery array, each of the batteries faces each of the adjacent batteries with the corresponding one of the first side walls facing each other.
   The battery module of claim 1.
3. Each of the plurality of batteries includes a pair of electrode terminals attached to the outer surface of the exterior portion.
   In each of the plurality of batteries, the electrode group is arranged between the pair of the electrode terminals in the lateral direction, and each of the pair of electrode terminals corresponds to the pair of the second side walls in the circumferential direction. One is placed in the extended range,
   The battery module of claim 2.
4. Further comprising a bus bar in the battery array that electrically connects two or more of the plurality of batteries.
   In each of the two or more batteries electrically connected by the bus bar, the bus bar comes into contact with one of the corresponding target terminals of the pair of electrode terminals.
   The bus bar extends between the two or more target terminals along the array direction of the batteries.
   The battery module of claim 3.
5. In each of the plurality of batteries, the area of each outer surface of the bottom wall and the second exterior member is larger than the area of each outer surface of the pair of first side walls, and the pair of said batteries. The battery module according to any one of claims 2 to 4, wherein the area of each of the outer surfaces of the first side wall is larger than the area of each outer surface of the pair of the second side walls.
6. A claim that, in each of the plurality of batteries, the lateral dimension of each of the pair of first sidewalls is larger than the longitudinal dimension of each of the pair of second sidewalls. The battery module according to any one of 2 to 5.
7. The battery array includes an insulating member having electrical insulation.
   In the battery array, each of the batteries sandwiches the insulating member with each of the adjacent batteries.
   The battery module according to any one of claims 1 to 6.
8. The insulating member is fixed to the base plate and
   Each of the plurality of batteries is fixed to the insulating member in a state where the peripheral wall receives a pressing force inward in the vertical direction from each of the adjacent batteries, and is positioned with respect to the base plate.
   The battery module according to any one of claims 7.
9. In each of the plurality of batteries,
   The positive electrode of the electrode group includes a positive electrode current collector and a positive electrode active material-containing layer supported on the surface of the positive electrode current collector, and the positive electrode current collector includes the positive electrode active material-containing layer. An unsupported portion, provided with a positive electrode current collecting tab protruding from the negative electrode to one side in the lateral direction in the internal cavity.
   The negative electrode of the electrode group includes a negative electrode current collector and a negative electrode active material-containing layer supported on the surface of the negative electrode current collector, and the negative electrode current collector includes the negative electrode active material-containing layer. A negative electrode current collecting tab that is an unsupported portion and protrudes with respect to the positive electrode in the lateral direction opposite to the side on which the positive electrode current collecting tab protrudes is provided.
   The battery module according to any one of claims 1 to 8.
10. The base plate includes a base material formed of metal and an insulating layer having electrical insulating properties and formed on the surface of the base material.
    The installation surface of the base plate is formed from the insulating layer.
    The battery module according to any one of claims 1 to 9.
11. A plurality of the battery arrays are provided.
    The installation surface of the base plate includes a first installation surface and a second installation surface facing the side opposite to the first installation surface.
    The plurality of battery arrays include a first battery array installed on the first installation surface and a second battery array installed on the second installation surface.
    The battery module according to any one of claims 1 to 10.
12. The battery module according to claim 11, wherein the arrangement directions of the plurality of batteries in the first battery arrangement coincide with the arrangement directions of the plurality of batteries in the second battery arrangement.
13. A battery pack comprising the battery module according to any one of claims 1 to 12.
14. An external terminal that is electrically connected to the battery module,
    With protection circuit
    13. The battery pack according to claim 13.
15. A vehicle equipped with the battery pack of claim 13 or 14.

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