JP7124209B2 - Battery modules, battery packs and vehicles - Google Patents

Description

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 part having an internal cavity for housing the electrode group. In some batteries, an exterior portion is made of metal such as stainless steel, and the exterior portion is formed from two exterior members, ie, 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 protrudes outward from the end of the peripheral wall opposite to the bottom wall. In this battery, the second exterior member faces the flange from the side opposite the bottom wall and is welded to the flange. In the battery provided with the exterior part as described above, the dimension in the height direction between the bottom wall and the second exterior member is the dimension in the vertical direction intersecting the height direction, and the dimension in the height direction and The exterior part is formed in a flat shape, which is smaller than each dimension in the horizontal direction that intersects the vertical direction.

Further, as a battery module, there is a battery module in which a plurality of batteries each having the above-described flat-shaped exterior portion with a small height dimension is provided. In such a battery module, a plurality of batteries are electrically connected via bus bars or the like. Such a battery module is required to appropriately dissipate the heat generated in each battery. In addition, it is required to reduce the volume of the entire battery module and ensure a high volumetric energy density of the battery module.

Japanese Patent Application Laid-Open No. 2009-99445 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 the heat generated in each battery is appropriately dissipated and a high volumetric energy density is ensured, a battery pack comprising the battery module, and the battery pack. To provide a vehicle equipped with

According to embodiments, a battery module comprises a battery array and a base plate. The battery array includes a plurality of batteries arranged in the array 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 part of the plurality of batteries includes a first exterior member and a second exterior member, the first exterior member including a bottom wall, a peripheral wall surrounding the outer peripheral side of the internal cavity, and a bottom wall in the peripheral wall. and a flange projecting outwardly from the opposite end. The second exterior member is attached to the flange from the opposite side of the bottom wall in the height direction intersecting the bottom wall. In each of the exterior parts and internal cavities of the plurality of batteries, the dimension in the height direction is smaller than the dimension in the vertical direction intersecting the height direction, and the dimension in the vertical direction is smaller than the height. It is smaller than the dimension in the horizontal direction, which intersects both the direction and the vertical direction. Each of the plurality of batteries is arranged with its vertical direction along the arrangement direction. The plurality of batteries includes a first battery having a bottom wall facing the installation surface of the base plate and a second battery having a second exterior member facing the installation surface of the base plate. A first battery and a second battery are arranged side by side.

Moreover, according to the embodiment, a battery pack including the aforementioned battery module is provided.

Moreover, according to the embodiment, a vehicle including the aforementioned battery pack is provided.

1 is a perspective view schematically showing an example of a battery according to an embodiment; FIG. FIG. 2 is a perspective view schematically showing the battery of FIG. 1 disassembled for each member. 3 is a schematic diagram showing the configuration of the electrode group of the battery of FIG. 1. FIG. 4 is a schematic diagram showing an electrical connection configuration between an electrode group and one of a pair of electrode terminals in the battery of FIG. 1. FIG. FIG. 5 is a perspective view schematically showing an example of the battery module according to the embodiment with the cover omitted. 6 is a schematic perspective view of the battery module of FIG. 5 viewed from a different direction from FIG. 5. FIG. 7 is a perspective view schematically showing the battery module of FIG. 5 in a state 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. 5. FIG. FIG. 9 is a schematic diagram showing two adjacent batteries in the battery array of the battery module of FIG. 5 as viewed from one side in the second direction. 10 is a schematic perspective view of two adjacent batteries in the battery array of the battery module of FIG. 5, with the two batteries and the insulating members between the batteries separated from each other; FIG. . 11 is a perspective view schematically showing a single insulating member provided in the battery array body of the battery module of FIG. 5. FIG. 12 is a schematic diagram showing a structure for attaching an insulating member to a base plate in the battery module of FIG. 5. FIG. 13 is a schematic diagram showing a connection state of a bus bar to a target terminal of one battery in the battery module of FIG. 5. FIG. 14 is a cross-sectional view schematically showing the structure of the base plate of the battery module of FIG. 5. FIG. 15A and 15B are schematic diagrams for explaining 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 diagram showing an example of a battery pack using the battery module according to the embodiment. FIG. 17 is a schematic diagram illustrating an example of a vehicle using the battery pack according to the embodiment;

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

[battery]
First, a single battery used in a battery module will be described. FIG. 1 shows an example of a battery 1 according to an embodiment. Moreover, 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. Battery 1 is, for example, a secondary battery.

As shown in FIGS. 1 and 2 , the battery 1 has an exterior portion 3 . The exterior part 3 is made of metal such as stainless steel. Examples of metals other than stainless steel that form the exterior portion 3 include aluminum, aluminum alloys, iron, plated steel, and the like. An internal cavity 11 is formed inside the exterior part 3 . In the battery 1 and the exterior part 3, the vertical direction (direction indicated by arrows X1 and X2), the horizontal direction (direction indicated by arrows Y1 and Y2) intersecting (perpendicular or substantially perpendicular) to the longitudinal direction, and A height direction (direction indicated by arrow Z1 and arrow Z2) that intersects (perpendicular or nearly perpendicular) to both the longitudinal and lateral directions is defined.

The exterior part 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 this 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 (the arrow Z1 side) of the internal cavity 11 in the height direction. Moreover, the peripheral wall 4 extends along the circumferential direction of the exterior part 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.

In addition, the internal space of the first exterior member 5 forms at least a part of the internal cavity 11 of the exterior part 3 and opens toward the side opposite to the side where the bottom wall 7 is located. The edge of the opening of the internal space of the first exterior member 5 is formed at the end of the peripheral wall 4 opposite to the bottom wall 7 . Here, in the battery 1 and the exterior part 3, the direction along the opening edge of the internal space of the first exterior member 5 coincides 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 comprises two pairs of side walls 8,9. A pair of sidewalls (first sidewalls) 8 face each other in the vertical direction with an internal cavity 11 interposed therebetween. A pair of side walls (second side walls) 9 face each other across the internal cavity 11 in the lateral direction. Each of the side walls 8 extends continuously in the lateral direction between the side walls 9 . Moreover, each of the side walls 9 extends continuously in the vertical direction between the side walls 8 .

The first exterior member 5 has a flange 13 . The flange 13 protrudes outward from the end of the peripheral wall 4 (side walls 8 and 9 ) opposite to the bottom wall 7 . Therefore, the flange 13 protrudes outward from the peripheral wall 4 and is formed away from the bottom wall 7 in the height direction. The flange 13 is formed along the entire circumference of the exterior portion 3 in the circumferential direction, and protrudes outward along the entire circumference of the exterior portion 3 in the circumferential direction. Moreover, the flange 13 extends from the opening edge of the internal space of the first exterior member 5 toward the outer peripheral side.

In this embodiment, the second exterior member 6 is a substantially plate-shaped member, and is formed in a substantially rectangular shape, for example. The second exterior member 6 is attached to the flange 13 from the opposite side of the bottom wall 7 in the height direction of the battery 1 and faces the flange 13 from the opposite side of the bottom wall 7 . 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. For this reason, the bottom wall 7 of the first exterior member 5 faces the second exterior member 6 (top wall 15) across the internal cavity 11 in the height direction. Moreover, 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 protrudes outward from the peripheral wall 4 (side walls 8 and 9). The second exterior member 6 protrudes outward along the entire circumference of the exterior portion 3 in the circumferential direction. Further, in the present embodiment, the thickness direction of the plate-shaped second exterior member 6 matches or substantially matches the height direction of the battery 1 (the exterior portion 3).

The second exterior member 6 is welded to the flange 13 while being arranged on the opposite side of the flange 13 from the bottom wall 7 . At the welded portion, the flange 13 and the second exterior member 6 are hermetically 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 . Moreover, the welded portion of the flange 13 and the second exterior member 6 is continuously formed over the entire circumference in the circumferential direction. Therefore, the internal cavity of the exterior part 3 is closed and sealed. At 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 can be reduced and the airtightness between the flange 13 and the second exterior member 6 is high compared to laser welding or the like.

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

Further, in the present embodiment, the vertical dimension between the pair of side walls 8 is smaller than the horizontal dimension 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. In the battery 1, the dimension in the vertical direction is smaller than the dimension in the horizontal direction. Moreover, the projection dimension of the flange 13 and the second exterior member 6 from the peripheral wall 4 to the outer peripheral side is about 2 mm or more and 5 mm or less. In this embodiment, the flange 13 and the projecting end of the projecting portion of the second exterior member 6 form the outer peripheral edge E of the exterior portion 3 (battery 1 ).

Since the exterior part 3 (the exterior members 5 and 6) is configured as described above, the area of the outer surface of each of the bottom wall 7 and the second exterior member 6 (the top wall 15) is equal to that of the pair of side walls (the first side wall) 8 compared to the area of each outer surface. The outer surface area of each side wall 8 is larger than the outer surface area of each of the pair of side walls (second side walls) 9 . Moreover, the lateral dimension of each of the side walls 8 is larger than the dimension of each of the side walls 9 in the longitudinal direction.

An electrode group 10 is housed in an internal cavity 11 of the exterior part 3 . FIG. 3 is a diagram illustrating the configuration of the electrode group 10. As shown in FIG. 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 carried on the surface of the positive electrode current collector foil 21A. The positive current collector 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 current collector foil 21A. Examples of positive electrode active materials include, but are not limited to, oxides, sulfides, and polymers that can intercalate and deintercalate lithium. Moreover, from the viewpoint of obtaining a high positive electrode potential, it is preferable that the positive electrode active material is lithium-manganese composite oxide, lithium-nickel composite oxide, lithium-cobalt composite oxide, lithium iron phosphate, or the like.

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 carried on the surface of the negative electrode current collector foil 22A. The negative electrode collector 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. Examples of the negative electrode active material include, but are not limited to, metal oxides, metal sulfides, metal nitrides, and carbon materials that can occlude and release lithium ions. As the negative electrode active material, a material having a lithium ion absorption/discharge potential of 0.4 V or more relative to the metal lithium potential, that is, a lithium ion absorption/discharge 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 absorption/release potential, an alloy reaction between aluminum or an aluminum alloy and lithium is suppressed. Allows the use of aluminum alloys. Examples of the negative electrode active material having a lithium ion absorption/desorption potential of 0.4 V (vs. Li ⁺ /Li) or higher include titanium oxides, lithium-titanium composite oxides such as lithium titanate, tungsten oxides, and amorphous tin. oxides, niobium-titanium composite oxides, tin silicon oxides, silicon oxides, and the like, and it is particularly preferable to use lithium-titanium composite oxides as the negative electrode active material. Note that when a carbon material that absorbs and releases lithium ions is used as the negative electrode active material, a copper foil is preferably used as the negative electrode current collector foil 22A. The carbon material used as the negative electrode active material has a lithium ion absorption/discharge potential of about 0 V (vs. Li ⁺ /Li).

The aluminum alloy used for the positive electrode current collector foil 21A and the negative electrode current collector foil 22A desirably contains one or more elements selected from Mg, Ti, Zn, Mn, Fe, Cu and Si. The purity of aluminum and aluminum alloys can be 98 wt% or higher, preferably 99.99 wt% or higher. Also, pure aluminum with 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 current collector foil 21A, a positive current collector tab 21D is formed by one long side edge 21C and its vicinity. In the 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 collector tab 21D, the positive electrode active material containing layer 21B is not carried on the surface of the positive electrode current collector foil 21A. Accordingly, the positive electrode current collector foil 21A includes the positive electrode current collector tab 21D as a portion on which the positive electrode active material containing layer 21B is not supported. Further, in the negative electrode current collector foil 22A, a negative electrode current collector tab 22D is formed by one long side edge 22C and its vicinity. In the example of FIG. 3, the negative electrode current collecting tab 22D is formed over the entire length of the long edge 22C. In the negative electrode current collecting tab 22D, the negative electrode active material containing layer 22B is not carried on the surface of the negative electrode current collecting foil 22A. Therefore, the negative electrode current collecting foil 22A includes the 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 made 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 formed integrally with one of the positive electrode 21 and the negative electrode 22 . Also, the separators 23 and 25 may be made of an organic material, an inorganic material, or a mixture of an organic material and an inorganic material. Examples of organic materials forming the separators 23 and 25 include engineering plastics and super engineering plastics. Engineering plastics include polyamide, polyacetal, polybutylene terephthalate, polyethylene terephthalate, syndiotactic polystyrene, polycarbonate, polyamideimide, polyvinyl alcohol, polyvinylidene fluoride, and modified polyphenylene ether. Super engineering plastics include polyphenylene sulfide, polyetheretherketone, liquid crystal polymer, polyvinylidene fluoride, polytetrafluoroethylene (PTFE), polyethernitrile, polysulfone, polyacrylate, polyetherimide and thermoplastic polyimide. be done. Inorganic materials forming the separators 23 and 25 include oxides (eg, aluminum oxide, silicon dioxide, magnesium oxide, phosphorous oxide, calcium oxide, iron oxide, titanium oxide), nitrides (eg, boron nitride, 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, 25 are arranged around the winding axis B while the separators 23, 25 are sandwiched between the positive electrode active material-containing layer 21B and the negative electrode active material-containing layer 22B. is wound around in a flat shape. The positive electrode 21, the separator 23, the negative electrode 22, and the separator 25 are, for example, stacked in this order and wound. Further, in the electrode group 10, the positive electrode current collecting tab 21D of the positive electrode current collecting foil 21A protrudes to one side in the direction along the winding axis B with respect to the negative electrode 22 and the separators 23 and 25. As shown in FIG. 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, 25 in the direction along the winding axis B opposite to the side where the positive electrode current collecting tab 21D projects. do.

The electrode group 10 is arranged such that the winding axis B is parallel or substantially parallel to the lateral direction of the battery 1 . Therefore, in the internal cavity 11 of the exterior part 3, the positive electrode current collecting tab 21D protrudes to one side in the horizontal direction with respect to the negative electrode 22 and the separators 23, 25. As shown in FIG. The negative electrode current collecting tab 22D protrudes from the positive electrode 21 and the separators 23 and 25 in the lateral direction opposite to the side where the positive electrode current collecting tab 21D projects.

Moreover, the electrode group 10 does not need to have a wound 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 electrodes and the negative electrodes. Also in this case, in the electrode group 10, the positive electrode current collecting tab protrudes from the negative electrode to one side in the lateral direction of the battery 1 (the exterior portion 3). 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 in the opposite direction to the side where the positive electrode current collecting tab projects.

In one embodiment, the electrode assembly 10 is impregnated with an electrolyte (not shown) in the internal cavity 11 . As the electrolytic solution, a non-aqueous electrolytic solution is used, and for example, a non-aqueous electrolytic solution prepared by dissolving an electrolyte in an organic solvent is used. In this case, as the electrolyte dissolved in the organic solvent, lithium perchlorate (LiClO ₄ ), lithium hexafluorophosphate (LiPF ₆ ), lithium tetrafluoroborate (LiBF ₄ ), lithium arsenic hexafluoride (LiAsF ₆ ), lithium salts such as lithium trifluoromethanesulfonate (LiCF ₃ SO ₃ ) and lithium bistrifluoromethylsulfonylimide [LiN(CF ₃ SO ₂ ) ₂ ], and mixtures thereof. In addition, as an 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), 2-methyltetrahydrofuran (2MeTHF), and dioxolane (DOX); linear ethers such as dimethoxyethane (DME) and diethoxyethane (DEE); γ-butyrolactone (GBL), acetonitrile (AN) and sulfolane (SL). These organic solvents are used alone or as a mixed solvent.

In one embodiment, a non-aqueous gel electrolyte obtained by combining a non-aqueous electrolyte and a polymer material is used instead of the electrolyte. In this case, the electrolyte and organic solvent described above are used. Polymer materials include polyvinylidene fluoride (PVdF), polyacrylonitrile (PAN), and polyethylene oxide (PEO).

Also, in some embodiments, solid electrolytes such as polymer solid electrolytes and inorganic solid electrolytes are provided as non-aqueous electrolytes instead of electrolyte solutions. In this case, the electrode group 10 may not be provided with the separators 23 and 25 . In the electrode group 10 , a solid electrolyte is sandwiched between the positive electrode 21 and the negative electrode 22 instead of the separators 23 and 25 . Therefore, in this embodiment, the positive electrode 21 and the negative electrode 22 are electrically insulated by the solid electrolyte. Also, in some embodiments, an aqueous electrolyte containing an aqueous solvent may be used as the electrolyte instead of the non-aqueous electrolyte.

As shown in FIGS. 1 and 2, a pair of electrode terminals 27 are attached to the outer surface of the exterior part 3 . One of the electrode terminals 27 becomes the positive terminal of the battery 1 and the other of the electrode terminals 27 becomes the negative 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 inclined surface 26 is provided between a corresponding one of the side walls (second side walls) 9 and the bottom wall 7 . Each of the pair of inclined surfaces 26 extends continuously in the longitudinal direction between the side walls 8 . Therefore, each of the inclined surfaces 26 extends 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 inclined surface 26 is inclined with respect to the bottom wall 7 and the side walls 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 so as to be exposed to the outside. Therefore, each of the electrode terminals 27 is provided in a range in which one corresponding side wall (second side wall) 9 extends in the circumferential direction of the exterior portion 3 . 1 and 2, each of the electrode terminals 27 is arranged at one of the corresponding central positions or approximately central positions of the inclined surfaces 26 in the vertical direction. The electrode group 10 is arranged between the pair of electrode terminals 27 in the horizontal direction. Each of the electrode terminals 27 is made of a conductive material such as aluminum, copper, stainless steel, or the like.

A pair of insulating members 28 made of an electrically insulating material are provided on the outer surface of the first exterior member 5 . Each of the insulating members 28 is disposed on a corresponding one of the outer surfaces of the side walls 9 and a 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 positioned with respect to the exterior portion 3 (first exterior member 5). electrical isolation.

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 positive current collecting tabs 21D is connected to one of the electrode terminals 27 (positive terminal) via one or more positive leads including positive backup lead 31A, positive relay lead 32A and positive terminal lead 33A. electrically connected. The connection between the positive current collecting tab 21D and the positive lead, the connection between the positive leads, and the connection between the positive lead and the positive terminal are performed by welding such as ultrasonic welding. Here, the positive electrode lead is made of a conductive metal. In addition, the positive electrode terminal (corresponding one of 27), the positive current collecting tab 21D and the positive electrode lead are electrically insulated from the exterior part 3 (the exterior members 5 and 6) by an insulating member (not shown) or the like. .

Similarly, the negative electrode current collecting tabs 22D of the electrode group 10 are bundled by welding such as ultrasonic welding. Then, the bundle of negative electrode current collecting tabs 22D is connected to the corresponding one (negative terminal) of the electrode terminal 27 via one or more negative leads including the negative backup lead 31B, the negative relay lead 32B, the negative electrode terminal lead 33B, and the like. 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 made of a conductive metal. In addition, the negative electrode terminal (corresponding one of 27), the negative current collecting tab 22D and the negative electrode lead are electrically insulated from the exterior part 3 (the exterior members 5 and 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 horizontal 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, one corresponding one of the positive electrode current collecting tab 21D and the negative electrode current collecting tab 22D is disposed, and one corresponding one of the positive electrode lead and the negative electrode lead is disposed.

As described above, in each of the exterior part 3 and the internal cavity 11 of the battery 1, the dimension in the height direction is much smaller than the dimension in the vertical direction, and the dimension in the vertical direction is larger than the dimension in the horizontal direction. smaller than the dimensions. 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 hardly come into contact with the side walls 8 . Therefore, gaps are likely to be formed between the electrode group 10 and each of the sidewalls (first sidewalls) 8 . Spaces are formed between the electrode group 10 and the side walls (second side walls) 9 as described above. In the battery 1, as described above, the outer surface areas of the bottom wall 7 and the second exterior member 6 (top wall 15) are compared to the outer surface areas of the side walls 8 and 9 by big. Due to the configuration as described above, in the battery 1, the heat dissipation from the bottom wall 7 and the top wall 15 to the outside is higher than the heat dissipation from the side walls 8 and 9 to the outside.

Moreover, the 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. Moreover, the battery 1 (exterior part 3) has a large dimension in the lateral direction and a small dimension in the height direction. Therefore, the battery 1 tends to bend in a state where the amount of bending in the height direction changes along the lateral direction.

It should be noted that in some modifications, a plurality of electrode groups may be housed in the internal cavity 11 . In another modification, the second exterior member (lid member) 6 is not plate-shaped, but is formed in a substantially rectangular parallelepiped shape with one side open, like the first exterior member 5 . In this case, the second armor member 6 comprises, in addition to the top wall 15 , a peripheral wall and a flange like the first armor member 5 . Then, the flange 13 of the first exterior member 5 and the flange of the second exterior member 6 are hermetically welded. However, in any of the modifications, the battery 1 (exterior part 3) is formed in a flat shape in which the dimension in the height direction is smaller than the dimension in the vertical direction and the dimension in the horizontal direction. In either case, the dimension in the height direction between the bottom wall 7 and the second exterior member 6 (top wall 15) in the internal cavity 11 is equal to that of the pair of side walls (first side walls) 8. The vertical dimension is smaller than the dimension between the pair of side walls (second side walls) 9 in the horizontal direction.

[Battery module]
Next, the battery module will be explained. The battery module according to the embodiment includes a plurality of flat-shaped batteries 1 having a small size 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. As shown in FIGS. In embodiments such as FIG. 5, two battery arrays 41A and 41B are provided. Here, in the battery module 40, the first direction (the directions indicated by arrows X3 and X4) and the second direction (perpendicular or substantially perpendicular) intersecting (perpendicular to) the first direction (as indicated by arrows Y3 and Y4) ), and a third direction (perpendicular or nearly perpendicular) to both the first and second directions (perpendicular or nearly perpendicular), indicated by arrows Z3 and Z4. 5 and 6 show the battery module 40 with the covers 61A and 61B, which will be described later, omitted. 5 and 6 are viewed from different directions with respect to 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, a battery array (first battery array) 41A is installed on the installation surface 45, and a battery array (second battery array) 41B is installed on the installation surface . Therefore, a base plate 42 is interposed between the battery arrays 41A and 41B. Also, the base plate 42 is arranged in a state in which the thickness direction coincides or substantially coincides with the third direction.

In each of the battery array bodies 41A and 41B, a plurality of batteries 1 are arrayed along the array direction. In embodiments such as FIG. 5, five batteries 1 are arranged in each of the battery array bodies 41A and 41B. The array direction of the batteries 1 in each of the battery array bodies 41A and 41B matches or substantially matches the first direction. In addition, in the embodiment shown in FIG. 5, etc., the arrangement direction of the batteries 1 in the battery array (first battery array) 41A is the same as the arrangement direction of the batteries 1 in the battery array (second battery array) 41B. , match or substantially match. In each of the battery arrays 41A and 41B, the vertical direction of each battery 1 matches or substantially matches the array direction (first direction) and the horizontal direction matches or substantially matches the second direction. is placed. That is, each of the batteries 1 is arranged with the vertical direction along the arrangement direction. Therefore, in each of the battery arrays 41A and 41B, each of the batteries 1 is arranged such that the height direction coincides 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 array bodies 41A and 41B, the plurality of batteries 1 are arranged in the second direction (the lateral direction of each battery 1) with no or almost no displacement with respect to each other. . In each of the battery array bodies 41A and 41B, the plurality of batteries 1 are arranged in the third direction (the height direction of each battery 1) with no or almost no displacement with respect to each other. be.

As shown in FIG. 7 and the like, the battery arrays 41A, 41B and the base plate 42 are accommodated inside the covers 61A, 61B and the like. Each of the covers 61A and 61B is made of resin, for example, 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 with one side open. The cover 61A covers the battery array 41A from one side in the third direction. Also, the cover 61B covers the battery array 41B from the side opposite to the cover 61A in the third direction.

A plurality of engagement grooves 65 recessed inward are formed in the outer edge of the base plate 42 . A plurality of engaging claws 66A are provided at the opening edge of the cover 61A, and a plurality of engaging claws 66B are provided at the opening edge of the cover 61B. Each of the engaging claws 66A, 66B engages with a corresponding one of the engaging grooves 65. As shown in FIG. Thereby, each of the covers 61A and 61B is fixed to the base plate 42 . One or more engagement pieces 67A are provided at the opening edge of the cover 61A, and one or more engagement pieces 67B are provided at the opening edge of the cover 61B. Each of the engaging pieces 67A engages with a corresponding one of the engaging pieces 67B in a range where the base plate 42 is not extended. The covers 61A, 61B are thereby fixed with respect to each other.

8 to 10 show two batteries 1 adjacent to each other in the array direction in the battery array 41A (41B). Here, FIG. 8 shows a perspective view, and FIG. 9 shows a state viewed from one side in the second direction (lateral direction of each battery). As shown in FIGS. 8 to 10 and the like, each of the battery arrays 41A and 41B includes an insulating member 43. As shown in FIGS. The insulating member 43 is made of resin or the like and has electrical insulation. In each of the battery arrays 41A and 41B, each of the batteries 1 sandwiches the insulating member 43 between each of the batteries 1 adjacent in the array direction. Therefore, the insulating member 43 is interposed between two batteries 1 adjacent in the arrangement direction. It should be noted that FIG. 10 shows a state in which two adjacent batteries 1 and the insulating member 43 between these batteries 1 are separated from each other. In addition, 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 for each of the battery arrays 41A and 41B.

As described above, each of the batteries 1 is arranged with the vertical direction along the arrangement direction. Therefore, in each of the batteries 1 of the battery arrays 41A and 41B, one of the pair of sidewalls (first sidewalls) 8 corresponding to each of the batteries 1 adjacent in the array direction is provided with the insulating member 43. facing each other across the Here, the batteries 1α and 1γ arranged at both ends in the array direction of the battery array 41A are defined, and the batteries 1β and 1δ arranged at both ends in the array direction of the battery array 41B are defined. Each of the batteries 1α, 1β, 1γ, and 1δ is adjacent to another battery 1 only on one side in the arrangement direction. 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 battery 1, one or two batteries 1 are adjacent in the arrangement direction.

Also, 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 installation surfaces 45 and 46 of the base plate 42 . In the second battery 1B, the second exterior member 6 (the top wall 15) faces one of the installation surfaces 45 and 46 of the base plate 42 corresponding thereto. In each of the battery arrays 41A and 41B, the first batteries 1A and the second batteries 1B are alternately arranged in the arrangement direction. Therefore, the first battery 1A and the second battery 1B are arranged adjacent to each other in the arrangement direction. 5 and other embodiments, the plurality of batteries 1 in each of the battery arrays 41A and 41B includes two first batteries 1A and three second batteries 1B. All of the batteries 1α, 1β, 1γ, and 1δ become the first battery 1A.

11 shows the insulating member 43 alone, and FIG. 12 shows the mounting structure of the insulating member 43 to the base plate 42. As shown in FIG. 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 such that the longitudinal direction coincides or substantially coincides with the second direction. Therefore, in each of the battery arrays 41A and 41B, each insulating member 43 is arranged with its longitudinal direction aligned with the lateral direction of each battery 1 . It should be noted that the dimension of each insulating member 43 in the longitudinal direction is the same or substantially the same as the dimension of each side wall (first side wall) 8 in the lateral direction of the battery 1 .

In each of the batteries 1 of the battery array bodies 41A and 41B, the peripheral wall 4 abuts on each of the insulating members 43 adjacent in the array direction. In each battery 1 , one corresponding side wall (first side wall) 8 abuts on each adjacent insulating member 43 , and one corresponding side wall 8 is bonded by adhesion or the like. Thereby, each battery 1 (exterior part 3 ) is fixed to each adjacent insulating member 43 . In each of the batteries 1 , one side wall 8 abuts on each of the adjacent insulating members 43 over the entire length or substantially the entire length in the lateral direction. Moreover, each of the batteries 1 is fixed to each of the adjacent insulating members 43 in a state of being pressed inward in the vertical direction from each of the adjacent batteries 1 .

Also, one or more engaging projections 62 are provided on each of the insulating members 43 . In embodiments such as FIG. 11 , each of the insulating members 43 is provided with two engaging projections 62 . Further, as shown in FIG. 12 and the like, a plurality of engaging holes 63 are formed in the mounting 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 a corresponding one of the engaging holes 63. As shown in FIG. 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 one of the corresponding engaging holes 63. be done. Each insulating member 43 is fixed to the installation surface 45 by adhesion or the like while being positioned with respect to the installation surface 45 . Further, each of the insulating members 43 is fixed to the installation surface 45 while being in surface contact with the installation surface 45 .

A plurality of engagement holes similar to the engagement holes 63 are also formed in the installation surface 46 of the base plate 42 . 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 mounting surface 46 of the base plate 42 in the same manner as the insulating members 43 of the battery array 41A. be. Each of the insulating members 43 is fixed to the installation surface 46 by adhesion or the like while being positioned with respect to the installation surface 46 . Further, each of the insulating members 43 is fixed to the installation surface 46 while being in surface contact with the installation surface 46 .

Also, 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, by positioning the insulating member 43 with respect to the installation surface 46 as described above, each of the batteries 1 is also positioned relative to the installation surface 46 in the first direction and the second direction. position. By positioning each of the batteries 1 with respect to the base plate 42 , each pair of electrode terminals 27 of the batteries 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 the bottom wall 7 of each of the first batteries 1A is in surface contact with one of the installation surfaces 45 and 46 corresponding thereto. Each of the first batteries 1A is fixed to one of the installation surfaces 45 and 46 by adhesion or the like in a state in which the outer surface of the bottom wall 7 is in surface contact with the corresponding one of the installation surfaces 45 and 46. . Also, in each of the battery arrays 41A and 41B, the outer surface of the second exterior member 6 (top wall 15) of each of the second batteries 1B is in surface contact with one of the installation surfaces 45 and 46 corresponding thereto. Each of the second batteries 1B is attached to one of the installation surfaces 45 and 46 by bonding or the like while the outer surface of the second exterior member 6 is in surface contact with one of the installation surfaces 45 and 46. Fixed.

Moreover, the battery module 40 of the embodiment shown in FIG. Each of bus bars 53, 55-57 is made of a conductive material such as metal.

In the embodiment shown in FIG. 5 and the like, each bus bar 53 electrically connects two batteries 1 adjacent in the array direction in each of the battery arrays 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 contacts a 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 groups 10 of the batteries 1 in the lateral direction of the batteries 1 . The bus bar 53 relays between target terminals (first target terminals) of the two batteries 1 . In each of the battery arrays 41A and 41B, the bus bar 53 is arranged between the target terminals of the two batteries 1 along the array direction (the first direction of the battery module 40), that is, each of the batteries 1 It extends 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 is in 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. be. The target terminals of three or more batteries 1 are arranged on the same side in the second direction with respect to the central position of the battery module 40 (the electrode groups 10 of each battery 1). In each of the battery array bodies 41A and 41B, the bus bar 53 extends along the array direction, that is, along the longitudinal direction of each battery 1, between target terminals of three or more batteries 1. be done.

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

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

Module terminals 51 and 52 are provided in the battery module 40 of the embodiment shown in FIG. 5 and the like. 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 with no or little displacement with respect to each other in the first direction and the second direction. The module terminals 51, 52 are positioned on the same side with respect to the battery arrays 41A, 41B in the first direction. Also, the module terminals 51 and 52 are arranged apart from each other in the second direction. The module terminal 52 is arranged on the opposite side of the module terminal 51 with respect to the central position of the battery module 40 in the second direction. Also, each electrode group 10 of the battery 1 is positioned between the module terminals 51 and 52 in the second direction.

In the battery array body 41A, the battery 1γ is arranged at the end closer to the module terminals 51 and 52 in the first direction (arrangement direction), and the battery 1γ is arranged at the end farther from the module terminals 51 and 52 in the first direction. 1α is placed. In the battery array body 41B, the battery 1δ is arranged at the end closer to the module terminals 51 and 52 in the first direction (arrangement direction), and the end farther from the module terminals 51 and 52 in the first direction. The battery 1β is placed in the .

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

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

In the battery 1α, a bus bar (second bus bar) 55 contacts one of the pair of electrode terminals 27 to which the bus bar 53 is not connected. Then, the bus bar 55 is connected to a corresponding one of the electrode terminals 27 of the battery 1α, which is a target terminal. In the battery 1β, the busbar 55 is in contact with one of the pair of electrode terminals 27 to which the busbar 53 is not connected. Then, the bus bar 55 is connected to a corresponding one of the electrode terminals 27 of the battery 1β, which is a target terminal. Therefore, 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, one of the pair of electrode terminals 27 The bus bar 55 is in contact with the target terminal (second target terminal). Thereby, the battery arrays 41A and 41B are electrically connected by the bus bar 55. As shown in FIG.

The target terminals of the two batteries 1α and 1β connected by the busbar 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 electrode groups 10 of the batteries 1α and 1β in the lateral direction of the batteries 1α and 1β. The bus bar 55 relays between target terminals (second target terminals) of the two batteries 1α and 1β. The bus bar 55 extends along the third direction between the target terminals of the two batteries 1α and 1β. That is, bus bar 55 extends along a direction intersecting the direction in which batteries 1 are arranged in battery arrays 41A and 41B (the first direction of battery modules 40). The bus bar 55 extends across the base plate 42 (beyond the base plate 42) between the target terminals (second target terminals) of the two batteries 1α and 1β.

In this embodiment, each of the bus bars 53, 55 to 57 electrically connects the plurality of batteries 1 as described above. 5 and other embodiments, a plurality (10) of batteries 1 forming battery arrays 41A and 41B are electrically connected in series between module terminals 51 and 52 by bus bars 53 and 55-57. be. In the battery module 40, the exterior parts 3 (the exterior members 5 and 6) of the batteries 1 do not come into contact with any of the bus bars 53 and 55-57.

Further, in the embodiment shown in FIG. 5 and the like, 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. Also, the printed wiring board 71 is positioned between the module terminals 51 and 52 in the second direction.

14 shows the configuration of the base plate 42. As shown in FIG. As shown in FIG. 14, the base plate 42 includes a plate-like base material 68 made of metal. In the battery module 40, the base material 68 is arranged such that the thickness direction coincides or substantially coincides with the third direction. Also, in the base plate 42 , insulating layers 69 are formed on both surfaces of the base material 68 . The insulating layer 69 is made of, for example, resin and has electrical insulating properties. An insulating layer 69 is formed over the entirety or substantially the entirety of both surfaces of the base material 68 . The insulating layer 69 is formed by vapor-depositing or coating an insulating material on the surface of the base material 68 . Alternatively, 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 of the insulating layer 69 . Therefore, each of the batteries 1 is adequately insulated with respect to the base material 68 .

15A and 15B are diagrams for explaining the installation of the battery array 41A on the installation surface 45 of the base plate 42. FIG. As shown in FIG. 15, when installing the battery array 41A, first, each of the insulating members 43 is placed on the installation surface 45 by engaging each of the engaging projections 62 with one of the corresponding engaging holes 63, for example. to be installed. At this time, each insulating member 43 is fixed to the installation surface 45 while being in surface contact with the installation surface 45 and positioned with respect to the base plate 42 in the first direction and the second direction. Then, each of the second batteries 1</b>B whose second exterior member 6 (top wall 15 ) faces the base plate 42 is attached to one or more corresponding insulating members 43 and the installation surface 45 . At this time, each of the second batteries 1B is positioned such that the outer surface of the second exterior member 6 is in surface contact with the mounting surface 45 and is positioned with respect to the base plate 42 in the first direction and the second direction. In this state, it is fixed to one or more corresponding insulating members 43 and the installation surface 45 .

Moreover, the plurality of insulating members 43 are fixed to the installation surface 45 in such a state that the spacing (pitch) in the first direction is slightly smaller than the dimension of the battery 1 in the vertical direction. That is, when the insulating member 43 is fixed to the installation surface 45 , the vertical dimension of the insulating member 43 in the first direction is greater than the vertical dimension between the outer surfaces of the pair of side walls 8 in each battery 1 . spacing is slightly reduced. Then, with the insulating member 43 and the second battery 1B attached to the mounting surface 45, each of the first batteries 1A whose bottom wall 7 faces the base plate 42 is attached to one or more corresponding insulating members 43. and attached to the installation surface 45 . At this time, each of the first batteries 1A is in a state in which the outer surface of the bottom wall 7 is in surface contact with the mounting surface 45 and positioned with respect to the base plate 42 in the first direction and the second direction. It is fixed to one or more corresponding insulating members 43 and to 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 dimension of each battery 1 in the longitudinal direction. Therefore, by attaching the first battery 1A to the installation surface 45, each of the batteries 1 receives an inward pressing force from each of the adjacent batteries 1 in the vertical direction. 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 arrays 41A and 41B of the battery module 40 of the above-described embodiment, each of the batteries 1 sandwiches the insulating member 43 between each of the batteries 1 adjacent in the array direction. Therefore, it is effectively prevented that the batteries 1 adjacent to each other are electrically connected through anything other than the bus bar 53 . This effectively prevents occurrence of a short circuit or the like in each of the battery arrays 41A and 41B.

Further, in the above-described embodiments 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 of the insulating layer 69 . Therefore, occurrence of a short circuit or the like is more effectively prevented in each of the battery arrays 41A and 41B. In addition, a short circuit between the battery arrays 41A and 41B via the base material 68 is effectively prevented. Therefore, in the battery module 40, an insulating structure is formed that effectively prevents short circuits and the like.

In addition, in each of the first batteries 1A, the second exterior member 6 (top wall 15) is located on the opposite side of the internal cavity 11 to the side on which the base plate 42 is located. The outer surface of 6 faces outward for the third direction. In each of the second batteries 1B, the bottom wall 7 is located on the opposite side of the internal cavity 11 to the side on which the base plate 42 is located, and the outer surface of the bottom wall 7 extends in the third direction. face outwards. As described above, each exterior part 3 of the battery 1 of the embodiment or the like is formed in a flat shape with a small dimension in the height direction. In each of the batteries 1 , the outer surface areas of the bottom wall 7 and the second exterior member 6 (top wall 15 ) are larger than the outer surface areas of the side walls 8 and 9 . Because of the configuration as described above, in each of the batteries 1, the heat dissipation from the bottom wall 7 and the top wall 15 to the outside is higher than the heat dissipation from the side walls 8 and 9 to the outside.

In the battery module 40 of the embodiment, each of the batteries 1 is arranged with the outer surface of the bottom wall 7 or the outer surface of the top wall 15 facing outward in the third direction. Therefore, in the battery module 40, heat generated in each battery 1 is radiated to the outside through the bottom wall 7 or the second exterior member 6 (top wall 15). In each of the batteries 1, heat is radiated to the outside through the bottom wall 7 or the second exterior member 6, which have high heat dissipation properties, so that the heat generated in the battery module 40 is properly radiated. Therefore, battery module 40 is appropriately cooled. In addition, since each of the batteries 1 is arranged with the outer surface of the bottom wall 7 or the outer surface of the top wall 15 facing outward in the third direction, it is easy to uniformly cool the entire battery module 40. becomes feasible.

In each of the battery arrays 41A and 41B, the first batteries 1A and the second batteries 1B are arranged side by side, and the first batteries 1A and the second batteries 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 protrude outward from the peripheral wall 4 . In the embodiment and the like, since the batteries 1 are arranged as described above, even if the batteries 1 configured as described above are used, each of the battery array bodies 41A and 41B can be reduced in size in the arrangement direction. be possible. As the dimensions of the battery arrays 41A and 41B in the array direction are reduced, the volumes of the battery arrays 41A and 41B are reduced. Thereby, a high volumetric energy density is ensured for each of the battery arrays 41A and 41B, and a high volumetric energy density for the battery module 40 is ensured.
In addition, since the battery 1 has a large dimension in the horizontal direction and a small dimension in the height direction, as described above, the bending amount in the height direction changes along the horizontal direction. easy. In each of the battery arrays 41A and 41B of the embodiment and the like, each of the batteries 1 is arranged with the vertical direction along the array direction. Then, in each of the batteries 1, one corresponding side wall 8 faces each adjacent battery 1 with the insulating member 43 interposed therebetween. side walls) 8 are joined. Since the battery arrays 41A and 41B are assembled as described above, the battery arrays 41A and 41B having high strength are formed. This suppresses deformation of the batteries 1 due to resonance or the like in each of the battery arrays 41A and 41B.

Moreover, in the battery module 40 , each of the batteries 1 is fixed to each of the adjacent insulating members 43 in a state in which each of the adjacent batteries 1 presses inward in the vertical direction. 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 . Thereby, the deformation of each battery 1 is more effectively suppressed. Furthermore, even if there are manufacturing tolerances in the batteries 1, the manufacturing tolerances can be absorbed by being compressed inwardly in the vertical direction from each of the adjacent batteries 1. FIG.
Also, when assembling the battery module 40, by fixing the batteries 1 with a two-liquid mixed adhesive that takes a long time to harden, the batteries 1 can be slid on the base plate 42 and placed in an appropriate position before it hardens. can be fixed to This not only makes assembly easier, but also makes the fixing position more precise.

Also, in each battery 1, one or more corresponding bus bars 53 extend between the peripheral wall 4 and the outer peripheral edge E of the exterior part 3 (battery 1). Therefore, in each of the battery arrays 41A and 41B, none of the bus bars 53 protrude outwardly (outwardly) in the second direction with respect to the outer peripheral edge E of the exterior portion 3 of each battery 1. . Since the busbars 53 in each of the battery arrays 41A and 41B are positioned on the inner peripheral side with respect to the outer peripheral ends E of the batteries 1, space loss is reduced in each of the battery arrays 41A and 41B. . Thereby, each of the battery arrays 41A and 41B can be further miniaturized, and the volume energy density of each of the battery arrays 41A and 41B can be further increased.

Note that in one modification, 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. Also in this modification, a plurality of batteries 1 are arranged in the battery array in the same manner as in the battery arrays 41A and 41B.

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

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

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

A thermistor 73 that is a temperature detector detects the temperature of each of the plurality of batteries 1 forming the battery module 40 . The thermistor 73 then outputs a temperature detection signal 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 one of the plurality of batteries 1 forming the battery module 40 is detected. good too. Also, in the battery pack 70 , the voltage of each battery 1 in the battery module 40 may be detected, or the voltage applied to the battery module 40 as a whole may be detected. In battery pack 70 , battery module 40 and protection circuit 72 are connected via wiring 74 . A current detection signal and a voltage detection signal are output to the protection circuit 72 via wiring 74 .

It should be noted that in one embodiment, instead of detecting the voltage of each of the batteries 1, the positive potential or the negative potential of each of the batteries 1 forming the battery module 40 is detected. 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 based on the potential at the reference electrode.

The external terminal 75 is connected to equipment outside the battery pack 70 . The external terminals 75 are used to output current from the battery module 40 to the outside and/or input current to the battery module 40 . When the battery module 40 of the battery pack 70 is used as a power source, current is supplied to the outside of the battery pack 70 through the external terminals 75 for conducting electricity. Also, when charging the battery module 40 , the charging current is supplied to the battery module 40 through the external terminals 75 for power supply. The charging current of the battery module 40 includes, for example, regenerative energy of motive power of an automobile or the like. Also, the protection circuit 72 can be connected to the external terminal 75 via a plus wiring 78 and a minus wiring 79 .

The protection circuit 72 has a function capable of interrupting 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 breaker. The protection circuit 72 also has a function of controlling charging and 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 one of the aforementioned current, voltage, temperature, and the like.

For example, when the temperature detected by the thermistor 73 exceeds a predetermined temperature, the protection circuit 72 determines that a predetermined condition has been met. Also, when any one of overcharge, overdischarge, overcurrent, or the like is detected in the battery module 40, the protection circuit 72 determines that the battery module 40 meets a predetermined condition. Then, when it is determined that the battery module 40 satisfies the above-described predetermined condition, the protection circuit 72 can cut off the electrical connection between the protection circuit 72 and the external terminal 75 for power supply. By interrupting the conduction between the protection circuit 72 and the external terminal 75 for conducting current, the current output from the battery module 40 to the outside and the current input to the battery module 40 are stopped. This effectively prevents overcurrent or the like from continuously occurring in the battery module 40 .

Note that in some embodiments, a circuit formed in a device that uses the battery pack 70 (battery module 40) as a power source may be used as the protection circuit. Also, 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.

[Battery pack applications]
The configuration and the like of the battery pack 70 including the battery modules 40 described above are appropriately changed depending on the application. The application of the battery pack 70 is preferably a device or the like that requires charging and discharging with a large current. Specific applications of the battery pack 70 include power supplies for digital cameras, on-board vehicles, stationary power supplies, and the like. In this case, vehicles in which the battery pack 70 including the battery module 40 is mounted include two- to four-wheeled hybrid electric vehicles, two- to four-wheeled electric vehicles, assisted bicycles, railway vehicles, and the like.

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

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

In one example of FIG. 17 , the battery pack 70 is mounted in the engine room located in front of the vehicle body 81 . Note that the battery pack 70 may be mounted, for example, in the rear of 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, battery pack 70 can be used as a power source for vehicle 80 . Also, the battery pack 70 can recover the regenerated energy of the power of the vehicle 80 .

According to at least one of these embodiments or examples, each of the plurality of batteries is arranged with its longitudinal direction along the arrangement direction. The plurality of batteries includes a first battery whose bottom wall faces the mounting surface of the base plate, and a second battery whose second exterior member faces the mounting surface of the base plate, and the battery array includes: , a first battery and a second battery are placed side by side. Accordingly, it is possible to provide a battery module in which the heat generated in each battery is appropriately radiated and a high volumetric energy density is ensured.

While several embodiments of the invention have been described, these embodiments have been presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the scope of the invention described in the claims and equivalents thereof.
Additional remarks are described below.
[1] A battery array comprising a plurality of batteries arranged in an array direction;
a base plate having an installation surface on which the battery array is installed;
and
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 accommodated,
The exterior part of each of the plurality of batteries includes a bottom wall, a peripheral wall surrounding the outer peripheral side of the internal cavity, a flange projecting from an end of the peripheral wall opposite to the bottom wall to the outer peripheral side, and a second exterior member attached to the flange from the opposite side of the bottom wall in the height direction,
In each of the exterior part and the internal cavity of each of the plurality of batteries, the dimension in the height direction is smaller than the dimension in the vertical direction intersecting the height direction, and the dimension in the vertical direction is smaller than the dimension in the vertical direction. is smaller than the dimension in the horizontal direction that intersects both the height direction and the vertical direction,
each of the plurality of batteries is arranged with the longitudinal direction along the arrangement direction,
The plurality of batteries includes 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. prepared,
In the battery array, the first battery and the second battery are arranged side by side,
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. a side wall;
In the battery array, each of the batteries has a corresponding one of the first sidewalls facing each of the adjacent batteries.
The battery module of [1].
[3] each of the plurality of batteries comprises a pair of electrode terminals attached to the outer surface of the exterior,
In each of the plurality of batteries, the electrode group is arranged between a pair of the electrode terminals in the lateral direction, and each of the pair of electrode terminals corresponds to a pair of the second side walls in the circumferential direction. placed in a range where one is extended,
The battery module of [2].
[4] further comprising a bus bar electrically connecting two or more of the plurality of batteries in the battery array;
In each of the two or more batteries electrically connected by the bus bar, the bus bar is in contact with a target terminal that is a corresponding one of the pair of electrode terminals,
The bus bar extends along the arrangement direction of the batteries between two or more of the target terminals.
The battery module of [3].
[5] In each of the plurality of batteries, the area of the outer surface of each of the bottom wall and the second exterior member is larger than the area of the outer surface of each of the pair of first side walls, Any one of [2] to [4], wherein the area of the outer surface of each of the pair of first side walls is larger than the area of the outer surface of each of the pair of second side walls. battery module.
[6] In each of the plurality of batteries, the dimension in the horizontal direction of each of the pair of first sidewalls is larger than the dimension in the vertical direction 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 between each of the adjacent batteries,
The battery module according to any one of [1] to [6].
[8] The insulating member is fixed to the base plate,
each of the plurality of batteries is fixed to the insulating member and positioned with respect to the base plate in a state in which the peripheral wall receives an inward pressing force in the longitudinal direction from each of the adjacent batteries;
The battery module of [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 a positive electrode current collecting tab that is an unsupported portion and protrudes toward 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. a negative electrode current collecting tab which is an unsupported portion and protrudes with respect to the positive electrode in the inner cavity in the lateral direction opposite to the side where the positive electrode current collecting tab projects;
The battery module according to any one of [1] to [8].
[10] The base plate includes a base material made of metal and an insulating layer having electrical insulation properties and formed on the surface of the base material,
The installation surface of the base plate is formed of the insulating layer,
The battery module according to any one of [1] to [9].
[11] comprising a plurality of the battery arrays,
the installation surface of the base plate includes a first installation surface and a second installation surface facing away from the first installation surface,
The plurality of battery arrays includes 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 [1] to [10].
[12] The battery module of [11], wherein the array direction of the plurality of batteries in the first battery array matches the array direction of the plurality of batteries in the second battery array.
[13] A battery pack comprising the battery module according to any one of [1] to [12].
[14] an external terminal electrically connected to the battery module;
a protection circuit;
The battery pack of [13], further comprising:
[15] A vehicle equipped with the battery pack of [13] or [14].

Claims (15)

a battery array including a plurality of batteries arranged in an array direction;
a base plate having an installation surface on which the battery array is installed;
and
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 accommodated,
The exterior part of each of the plurality of batteries includes a bottom wall, a peripheral wall surrounding the outer peripheral side of the internal cavity, a flange projecting from an end of the peripheral wall opposite to the bottom wall to the outer peripheral side, and a second exterior member attached to the flange from the opposite side of the bottom wall in the height direction intersecting the bottom wall,
In each of the exterior part and the internal cavity of each of the plurality of batteries, the dimension in the height direction is smaller than the dimension in the vertical direction intersecting the height direction, and the dimension in the vertical direction is smaller than the dimension in the vertical direction. is smaller than the dimension in the horizontal direction that intersects both the height direction and the vertical direction,
each of the plurality of batteries is arranged with the longitudinal direction along the arrangement direction,
The plurality of batteries includes 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. prepared,
In the battery array, the first battery and the second battery are arranged side by side,
battery module. The peripheral walls of the first exterior member include 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 has a corresponding one of the first sidewalls facing each of the adjacent batteries.
The battery module of claim 1. each of the plurality of batteries comprises a pair of electrode terminals attached to the outer surface of the exterior,
In each of the plurality of batteries, the electrode group is arranged between a pair of the electrode terminals in the lateral direction, and each of the pair of electrode terminals corresponds to a pair of the second side walls in the circumferential direction. placed in a range where one is extended,
The battery module of claim 2. further comprising a bus bar electrically connecting two or more of the plurality of batteries in the battery array;
In each of the two or more batteries electrically connected by the bus bar, the bus bar is in contact with a target terminal that is a corresponding one of the pair of electrode terminals,
The bus bar extends along the arrangement direction of the batteries between two or more of the target terminals.
The battery module according to claim 3. In each of the plurality of batteries, the area of the outer surface of each of the bottom wall and the second exterior member is larger than the area of the outer surface of each of the pair of first side walls, 5. The battery module of any one of claims 2 to 4, wherein the area of the outer surface of each of the first side walls is larger than the area of the outer surface of each of the pair of second side walls. In each of the plurality of batteries, the dimension in the horizontal direction of each of the pair of first sidewalls is larger than the dimension in the vertical direction of each of the pair of second sidewalls. 6. The battery module according to any one of 2 to 5. The battery array includes an insulating member having electrical insulation,
In the battery array, each of the batteries sandwiches the insulating member between each of the adjacent batteries,
The battery module according to any one of claims 1 to 6. The insulating member is fixed to the base plate,
each of the plurality of batteries is fixed to the insulating member and positioned with respect to the base plate in a state in which the peripheral wall receives an inward pressing force in the longitudinal direction from each of the adjacent batteries;
The battery module according to claim 7. 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 a positive electrode current collecting tab that is an unsupported portion and protrudes toward 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. a negative electrode current collecting tab which is an unsupported portion and protrudes with respect to the positive electrode in the inner cavity in the lateral direction opposite to the side where the positive electrode current collecting tab projects;
The battery module according to any one of claims 1 to 8. The base plate comprises a base material made of metal and an insulating layer having electrical insulation properties and formed on the surface of the base material,
The installation surface of the base plate is formed of the insulating layer,
The battery module according to any one of claims 1 to 9. comprising a plurality of the battery arrays,
The installation surface of the base plate includes a first installation surface and a second installation surface facing away from the first installation surface,
The plurality of battery arrays includes 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 of claim 11, wherein the array direction of the plurality of batteries in the first battery array matches the array direction of the plurality of batteries in the second battery array. A battery pack comprising the battery module according to any one of claims 1 to 12. an external terminal electrically connected to the battery module;
a protection circuit;
14. The battery pack of claim 13, further comprising: A vehicle comprising the battery pack according to claim 13 or 14.

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