Batteries and battery modules

Abstract

A battery according to an embodiment of the present invention comprises an exterior part, an electrode group, a terminal, and an insulator. The electrode group is housed in an internal cavity of the exterior part. The terminal is inserted into the internal cavity through the exterior part and is provided with a terminal head disposed outside the exterior part. The insulator is provided with a bottom part sandwiched between the terminal head and the outer surface of the exterior part, and a covering part covering the terminal head from the outer circumferential side of the terminal on the outer surface of the exterior part. The covering part abuts on the outer surface of the exterior part, and the projection height of the covering part from the outer surface of the exterior part is equal to or higher than the projection height of the terminal head from the outer surface of the exterior part over the entire circumference.

Description

[Technical Field]

[0001] FIELD OF THE INVENTION Embodiments of the present invention relate to batteries and battery modules. [Background technology]

[0002] Some batteries, such as lithium-ion secondary batteries, have an electrode group housed in the internal cavity of an exterior part. In such batteries, terminals (electrode terminals) are attached to the exterior part, and the terminals are electrically connected to the electrode group via leads or the like. In the battery, an electrical path from the electrode group is formed through the leads and terminals. Some batteries also have terminal heads as terminals. In batteries using terminals with terminal heads, the terminals penetrate the exterior part and are inserted into the internal cavity, and the terminal heads are positioned outside the exterior part.

[0003] When assembling a battery module in which multiple batteries are electrically connected using the above-mentioned batteries, bus bars are connected to the battery terminals, and the multiple batteries are electrically connected via the bus bars. Furthermore, during the battery module assembly process, measurements of the batteries that form the battery module are performed to confirm the dimensions of the assembled battery module. When assembling a battery module using batteries whose terminal heads are located outside the exterior, it is necessary to appropriately prevent unintentional contact of the terminal heads located outside the exterior with conductors, and to appropriately prevent short circuits caused by contact of the terminal heads with the conductors. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent No. 5941654 [Patent Document 2] Japanese Patent No. 5595830 Summary of the Invention [Problem to be solved by the invention]

[0005] The problem to be solved by the present invention is to provide a battery and a battery module including such a battery in which unintentional contact of a terminal head arranged on the outside of an exterior part with a conductor is appropriately prevented during work such as assembling the battery module. [Means for solving the problem]

[0006] According to an embodiment, a battery includes an exterior, an electrode group, a terminal, and an insulator, and the exterior has an internal cavity. The electrode group includes a positive electrode and a negative electrode and is housed in the internal cavity. The terminal is inserted into the internal cavity through the exterior and is electrically connected to the electrode group. The terminal includes a terminal head disposed on the exterior of the exterior. The insulator has a bottom sandwiched between the terminal head and the outer surface of the exterior, and a covering portion that covers the terminal head from the outer surface of the exterior from the outer periphery of the terminal, and has electrical insulation properties. The covering portion abuts against the outer surface of the exterior, and the height of the covering portion protruding from the outer surface of the exterior is equal to or greater than the height of the terminal head protruding from the outer surface of the exterior around the entire circumference. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a perspective view showing a battery according to a first embodiment. [Figure 2] FIG. 2 is a schematic diagram showing the battery according to the first embodiment as viewed from one side in the depth direction. [Figure 3] FIG. 3 is a plan view showing the battery according to the first embodiment as viewed from one side in the height direction. [Figure 4] FIG. 4 is a cross-sectional view showing the battery according to the first embodiment, taken along a cross section perpendicular or substantially perpendicular to the lateral direction. [Figure 5] FIG. 5 is a cross-sectional view showing one of a pair of terminals and the configuration in the vicinity thereof in the battery according to the first embodiment, taken along a cross section perpendicular or substantially perpendicular to the lateral direction of the battery. [Figure 6] FIG. 6 is a perspective view showing the battery module according to the first embodiment. [Figure 7] FIG. 7 is a cross-sectional view illustrating a configuration for connecting bus bars to battery terminals in the battery module according to the first embodiment. [Figure 8] FIG. 8 is a perspective view showing a battery module according to a first modified example. [Figure 9] FIG. 9 is a perspective view showing a battery module according to a second modified example. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments will be described with reference to the drawings.

[0009] (First embodiment) A first embodiment will be described below as an example of an embodiment. First, a battery 1, which is a single cell used in the first embodiment, will be described. FIGS. 1, 2, 3, and 4 show the battery 1 according to the first embodiment. As shown in FIGS. 1 to 4, the battery 1 includes an electrode group 2 and an exterior part 3. In the example shown in FIGS. 1 to 4, the exterior part 3 includes an exterior container 5 and a lid member 6. The exterior part 3 including the exterior container 5 and the lid member 6 is formed from a metal such as aluminum, an aluminum alloy, iron, copper, or stainless steel, and is electrically conductive.

[0010] 1 to 4, the battery 1 (exterior part 3) has a depth direction (the direction indicated by arrows X1 and X2), a lateral direction (the direction indicated by arrows Y1 and Y2) that intersects (is perpendicular or substantially perpendicular to) the depth direction, and a height direction (the direction indicated by arrows Z1 and Z2) that intersects (is perpendicular or substantially perpendicular to) both the depth direction and the lateral direction. For each of the battery 1 and the exterior part 3, the dimension in the depth direction is smaller than the dimension in the lateral direction and the dimension in the height direction. Note that FIG. 1 is a perspective view, and FIG. 2 is a view from one side in the depth direction. Furthermore, FIG. 3 is a view from one side in the height direction, and FIG. 4 shows a cross section perpendicular or substantially perpendicular to the lateral direction.

[0011] The outer container 5 includes a bottom wall 7 and a peripheral wall 8. An internal cavity 10 is formed inside the exterior part 3, and the internal cavity 10 is defined by the bottom wall 7 and the peripheral wall 8 of the outer container 5. In the outer container 5, the internal cavity 10 opens toward the side opposite the bottom wall 7 in the height direction. The peripheral wall 8 includes two pairs of side walls 11, 12. The pair of side walls 11 face each other in the horizontal direction, sandwiching the internal cavity 10 therebetween. The pair of side walls 12 face each other in the depth direction, sandwiching the internal cavity 10 therebetween. Each of the side walls 11 extends continuously between the side walls 12 in the depth direction. Each of the side walls 12 extends continuously between the side walls 11 in the horizontal direction. The cover member 6 is attached to the peripheral wall 8 at the end opposite the bottom wall 7. As a result, the cover member 6 closes the opening of the internal cavity 10. The cover member 6 and the bottom wall 7 face each other in the height direction, sandwiching the internal cavity 10. The cover member 6 is attached to the peripheral wall 8 by welding such as seam welding.

[0012] In the example shown in FIGS. 1 to 4 , the lid member 6 is attached to the peripheral wall 8 of the outer container 5 with the thickness direction of the lid member 6 coinciding or nearly coinciding with the height direction of the battery 1. The lid member 6 has a peripheral edge 14 that forms the edge of the outer surface. In the battery 1, the peripheral edge 14 is welded to the peripheral wall 8 of the outer container 5. The peripheral edge 14 has a pair of short edges 17 and a pair of long edges 18. The pair of short edges 17 are spaced apart from each other in the lateral direction of the battery 1, and each of the short edges 17 extends continuously between the pair of long edges 18 along the depth direction of the battery 1. The pair of long edges 18 are spaced apart from each other in the lateral direction of the battery 1, and each of the long edges 18 extends continuously between the pair of short edges 17 along the lateral direction of the battery 1. In the battery 1, each of the short edges 17 is welded to a corresponding one of the pair of side walls 11, and each of the long edges 18 is welded to a corresponding one of the pair of side walls 12. Furthermore, the dimension of the lid member 6 in the depth direction of the battery 1 (direction along the short edge 17) is smaller than the dimension of the lid member 6 in the width direction of the battery 1 (direction along the long edge 18).

[0013] The electrode group 2 is housed in the internal cavity 10. In FIG. 2, some of the components housed in the internal cavity 10, such as the electrode group 2, are indicated by dashed lines. The electrode group 2 includes a positive electrode 13A and a negative electrode 13B. In the electrode group 2, a separator (not shown) is interposed between the positive electrode 13A and the negative electrode 13B. The separator has electrical insulation properties and electrically insulates the positive electrode 13A from the negative electrode 13B.

[0014] The positive electrode 13A includes a positive electrode current collector such as a positive electrode current collector foil and a positive electrode active material-containing layer (not shown) supported on the surface of the positive electrode current collector. The positive electrode current collector is, but is not limited to, for example, an aluminum foil or an aluminum alloy foil, and has a thickness of approximately 10 μm to 20 μm. The positive electrode active material-containing layer includes a positive electrode active material and may optionally include a binder and a conductive agent. Examples of the positive electrode active material include, but are not limited to, oxides, sulfides, and polymers capable of absorbing and releasing lithium ions. The positive electrode current collector includes a positive electrode current collector tab 15A as a portion not supporting the positive electrode active material-containing layer.

[0015] The negative electrode 13B includes a negative electrode current collector such as a negative electrode current collector foil and a negative electrode active material-containing layer (not shown) supported on the surface of the negative electrode current collector. The negative electrode current collector is, but is not limited to, for example, aluminum foil, aluminum alloy foil, or copper foil, and has a thickness of approximately 10 μm to 20 μm. The negative electrode active material-containing layer includes a negative electrode active material and may optionally include a binder and a conductive agent. The negative electrode active material is, but is not limited to, metal oxides, metal sulfides, metal nitrides, and carbon materials capable of absorbing and releasing lithium ions. The negative electrode current collector includes a negative electrode current collector tab 15B as a portion not supporting the negative electrode active material-containing layer.

[0016] In the example electrode group 2 shown in FIGS. 2 and 3 , a positive electrode 13A, a negative electrode 13B, and a separator are wound with the separator sandwiched between the negative electrode active material-containing layer and the positive electrode active material-containing layer, forming a wound electrode group 2. In another example, the electrode group 2 has a stack structure in which multiple positive electrode plates that become the positive electrodes 13A and multiple negative electrode plates that become the negative electrodes 13B are alternately stacked, and a separator is provided between the positive electrode plates and the negative electrode plates. By forming the electrode group 2 as described above, a positive electrode current collecting tab 15A and a negative electrode current collecting tab 15B are formed as a pair of current collecting tabs 15 in the electrode group 2. The pair of current collecting tabs 15 do not contact each other and are electrically insulated from each other.

[0017] In the electrode group 2, each of the pair of current collecting tabs 15 protrudes relative to the positive electrode active material-containing layer, the negative electrode active material-containing layer, the separator, etc. In one example shown in FIGS. 2 and 3 , the pair of current collecting tabs 15 protrude in opposite directions. The electrode group 2 is disposed in the internal cavity 10 with the positive electrode current collecting tab 15A protruding toward one lateral side of the battery 1 and the negative electrode current collecting tab 15B protruding toward the lateral side of the battery 1 opposite the lateral side from the lateral side from which the positive electrode current collecting tab 15A protrudes. In one example of the electrode group 2, the pair of current collecting tabs 15 protrude toward the same side. In this case, the electrode group 2 is disposed in the internal cavity 10 with the pair of current collecting tabs 15 (positive electrode current collecting tab 15A and negative electrode current collecting tab 15B) protruding toward the side where the lid member 6 is located in the height direction of the battery 1. The pair of current collecting tabs 15 are disposed spaced apart from each other in the lateral direction of the battery 1.

[0018] In addition, in the internal cavity 10, the electrode group 2 is retained (impregnated) with an electrolytic solution (not shown). The electrolytic solution may be a nonaqueous electrolytic solution in which an electrolyte is dissolved in an organic solvent, or may be an aqueous electrolytic solution such as an aqueous solution. Instead of the electrolytic solution, a gel electrolyte or a solid electrolyte may be used. When a solid electrolyte is used as the electrolyte, the solid electrolyte is interposed between the positive electrode 13A and the negative electrode 13B in the electrode group, instead of a separator. In this case, the solid electrolyte electrically insulates the positive electrode 13A from the negative electrode 13B.

[0019] In the battery 1, a pair of terminals 16 are attached to the cover member 6 of the exterior casing 3. The terminals 16 are made of a conductive material such as metal. One of the pair of terminals 16 is the positive terminal 16A of the battery 1, and the other of the pair of terminals 16 is the negative terminal 16B of the battery 1. Each of the terminals 16 is attached to the cover member 6 with a portion located outside the exterior casing 3. Each of the terminals 16 penetrates the cover member 6 along the height direction of the battery 1 and is inserted into the internal cavity 10 through the cover member 6. The pair of terminals 16 are spaced apart from each other in the lateral direction of the battery 1. Figure 4 shows a cross section passing through one of the pair of terminals 16.

[0020] A pair of leads 20 are disposed in the internal cavity 10 of the exterior part 3. In FIG. 2 , the pair of leads 20 are indicated by dashed lines along with the electrode group 2. One of the pair of leads 20 is a positive electrode lead 20A, and the other of the pair of leads 20 is a negative electrode lead 20B. Each lead 20 is formed from a conductive material such as a metal. Examples of conductive materials for the leads 20 include aluminum, stainless steel, copper, and iron. The positive electrode lead 20A forms at least a portion of the electrical path between the positive electrode current collector tab 15A and the positive electrode terminal 16A, connecting the positive electrode 13A of the electrode group 2 to the positive electrode terminal 16A. This electrically connects the positive electrode terminal 16A to the positive electrode 13A of the electrode group 2. The negative electrode lead 20B forms at least a portion of the electrical path between the negative electrode current collector tab 15B and the negative electrode terminal 16B, connecting the negative electrode 13B of the electrode group 2 to the negative electrode terminal 16B. As a result, the negative electrode terminal 16B is electrically connected to the negative electrode 13B of the electrode group 2.

[0021] As described above, in the battery 1, each of the pair of current collecting tabs 15 is connected to a corresponding one of the pair of terminals 16 via a corresponding one of the pair of leads 20. The shape of each of the leads 20 is not limited to the shapes shown in FIGS. 2 and 4 . In the example shown in FIGS. 2 and 4 , each of the leads 20 has two legs. However, in one example, each of the leads 20 may have only one leg. Furthermore, in a configuration in which the pair of current collecting tabs 15 (positive electrode current collecting tab 15A and negative electrode current collecting tab 15B) in the electrode group 2 protrudes in the height direction toward the side where the lid member 6 is located, the shape of each of the leads 20 and the arrangement of each of the leads 20 in the internal cavity 10 differ from the configuration shown in FIGS. 2 and 4 . However, even in a configuration in which the pair of current collecting tabs 15 protrude in the height direction toward the side where the lid member 6 is located, each of the pair of current collecting tabs 15 is connected to a corresponding one of the pair of terminals 16 via a corresponding one of the pair of leads 20.

[0022] As shown in FIG. 4 and other figures, in the internal cavity 10, an electrode group presser 21, which serves as an internal insulator, is disposed between the electrode group 2 and the lid member 6 in the height direction of the battery 1. The electrode group presser 21 is disposed between each of the leads 20 and the lid member 6 in the height direction of the battery 1. The electrode group presser 21 is electrically insulating. The pair of current collecting tabs 15 and the pair of leads 20 are prevented from contacting the lid member 6 by the electrode group presser 21, and are electrically insulated from the lid member 6. In the internal cavity 10, each of the terminals 16 penetrates the electrode group presser 21 in the height direction of the battery 1 and is connected to a corresponding one of the leads 20 while also penetrating the electrode group presser 21.

[0023] Furthermore, a pair of insulating guards (not shown) are arranged as internal insulators in the internal cavity 10 of the exterior package 3. Each of the insulating guards has electrical insulation properties. Each of the pair of insulating guards prevents a corresponding one of the pair of current collecting tabs 15 and a corresponding one of the pair of leads 20 from contacting the exterior package 5. This electrically insulates the pair of current collecting tabs 15 and the pair of leads 20 from the exterior package 5. Therefore, the electrode group presser 21 and insulating guards, which serve as internal insulators, electrically insulate the pair of current collecting tabs 15 and the pair of leads 20 from the exterior package 3, which includes the exterior package 5 and the lid member 6.

[0024] 1 to 4, a gas release valve 22 and a liquid filling port (not shown) are formed in the lid member 6. A sealing plate 23 that closes the liquid filling port is welded to the outer surface of the lid member 6. The gas release valve 22 and the liquid filling port are disposed between the pair of terminals 16 in the lateral direction of the battery 1. Note that the battery 1 does not necessarily need to be provided with the gas release valve 22 and the liquid filling port.

[0025] Furthermore, in the battery 1, a pair of through holes 25 is formed in the lid member 6 of the exterior part 3. The pair of through holes 25 is formed in the lid member 6 so as to be spaced apart from each other in the lateral direction of the battery 1, and only one of the pair of through holes 25 is shown in FIG. 4 . Each of the through holes 25 penetrates the lid member 6 along the height direction of the battery 1, from the outer surface of the lid member 6 (the outer surface of the exterior part 3) to the internal cavity 10. Each of the pair of terminals 16 penetrates the lid member 6 through a corresponding one of the pair of through holes 25 and is inserted into the internal cavity 10 from that corresponding one of the through holes 25. The terminals 16 are attached to the lid member 6 at or near the corresponding one of the pair of through holes 25. One of the pair of through holes 25 into which the positive terminal 16A is inserted is the positive-side through hole, and the other of the pair of through holes 25 into which the negative terminal 16B is inserted is the negative-side through hole.

[0026] The battery 1 includes a pair of insulators 26 and a pair of gaskets 27. One insulator 26 and one gasket 27 are provided corresponding to the positive terminal 16A, and one is provided corresponding to the negative terminal 16B. Of the pair of insulators (terminal insulators) 26, one that corresponds to the positive terminal 16A is the positive-side insulator 26A, and one that corresponds to the negative terminal 16B is the negative-side insulator 26B. Of the pair of gaskets 27, one that corresponds to the positive terminal 16A is the positive-side gasket, and one that corresponds to the negative terminal 16B is the negative-side gasket. Note that only one of the pair of insulators 26 and one of the pair of gaskets 27 are shown in FIG. 4 .

[0027] Each of the insulators (terminal insulators) 26 has electrical insulation properties and is formed, for example, from an electrically insulating resin. Each of the gaskets 27 has electrical insulation properties and is formed, for example, from an electrically insulating resin. Each of the gaskets 27 is formed, for example, in a ring shape or a substantially ring shape. In this embodiment, each of the terminals 16 is prevented from contacting the cover member 6 by a corresponding one of the insulators 26 and a corresponding one of the gaskets 27 at the attachment portion of the exterior part 3 to the cover member 6, and is electrically insulated from the exterior part 3 including the cover member 6.

[0028] The following describes the configuration of one of the pair of terminals 16 and the portion where the terminal 16 is attached to the exterior part 3 (lid member 6). Figure 5 shows the configuration of one of the pair of terminals 16 and its vicinity. Figure 5 shows one of the pair of terminals 16 and its vicinity in the same cross section as Figure 4. Therefore, Figure 5 shows a cross section that is perpendicular or nearly perpendicular to the lateral direction of the battery 1 and passes through the terminal 16. The other of the pair of terminals 16 and the portion where the terminal 16 is attached to the exterior part 3 (lid member 6) also have the same configuration as described below. That is, the configuration of the other of the pair of terminals 16 and the insulator 26 and gasket 27 corresponding to that terminal 16 also have the same configuration as shown in Figure 5 and the like, and the same configuration as described below.

[0029] As shown in Figure 5 and other figures, the terminal 16 has a central axis C. In the terminal 16 and its mounting portion, the direction along the central axis C is defined as the axial direction, and the direction around the central axis C is defined as the circumferential direction. In the terminal 16 and its mounting portion, the direction perpendicular or nearly perpendicular to the central axis C is defined as the radial direction. In the terminal 16 and its mounting portion, the side away from the central axis C in the radial direction is the outer circumferential side, and the side toward the central axis C in the radial direction is the inner circumferential side.

[0030] The terminal 16 comprises a terminal shaft 31 and a terminal head 32. The terminal head 32 is located adjacent to one axial side of the terminal 16 relative to the terminal shaft 31 and protrudes radially outward relative to the terminal shaft 31. The terminal head 32 protrudes radially outward from the terminal shaft 31 around the entire circumferential direction of the terminal 16 (the direction around the central axis C). Therefore, the cross-sectional area of ​​the terminal head 32 in a cross section perpendicular or nearly perpendicular to the central axis C is larger than the cross-sectional area of ​​the terminal shaft 31 in a cross section perpendicular or nearly perpendicular to the central axis C. Furthermore, the terminal 16 has an end E1 on one axial side formed by the terminal shaft 31, and an end E2 on the opposite axial side from end E1 formed by the terminal head 32. The terminal 16 is attached to the cover member 6 with the central axis C aligned along the height direction of the battery 1, i.e., with the axial direction coinciding or nearly coinciding with the height direction of the battery 1.

[0031] The terminal shaft 31 of the terminal 16 is inserted into the internal cavity 10 through the through hole 25 of the lid member 6. That is, the terminal shaft 31 of the positive terminal 16A is inserted into the internal cavity 10 through the positive electrode side through hole, and the terminal shaft 31 of the negative terminal 16B is inserted into the internal cavity 10 through the negative electrode side through hole. In the internal cavity 10, the terminal shaft 31 of the terminal 16 passes through the electrode group presser 21. In the internal cavity 10, the terminal shaft 31 of the terminal 16 is connected to the lead 20 (the corresponding one of the positive electrode side lead 20A and the negative electrode side lead 20B) between the electrode group 2 and the electrode group presser 21 in the height direction of the battery 1.

[0032] The terminal head 32 of the terminal 16 is disposed outside the exterior part 3. In the example shown in FIGS. 1 to 5, the terminal head 32 is disposed outside the exterior part 3 in a state where it protrudes from the outer surface of the cover member 6. As shown in FIG. 5 and other figures, the terminal head 32 of the terminal 16 has head end faces 33, 35. In the terminal 16, the end E2 is formed by the head end face (first head end face) 33, which is the head upper end face, and in the terminal head 32, the end farther from the terminal shaft 31 in the axial direction is formed by the head end face 33. In the terminal head 32 of the terminal 16, the end closer to the terminal shaft 31 in the axial direction is formed by the head end face (second head end face) 35, which is the head lower end face, and the head end face 35 is located at the boundary with the terminal shaft 31.

[0033] Furthermore, in the terminal 16, as described above, the terminal head 32 protrudes outward relative to the terminal shaft 31. Therefore, in the terminal 16, a step is formed by the head end face 35 at the boundary between the terminal head 32 and the terminal shaft 31. In the terminal 16, due to the step at the boundary between the terminal shaft 31 and the terminal head 32, the outer circumferential surface of the terminal head 32 is located on the outer circumferential side relative to the outer circumferential surface of the terminal shaft 31. In the terminal head 32, the outer circumferential surface of the terminal head 32 extends continuously along the axial direction of the terminal 16 between the head end faces 33, 35, and extends around the entire circumferential direction of the terminal 16.

[0034] In the terminal head 32 of the terminal 16, the head end face (first head end face) 33 forms the end farther from the outer surface of the cover member 6 (the outer surface of the exterior part 3), and the head end face (second head end face) 35 forms the end closer to the outer surface of the cover member 6. In the terminal head 32, the head end face 33 faces the side opposite to the side on which the outer surface of the cover member 6 is located, and the head end face 35 faces the outer surface of the cover member 6. The terminal head 32 does not abut against the exterior part 3 (cover member 6), and is arranged with a gap between the head end face 35 and the outer surface of the cover member 6. Therefore, in the terminal 16, a separation distance D1 between the outer surface of the cover member 6 and the terminal head 32 is defined.

[0035] Furthermore, the head end surface 33 of the terminal head 32 of the terminal 16 forms the protruding end of the portion that protrudes from the outer surface of the cover member 6, and the head end surface 33 serves as the protruding end face of the portion that protrudes from the outer surface of the cover member 6. The protruding height H1 of the terminal 16 is defined as the dimension from the base of the protruding portion of the terminal head 32 to the protruding end. The protruding height H1 of the terminal 16 corresponds to the distance along the axial direction (the height direction of the battery 1) from the outer surface of the cover member 6 to the head end surface 33 that forms the protruding end face. The distance D2 of the terminal 16 corresponds to the distance along the axial direction between the head end surfaces 33, 35 of the terminal head 32.

[0036] 1 to 5, the terminal 16 defines a distance D3 along the width of the battery 1 from the outer peripheral surface of the terminal head 32 to one of the pair of short edges 17 of the cover member 6 that is closer. The terminal 16 also defines a distance D4 along the depth of the battery 1 from the outer peripheral surface of the terminal head 32 to each of the pair of long edges 18 of the cover member 6. Distance D4 is smaller than distance D3.

[0037] The gasket 27 covers the terminal shaft 31 of the terminal 16 from the outer periphery in the through hole 25 (one of the positive electrode side through hole and the negative electrode side through hole). The gasket 27 covers the terminal shaft 31 from the outer periphery around the entire circumferential circumference of the terminal 16. The gasket 27 is sandwiched between the terminal shaft 31 of the terminal 16 and the periphery of the through hole 25. That is, the positive electrode side gasket is sandwiched between the terminal shaft 31 of the positive electrode terminal 16A and the periphery of the positive electrode side through hole, and the negative electrode side gasket is sandwiched between the terminal shaft 31 of the negative electrode terminal 16B and the periphery of the negative electrode side through hole.

[0038] With the above-described configuration, gasket 27 prevents terminal 16 from coming into contact with the periphery of through hole 25. Gasket 27 also maintains airtight and liquid-tightness between the periphery of through hole 25 and terminal shaft 31 of terminal 16. Therefore, at the attachment portion of terminal 16 to exterior part 3, gasket 27 prevents electrolyte, gas, and the like from leaking from internal cavity 10 to the outside of exterior part 3 through through hole 25.

[0039] As shown in FIG. 5 and other figures, the insulator 26 has a bottom portion 41 that serves as the bottom wall and a covering portion 42 that serves as the peripheral wall. At the portion where the terminal 16 is attached to the cover member 6, the insulator 26 is disposed on the outer surface of the cover member 6 (the outer surface of the exterior part 3). The bottom portion 41 and covering portion 42 of the insulator 26 abut against the outer surface of the cover member 6. At the portion where the terminal 16 is attached, the bottom portion 41 of the insulator 26 is adjacent to the gasket 27 from the outer periphery and covers the entire circumference of the gasket 27 from the outer periphery. The bottom portion 41 of the insulator 26 is disposed in the gap between the terminal head 32 (head end surface 35) of the terminal 16 and the outer surface of the cover member 6, and is sandwiched between the terminal head 32 of the terminal 16 and the outer surface of the cover member 6. The terminal 16 is inserted into the internal cavity 10 by passing through the bottom portion 41 of the insulator 26.

[0040] In the insulator 26, the outer peripheral end of the bottom portion 41 is connected to the covering portion 42, and the entire circumference of the bottom portion 41 protrudes inward from the covering portion 42. Therefore, in the attachment portion of the terminal 16 to the cover member 6, the covering portion 42, the bottom portion 41, the gasket 27, and the terminal shaft 31 are arranged in this order from the outer peripheral side. In the insulator 26, the covering portion 42 extends from the connection position with the bottom portion 41 along the axial direction (center axis C) of the terminal 16. The insulator 26 is arranged in a state in which the covering portion 42 protrudes from the outer surface of the cover member 6.

[0041] The covering portion 42 of the insulator 26 covers the terminal head 32 of the terminal 16 from the outer periphery on the outer surface of the lid member 6. That is, the positive electrode side insulator 26A covers the terminal head 32 of the positive electrode terminal 16A from the outer periphery, and the negative electrode side insulator 26B covers the terminal head 32 of the negative electrode terminal 16B from the outer periphery. The insulator 26 covers the terminal head 32 of the terminal 16 from the outer periphery over the entire circumferential direction. Therefore, at the attachment portion of the terminal 16 to the lid member 6, the covering portion 42 and the terminal head 32 are arranged in this order from the outer periphery. At the attachment portion of the terminal 16, the inner periphery of the covering portion 42 of the insulator 26 abuts against the outer periphery of the terminal head 32.

[0042] The covering portion 42 of the insulator 26 has an extended end surface 43. The extended end surface 43 forms the end of the covering portion 42 opposite to the side connected to the bottom portion 41. The covering portion 42 of the insulator 26 extends along the axial direction of the terminal 16 from the connection position to the bottom portion 41 to the extended end surface 43. The extended end surface 43 forms the end of the covering portion 42 of the insulator 26 that is farther from the outer surface of the cover member 6 (the outer surface of the exterior portion 3). The extended end surface 43 of the covering portion 42 faces the side opposite to the side where the outer surface of the cover member 6 is located.

[0043] Furthermore, the extended end surface 43 of the covering portion 42 of the insulator 26 forms the protruding end of the portion protruding from the outer surface of the lid member 6, and the extended end surface 43 serves as the protruding end face of the portion protruding from the outer surface of the lid member 6. The protruding height H2 of the insulator 26 is defined as the dimension from the base of the protruding portion of the covering portion 42 to the protruding end. The protruding height H2 of the insulator 26 corresponds to the distance along the axial direction of the terminal 16 (the height direction of the battery 1) from the outer surface of the lid member 6 to the extended end surface 43, which serves as the protruding end face. The protruding height H2 of the covering portion 42 of the insulator 26 is greater than the distance D2 between the head end faces 33 and 35 of the terminal head 32 of the terminal 16. In other words, the distance between the extended end surface 43 of the covering portion 42 of the insulator 26 and the outer surface of the lid member 6, which corresponds to the protruding height H2, is greater than the distance D2 between the head end faces 33 and 35.

[0044] In this embodiment, at the attachment portion of the terminal 16 to the exterior part 3, the protruding height H2 of the covering portion 42 of the insulator 26 from the outer surface of the cover member 6 (exterior part 3) is equal to or greater than the protruding height H1 of the terminal head 32 of the terminal 16 from the outer surface of the cover member 6 over the entire circumferential direction of the terminal 16 (covering portion 42). In one example shown in FIGS. 1 to 5 , etc., the protruding height H2 of the covering portion 42 is greater than the protruding height H1 of the terminal head 32 over the entire circumferential direction. Therefore, in one example shown in FIGS. 1 to 5 , etc., the covering portion 42 further protrudes from the head end surface 33, which is the protruding end surface of the terminal head 32, toward the side opposite the side on which the outer surface of the cover member 6 is located, over the entire circumferential direction.

[0045] 1 to 5, in a configuration in which the protruding height H2 of the covering portion 42 is higher than the protruding height H1 of the terminal head 32 over the entire circumferential direction, a recess 46 is formed by the terminal head 32 of the terminal 16 and the covering portion 42 of the insulator 26. The recess 46 is recessed from the outer surface of the cover member 6 toward the side opposite to the side where the terminal head 32 and the covering portion 42 protrude. The recess 46 defines a bottom surface that serves as the bottom and an outer peripheral surface that covers the recess 46 from the outer peripheral side. The bottom surface of the recess 46 is formed by the terminal head 32 of the terminal 16 and is formed by the head end surface (first head end surface) 33 that serves as the protruding end surface of the terminal head 32. The outer peripheral surface of the recess 46 is formed by the inner peripheral surface of the covering portion 42 and is formed by a portion of the covering portion 42 that further protrudes from the head end surface 33 of the terminal head 32.

[0046] Furthermore, the covering portion 42 of the insulator 26 has a wall thickness T1 defined as the dimension from the inner peripheral surface to the outer peripheral surface in the radial direction. In one example of this embodiment, the wall thickness T1 of the covering portion 42 of the insulator 26 is equal to or greater than the separation distance D1 between the outer surface of the cover member 6 and the terminal head 32. The wall thickness T1 of the covering portion 42 is equal to or greater than the separation distance D1 over the entire circumferential direction. Therefore, the covering portion 42 is formed with a wall thickness T1 that is equal to or greater than the gap between the terminal head 32 and the outer surface of the cover member 6.

[0047] However, in this embodiment, when projected from the height direction of the battery 1, the outer peripheral surface of the covering portion 42 is located in an area surrounded by the peripheral edge 14 of the cover member 6 over the entire circumferential direction. The entire insulator 26, including the covering portion 42, is located between a pair of short edges 17 in the lateral direction of the battery 1 and between a pair of long edges 18 in the depth direction of the battery 1. Therefore, the covering portion 42 does not protrude outward beyond the peripheral edge 14 of the cover member 6, and does not protrude outward beyond each of the long edges 18 in the depth direction of the battery 1.

[0048] As shown in Figure 3 and other figures, the covering portion 42 of the insulator 26 that covers the outer periphery of the terminal head 32 of the terminal 16 comprises two pairs of adjacent portions 51, 52. The pair of adjacent portions (first adjacent portions) 51 are adjacent to the terminal head 32 on opposite sides in the horizontal direction of the battery 1. Therefore, the terminal head 32 is sandwiched between the pair of adjacent portions 51 in the horizontal direction of the battery 1. The pair of adjacent portions (second adjacent portions) 52 are adjacent to the terminal head 32 on opposite sides in the depth direction of the battery 1. Therefore, the terminal head 32 is sandwiched between the pair of adjacent portions 52 in the depth direction of the battery 1.

[0049] In this embodiment, the dimension of the lid member 6 in the depth direction of the battery 1 is smaller than the dimension of the lid member 6 in the lateral direction of the battery 1, and the distance D4 is smaller than the distance D3. For this reason, in this embodiment, it is preferable that the thickness T1b of each of the adjacent portions (second adjacent portions) 52 be smaller than the thickness T1a of each of the adjacent portions (first adjacent portions) 51.

[0050] 5 and other figures, in this embodiment, a pair of recesses 55 are formed on the outer surface of the cover member 6, with one recess 55 formed at each attachment portion of the terminals 16 to the cover member 6. When projected from the height direction of the battery 1, each of the recesses 55 is located within an area surrounded by the periphery 14 of the cover member 6. Below, one of the pair of recesses 55 and the configuration associated with that recess 55 will be described. Note that the other of the pair of recesses 55 and the configuration associated with that recess 55 will also be similar to the configuration described below.

[0051] In the attachment portion of the terminal 16, the recess 55 is recessed toward the side opposite to the side where the terminal head 32 and the covering portion 42 protrude from the outer surface of the cover member 6. The recess 55 defines a recessed bottom surface 56 that serves as the bottom, and a recessed outer peripheral surface 57 that covers the recess 55 from the outer peripheral side. In the attachment portion of the terminal 16, a through hole 25 is formed in the recessed bottom surface 56 of the recess 55. Furthermore, in the terminal 16, the entire terminal head 32 is located on the inner peripheral side of the recess 55 relative to the recessed outer peripheral surface 57. Therefore, the outer peripheral surface of the terminal head 32 is located on the inner peripheral side of the recess 55 (terminal 16) relative to the recessed outer peripheral surface 57. Furthermore, the terminal head 13 of the terminal 16 sandwiches the bottom portion 41 of the insulator 26 between the head end surface 35 and the recessed bottom surface 56.

[0052] The covering portion 42 of the insulator 26 extends from a position on the inner periphery of the concave outer periphery 57 toward the outer periphery of the recess 55. The covering portion 42 extends beyond the concave outer periphery 57 to a position on the outer periphery of the concave outer periphery 57. Therefore, the covering portion 42 has an inner periphery portion 61 that is on the inner periphery of the concave outer periphery 57, and an outer periphery portion 62 that is on the outer periphery of the concave outer periphery 57. The covering portion 42 has the inner periphery portion 61 and the outer periphery portion 62 formed over the entire circumferential direction. The inner periphery portion 61 abuts against the concave bottom surface 56, and the outer periphery portion 62 abuts against the outer surface of the cover member 6 (the outer surface of the exterior part 3) in a region on the outer periphery of the concave outer periphery 57.

[0053] In the covering portion 42, a dimension T2, which is the area occupied by the inner circumferential portion 61 in the thickness T1 of the covering portion 42, is defined as the dimension of the inner circumferential portion 61 in the radial direction of the terminal 16. In the covering portion 42, a dimension T3, which is the area occupied by the outer circumferential portion 62 in the thickness T1 of the covering portion 42, is defined as the dimension of the outer circumferential portion 62 in the radial direction of the terminal 16. In the covering portion 42, the dimension T3 is equal to or greater than the dimension T2 over the entire circumferential direction. Note that the dimension T3 corresponds to the protruding length of the portion of the covering portion 42 that protrudes from the recess 55 toward the outer periphery.

[0054] Additionally, a distance D5 along the depth direction of the battery 1 is defined from the concave outer peripheral surface 57 to each of the long edges 18 of the lid member 6. In this embodiment, as described above, the entire insulator 26, including the covering portion 42, is positioned between the pair of long edges 18 in the depth direction of the battery 1. Therefore, the dimension T3 that the outer peripheral portion 62 occupies within the thickness T1 of the covering portion 42 is smaller than the distance D5.

[0055] In this embodiment, a battery module is assembled using a plurality of batteries 1 as described above. FIG. 6 shows an example of a battery module 70 of this embodiment. As shown in FIG. 6, the battery module 70 includes a plurality of the batteries 1 described above, and the plurality of batteries 1 are arranged in an array. The battery module 70 has defined a depth direction (the direction indicated by arrows X3 and X4), a lateral direction (the direction indicated by arrows Y3 and Y4) that intersects (is perpendicular or substantially perpendicular to) the depth direction, and a height direction (the direction indicated by arrows Z3 and Z4) that intersects (is perpendicular or substantially perpendicular to) both the depth direction and the lateral direction. In the battery module 70, the plurality of batteries 1 are arranged along the depth direction, and the depth direction coincides with or substantially coincides with the arrangement direction of the batteries 1.

[0056] Each of the multiple batteries 1 is arranged such that its depth direction coincides or nearly coincides with the depth direction of the battery module 70 and its width direction coincides or nearly coincides with the width direction of the battery module 70. The height direction of each of the multiple batteries 1 coincides or nearly coincides with the height direction of the battery module 70. In the battery module 70, the outer surfaces of the lid member 6 of the multiple batteries 1 face the same side relative to each other in the height direction. In the battery module 70, the terminal heads 32 of the terminals 16 of the multiple batteries 1 protrude from the outer surface of the lid member 6 on the same side relative to each other in the height direction.

[0057] In the battery module 70, the multiple batteries 1 are electrically connected to one another by bus bars 71 made of a conductive material. Therefore, one of the multiple batteries 1 is electrically connected to another battery 1, which is an additional battery, via the bus bar 71. In the example shown in FIG. 6, batteries 1 adjacent to one another in the arrangement direction are electrically connected in series by one bus bar 71. The multiple batteries 1 provided in the battery module 70 are electrically connected in series using the multiple bus bars 71. Note that the battery module 70 may also use one or more bus bars 71 to electrically connect the multiple batteries 1 in parallel. Furthermore, both a structure in which the multiple batteries 1 are electrically connected in series and a structure in which the multiple batteries 1 are electrically connected in parallel using one or more bus bars may be formed.

[0058] The busbar 71 is formed in a plate shape, and the busbar 71 has a defined thickness direction. In the battery module 70, the busbar 71 electrically connects two batteries 1 with the thickness direction of the busbar 71 coinciding or nearly coinciding with the height direction of the battery module 70. The busbar 71 also has an insertion piece 72 formed thereon. The insertion piece 72 protrudes to one side in the thickness direction of the busbar 71. In each of the multiple batteries 1 in the battery module 70, the protruding height H2 of the covering portion 42 of the insulator 26 at the attachment portion of each pair of terminals 16 is configured to be higher than the protruding height H1 of the terminal head 32 of the terminal 16 over the entire circumferential direction. Therefore, in each of the multiple batteries 1, the aforementioned recess 46 is formed at the attachment portion of each pair of terminals 16.

[0059] FIG. 7 illustrates a configuration for connecting bus bars 71 to terminals 16 of batteries 1 in a battery module 70. FIG. 7 illustrates a cross section perpendicular or nearly perpendicular to the lateral direction of the battery module 70. FIG. 7 also illustrates a cross section passing through one of a pair of terminals 16 in each of multiple batteries 1 and passing through one of the bus bars 71. Below, a configuration for connecting a bus bar 71 to any one of a pair of terminals 16 in one of the multiple batteries 1 will be described. Note that in the battery module 70, bus bars 71 are also connected to the other terminals 16 in the same manner as the configuration described below.

[0060] In this embodiment, the insertion piece portion 72 of the busbar 71 is inserted into the recess 46 formed by the terminal head 32 and the covering portion 42. The insertion piece portion 72 is then joined to the terminal head 32 while inserted in the recess 46. That is, the insertion piece portion 72 is joined to the head end surface (first head end surface) 33 of the terminal head 32, which forms the bottom surface of the recess 46, in the recess 46. By joining the insertion piece portion 72 to the terminal head 32 in the recess 46, the busbar 71 is connected to the terminal 16.

[0061] Furthermore, in the recess 46, the insertion piece portion 72 of the busbar 71 abuts against the outer peripheral surface of the recess 46, i.e., the inner peripheral surface of the covering portion 42. In this embodiment, when projected in the height direction of the battery 1, the recess 46 has a quadrangular or approximately quadrangular shape. When projected in the plate thickness direction of the busbar 71, the insertion piece portion 72 has a quadrangular or approximately quadrangular shape that is similar in shape to the quadrangular or approximately quadrangular shape of the recess 46 and has a slightly smaller area than the quadrangular or approximately quadrangular shape of the recess 46. Furthermore, in the recess 46, the insertion piece portion 72 abuts against the inner peripheral surface of the covering portion 42 (terminal 16) over the entire or approximately the entire circumferential circumference of the covering portion 42.

[0062] When assembling a battery module 70 or the like in which multiple batteries 1 are electrically connected, bus bars 71 are connected to the terminals 16, and the multiple batteries are electrically connected via the bus bars 71. Furthermore, to confirm the dimensions of the assembled battery module 70, measurements of the batteries 1 that form the battery module 70 are performed. In the battery 1 of this embodiment, the outer periphery of the terminal head 32 is covered by the covering portion 42 of the insulator 26 at the attachment portion of each terminal 16. The covering portion 42 abuts against the outer surface of the exterior portion 3 (the outer surface of the lid member 6), and the protruding height H2 of the covering portion 42 from the outer surface of the exterior portion 3 is equal to or greater than the protruding height H1 of the terminal head 32 from the outer surface of the exterior portion 3 along the entire periphery.

[0063] With this configuration, the covering 42 appropriately prevents the terminal head 32 from unintentionally contacting conductors such as metal parts and jigs during work such as assembling the battery module 70. This appropriately prevents short circuits caused by the terminal head 32 contacting conductors during work such as assembling a battery module using batteries 1 in which the terminal heads 32 of the terminals 16 are arranged outside the exterior casing 3.

[0064] Furthermore, at the attachment portion of each terminal 16, the protruding height H2 of the covering portion 42 is equal to or greater than the protruding height H1 of the terminal head 32, which increases the spatial distance and creepage distance between the bus bar 71 and the outer surface of the exterior portion 3 of each battery 1 (the outer surface of the lid member 6) in the battery module 70. This further effectively prevents short circuits from occurring between the bus bar 71 and the exterior portion 3.

[0065] Furthermore, in this embodiment, by making the protruding height H2 of the covering portion 42 greater than the protruding height H1 of the terminal head 32 over the entire circumference, a recess 46 is formed in the head end face (first head end face) 33 of the terminal head 32, recessed relative to the extended end face 43 of the covering portion 42. The formation of the recess 46 further appropriately prevents unintended contact of the terminal head 32 with a conductor. Furthermore, by forming the recess 46 at the attachment portion of each terminal 16, the creepage distance between the terminal head 32 and the outer peripheral region of the covering portion 42 on the outer surface of the exterior portion 3 is increased. This further appropriately prevents short circuits from occurring between each terminal 16 and the exterior portion 3 in the battery 1.

[0066] As described above, in this embodiment, the insulation between conductors is improved in the battery 1 and in the battery module 70 assembled from a plurality of batteries 1. This appropriately prevents short circuits from occurring during use of the battery 1, improving safety. Furthermore, the occurrence of short circuits is appropriately prevented during the assembly of the battery module 70 and during use of the battery module 70, improving safety.

[0067] In addition, in this embodiment, the distance between the extended end surface 43 of the covering portion 42 of the insulator 26 and the outer surface of the exterior portion 3 is greater than the distance D2 between the head end surfaces 33, 35 of the terminal head 32. Therefore, it is possible to easily realize a configuration in which the protruding height H2 of the covering portion 42 of the insulator 26 is equal to or greater than the protruding height H1 of the terminal head 32 of the terminal 16 at each mounting portion of the terminal 16.

[0068] 1 to 5, the thickness T1 of the covering portion 42 of the insulator 26 is equal to or greater than the distance D1 between the outer surface of the exterior case 3 and the terminal head 32. In the example shown in FIGS. 1 to 5, a recess 55 is formed in the outer surface of the exterior case 3 at the attachment portion of each terminal 16, and the terminal head 32 is located on the inner side of the recessed outer surface 57 of the recess 55. The covering portion 42 of the insulator 26 extends from the inner side of the recessed outer surface 57 to the outer side of the recess 55, beyond the recessed outer surface 57. This configuration increases the thickness T1 of the covering portion 42. Furthermore, when the recess 55 is formed, the thickness T1 of the covering portion 42 can be further increased by setting the dimension T3 of the outer peripheral portion 62 on the outer side of the recessed outer surface 57 to be equal to or greater than the dimension T2 of the inner peripheral portion 61 on the inner side of the recessed outer surface 57.

[0069] In each of the batteries 1 forming the battery module 70, the thickness T1 of the covering portion 42 is increased at the attachment portion of each terminal 16, so that the covering portion 42 appropriately suppresses movement of the bus bar 71 connected to the terminal 16. For example, even if a force acts from the bus bar 71 on the covering portion 42 due to vibration or the like of the battery module 70, a reaction force against the force from the bus bar 71 acts appropriately from the covering portion 42 on the bus bar 71, and movement of the bus bar 71 is appropriately prevented by the reaction force from the covering portion 42. In other words, the fixing force of the bus bar 71 connected to the terminal 16 is improved. This effectively prevents the bus bar 71 from being separated from the terminal 16 due to vibration or the like of the battery module 70, improving the structural reliability of the battery module 70.

[0070] 6 and 7 , the insertion pieces 72 of the busbars 71 are inserted into the recesses 46 formed by the terminal heads 32 and the covering portions 42 at the connection portions of the busbars 71 to the terminals 16. The insertion pieces 72 of the busbars 71 are joined to the terminal heads 32 in the recesses 46. This configuration makes it easier to position the busbars 71 when assembling the battery module 70.

[0071] Furthermore, in the battery module 70, the insertion piece portion 72 of the bus bar 71 abuts against the outer circumferential surface of the recess 46, i.e., the covering portion 42, in the recess 46. This makes it even easier to position the bus bar 71 when assembling the battery module 70. Since it is easier to position the bus bar 71 when assembling the battery module 70, the workability of assembling the battery module 70 improves. This improves the productivity of the battery module 70.

[0072] 1 to 5, at each attachment portion of the terminals 16, the covering portion 42 includes a pair of adjacent portions 51 adjacent to the terminal head 32 on opposite sides in the lateral direction, and a pair of adjacent portions 52 adjacent to the terminal head 32 on opposite sides in the depth direction. In one example, the thickness T1b of each of the adjacent portions 52 is smaller than the thickness T1a of each of the adjacent portions 51. In manufacturing the battery 1, as described above, the lid member 6 is welded to the outer container 5. By reducing the thickness T1b, for example by making the thickness T1b smaller than the thickness T1a, the effect on the covering portion 42 of the heat generated by welding the lid member 6 to the outer container 5 is reduced.

[0073] (Variation) At the connection portions of the busbar 71 to the terminals 16, the insertion pieces 72 of the busbar 71 may abut against the inner circumferential surface of the covering portion 42 (terminals 16) (the outer circumferential surface of the recess 46) only over a partial range in the circumferential direction of the covering portion 42. In a battery module 70 of a first modification shown in FIG. 8 , when projected in the thickness direction of the busbar 71, the insertion pieces 72 have an elliptical or approximately elliptical shape that is smaller in area than the rectangular or approximately rectangular shape of the recess 46. In the battery module 70, the busbar 71 electrically connects two batteries 1 with the major axis direction of the elliptical or approximately elliptical shape of the insertion pieces 72 coinciding or approximately coinciding with the depth direction of the battery module 70 (the depth direction of each battery 1).

[0074] In this modification, too, at the connection portion of the busbar 71 to each of the terminals 16, the insertion piece portions 72 of the busbar 71 are inserted into the recesses 46, and the insertion piece portions 72 are joined to the head end surfaces 33 of the terminal heads 32 in the recesses 46. In this modification, the insertion piece portions 72 abut against the inner circumferential surface of the covering portion 42 (the outer circumferential surface of the recesses 46) only at two locations that are spaced apart from each other in the circumferential direction of the terminals 16 (covering portion 42). The inner circumferential surface of the covering portion 42 has portions where the insertion piece portions 72 abut, one for each of the pair of adjacent portions (second adjacent portions) 52, and the insertion piece portions 72 do not abut against the pair of adjacent portions (first adjacent portions) 51. In the recesses 46, the two locations where the insertion piece portions 72 abut against the covering portion 42 are located, for example, 180° or approximately 180° apart in the circumferential direction of the terminals 16.

[0075] In another variation, the busbar 71 electrically connects the two batteries 1 with the major axis direction of the elliptical or approximately elliptical shape of the insertion piece 72 coinciding or approximately coinciding with the lateral direction of the battery module 70 (the lateral direction of each of the batteries 1). In this case, too, the insertion piece 72 abuts against the inner circumferential surface of the covering portion 42 (the outer circumferential surface of the recess 46) only at two locations that are spaced apart from each other in the circumferential direction of the terminal 16 (covering portion 42). However, in this variation, the inner circumferential surface of the covering portion 42 has a portion where the insertion piece 72 abuts, one on each of a pair of adjacent portions (first adjacent portions) 51, and the insertion piece 72 does not abut against a pair of adjacent portions (second adjacent portions) 52.

[0076] In a battery module 70 according to a second modification shown in FIG. 9 , when projected in the thickness direction of the busbar 71, the insertion piece 72 has a circular or approximately circular shape that is smaller in area than the rectangular or approximately rectangular shape of the recess 46. In this modification, the insertion piece 72 abuts against the inner circumferential surface of the covering portion 42 (the outer circumferential surface of the recess 46) of the terminal 16 (covering portion 42) only at four locations that are spaced apart from one another in the circumferential direction of the terminal 16. The inner circumferential surface of the covering portion 42 has a portion where the insertion piece 72 abuts, one on each of the pair of adjacent portions (first adjacent portions) 51 and the pair of adjacent portions (second adjacent portions) 52. In the recess 46, the four locations where the insertion piece 72 abuts against the covering portion 42 are located at intervals of, for example, 90° or approximately 90° in the circumferential direction of the terminal 16.

[0077] 8 and 9, similarly to the first embodiment, the insertion piece portion 72 of the busbar 71 is joined to the terminal head 32 in the recess 46. Furthermore, the insertion piece portion 72 of the busbar 71 abuts against the outer circumferential surface of the recess 46, i.e., the covering portion 42. Therefore, even in the above-described modifications, the positioning of the busbar 71 is facilitated during the assembly of the battery module 70. Therefore, even in the above-described modifications, the workability of assembling the battery module 70 is improved, and the productivity of the battery module 70 is improved.

[0078] In addition, in the above-described embodiments, the exterior part 3 is configured to include the exterior container 5 and the lid member 6, but the configuration of the exterior part is not limited to this. As long as a pair of terminals 16 is attached to the exterior part, a configuration similar to any of the above-described embodiments can be applied to the attachment portions of the terminals 16 to the exterior part.

[0079] That is, in the above-described embodiment and modified examples, when the terminals 16 are attached to the respective exterior parts, the terminal heads 32 of the terminals 16 are positioned outside the exterior parts. The bottoms 41 of the insulators 26 are sandwiched between the terminal heads 32 and the outer surface of the exterior parts, and the coverings 42 of the insulators 26 cover the terminal heads 32 from the outer surface of the exterior parts around the terminals 16. The coverings 42 abut against the outer surface of the exterior parts, and the protruding height H2 of the coverings 42 from the outer surface of the exterior parts is equal to or greater than the protruding height H1 of the terminal heads 32 from the outer surface of the exterior parts over the entire circumference. This configuration appropriately prevents the terminal heads 32 from unintentionally contacting conductors during the assembly of a battery module, etc. This improves the insulation between conductors in the battery 1 and in battery modules assembled from multiple batteries 1, thereby improving safety.

[0080] Furthermore, in the battery 1, at least one of the attachment portion of the positive terminal 16A to the exterior and the attachment portion of the negative terminal 16B to the exterior may have the same configuration as in any of the above-described embodiments, etc. If the attachment portion of the positive terminal 16A to the exterior has the same configuration as in any of the above-described embodiments, etc., the positive terminal 16A will have the same configuration as any of the above-described terminals 16, and the positive electrode-side insulator 26A will have the same configuration as any of the above-described insulators 26. If the attachment position of the negative electrode terminal 16B to the exterior has the same configuration as in any of the above-described embodiments, etc., the negative electrode terminal 16B will have the same configuration as any of the above-described terminals 16, and the negative electrode-side insulator 26B will have the same configuration as any of the above-described insulators 26.

[0081] According to at least one of these embodiments or examples, the bottom of the insulator is sandwiched between the terminal head and the outer surface of the exterior housing, and the covering portion of the insulator covers the terminal head from the outer periphery of the terminal on the outer surface of the exterior housing. The covering portion abuts against the outer surface of the exterior housing, and the covering portion protrudes from the outer surface of the exterior housing to a height equal to or greater than the height of the terminal head protruding from the outer surface of the exterior housing along the entire periphery. This makes it possible to provide a battery and a battery module including such a battery that appropriately prevent unintended contact of the terminal head, which is located outside the exterior housing, with a conductor during work such as assembling the battery module.

[0082] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims.

Claims

1. an exterior portion having an internal cavity; an electrode group including a positive electrode and a negative electrode and housed in the internal cavity; a terminal that is inserted into the internal cavity through the exterior portion and electrically connected to the electrode group, the terminal having a terminal head that is disposed outside the exterior portion; an insulator having electrical insulation properties, comprising a bottom portion sandwiched between the terminal head and the outer surface of the exterior part, and a covering portion that covers the terminal head from the outer periphery of the terminal on the outer surface of the exterior part, wherein the covering portion abuts against the outer surface of the exterior part, and the height of the covering portion protruding from the outer surface of the exterior part is equal to or greater than the height of the terminal head protruding from the outer surface of the exterior part over the entire circumference; A battery comprising:

2. The battery of claim 1 , wherein the thickness of the covering portion is equal to or greater than the distance between the outer surface of the exterior portion and the terminal head.

3. The terminal head of the terminal is a first head end surface that forms an end of the terminal head that is farther from the outer surface of the exterior portion and faces away from the side where the outer surface of the exterior portion is located; a second head end surface that forms an end of the terminal head that is closer to the outer surface of the exterior portion and faces the outer surface of the exterior portion with the bottom portion of the insulator therebetween; Equipped with the covering portion of the insulator has an extended end surface that forms an end of the covering portion farther from the outer surface of the exterior portion and faces away from the side on which the outer surface of the exterior portion is located, a distance between the outer surface of the exterior portion and the extended end surface of the covering portion is greater than a distance between the first head end surface and the second head end surface of the terminal head; 10. The battery of claim 1.

4. The exterior part is an outer container having a bottom wall and a peripheral wall, the inner cavity of which opens to the side opposite to the side on which the bottom wall is located in the height direction; a cover member attached to the peripheral wall of the outer container in a state of closing the opening of the internal cavity, the cover member having the terminals passing therethrough; Equipped with the bottom portion of the insulator is sandwiched between the terminal head and the outer surface of the lid member; The covering portion of the insulator covers the terminal head from the outer peripheral side of the terminal on the outer surface of the cover member.

10. The battery of claim 1.

5. a dimension of the cover member in a depth direction intersecting with the height direction is smaller than a dimension of the cover member in a lateral direction intersecting with both the height direction and the depth direction; the covering portion of the insulator includes a pair of first adjacent portions adjacent to the terminal head of the terminal from opposite sides to each other in the lateral direction, and a pair of second adjacent portions adjacent to the terminal head of the terminal from opposite sides to each other in the depth direction, a thickness of each of the second adjacent portions is smaller than a thickness of each of the first adjacent portions; 5. The battery of claim 4.

6. the lid member has a periphery that forms an edge of the outer surface of the lid member; When projected from the height direction, the outer circumferential surface of the covering portion of the insulator is located in a range surrounded by the periphery of the cover member over the entire periphery.

5. The battery of claim 4.

7. the exterior portion includes a recess in the outer surface of the exterior portion, the recess defining a recessed bottom surface and a recessed outer circumferential surface; the terminal head of the terminal is located on the inner circumferential side of the recess with respect to the recessed outer circumferential surface, and sandwiches the bottom of the insulator between the terminal head and the recessed bottom surface; the covering portion of the insulator extends from a position on the inner circumferential side of the recess with respect to the recessed outer circumferential surface, beyond the recessed outer circumferential surface, to the outer circumferential side of the recess, 10. The battery of claim 1.

8. The battery of claim 7, wherein the thickness of the covering portion of the insulator is such that the dimension of the outer peripheral portion on the outer periphery side relative to the concave outer peripheral surface is equal to or greater than the dimension of the inner peripheral portion on the inner periphery side relative to the concave outer peripheral surface.

9. a positive electrode terminal electrically connected to the positive electrode of the electrode group is the terminal including the terminal head, and a positive electrode-side insulator corresponding to the positive electrode terminal is the insulator including the bottom portion and the covering portion; and a negative electrode terminal electrically connected to the negative electrode of the electrode group is the terminal including the terminal head, and a negative electrode-side insulator corresponding to the negative electrode terminal is the insulator including the bottom portion and the covering portion, 2. The battery of claim 1, wherein the battery is at least one of:

10. A battery according to any one of claims 1 to 9; a bus bar formed from a conductive material and connected to the terminal of the battery; an additional battery electrically connected to the battery via the bus bar; A battery module comprising:

11. In the battery, a recess is formed by the terminal head of the terminal and the covering portion of the insulator, In the recess, a bottom surface of the recess is formed by the terminal head, the bus bar includes an insertion piece portion to be inserted into the recess, The insertion piece portion of the bus bar is joined to the terminal head of the terminal in the recess. The battery module of claim 10.

12. In the recess, an outer circumferential surface of the recess is formed by the covering portion, the insertion piece portion of the bus bar abuts against the outer circumferential surface of the recess in the recess; The battery module of claim 11.

Images