阅读说明：本技术 电池、电池组以及车辆 (Battery, battery pack, and vehicle ) 是由 山本晋聪 于 2019-09-13 设计创作，主要内容包括：根据实施方式,电池具备：外装容器、电极组、盖部件、集电片、电极端子、引线、绝缘防护装置、以及一对突起。外装容器具备底壁及周壁,周壁具备在纵向上隔着内部空洞彼此相对地对置的一对侧壁。集电片在内部空洞中从电极组向横向突出,绝缘防护装置在内部空洞中使引线和集电片相对于外装容器的内表面电绝缘。一对突起分别从绝缘防护装置突出,并抵接于一对侧壁的对应一方与底壁的边界部分。(According to an embodiment, a battery includes: an exterior container, an electrode group, a cover member, a current collecting tab, an electrode terminal, a lead, an insulating protector, and a pair of protrusions. The outer container includes a bottom wall and a peripheral wall, and the peripheral wall includes a pair of side walls facing each other with an internal cavity therebetween in a longitudinal direction. The current collecting tab protrudes laterally from the electrode group in the internal cavity, and the insulating protector electrically insulates the lead and the current collecting tab from the inner surface of the outer container in the internal cavity. The pair of projections respectively project from the insulating protector and abut on a boundary portion between a corresponding one of the pair of side walls and the bottom wall.)

1. A battery is provided with:

an outer container including a bottom wall and a peripheral wall, an internal cavity defined by the bottom wall and the peripheral wall opening to an opposite side of the bottom wall in a height direction, the peripheral wall including a first side wall and a second side wall facing each other with the internal cavity therebetween in a longitudinal direction intersecting the height direction;

an electrode group including a positive electrode and a negative electrode, and accommodated in the internal cavity of the outer container;

a lid member attached to the peripheral wall at an end portion opposite to the bottom wall, for closing an opening of the internal cavity;

a collector tab protruding from the electrode group in the internal cavity in a lateral direction intersecting both the longitudinal direction and the height direction;

an electrode terminal attached to an outer surface of the cover member;

a lead wire disposed in the internal cavity and electrically connecting the current collecting tab to the electrode terminal;

an insulation protector made of an electrically insulating material for electrically insulating the lead and the current collecting tab from the inner surface of the outer container in the internal cavity;

a first protrusion connected to the insulation shield and protruding from the insulation shield, the protruding end abutting a boundary portion of the first sidewall and the bottom wall; and

and a second protrusion connected to the insulation shield and protruding from the insulation shield, the protruding end abutting against a boundary portion of the second sidewall and the bottom wall.

2. The battery according to claim 1,

the first protrusion and the second protrusion protrude outward from the insulation protector in the longitudinal direction or protrude toward the bottom wall side from the insulation protector in the height direction, respectively.

3. The battery according to claim 1 or 2,

the first projection and the second projection are each formed in a plate shape whose width direction is along the lateral direction of the outer container.

4. The battery according to any one of claims 1 to 3,

the first protrusion and the second protrusion are each formed of an electrically insulating material.

5. The battery according to any one of claims 1 to 4,

the first protrusion and the second protrusion are respectively formed integrally with the insulation guard.

6. The battery according to any one of claims 1 to 5,

the dimension of the internal cavity of the outer container in the longitudinal direction is smaller than the dimension of the internal cavity in the transverse direction and the dimension of the internal cavity in the height direction, respectively.

7. The battery according to any one of claims 1 to 6,

the insulation shield device includes a shield device bottom surface facing the bottom wall,

the protection device bottom surface possesses:

a first inclined surface that forms an edge on a side where the first side wall is located on the guard bottom surface and is inclined in a state of being away from the bottom wall in the height direction as approaching the first side wall in the longitudinal direction; and

a second inclined surface which forms an edge on a side where the second side wall is located on the guard bottom surface and is inclined in a state of being apart from the bottom wall in the height direction as approaching the second side wall in the longitudinal direction,

the first protrusion protrudes from the first inclined face toward the boundary portion of the first side wall and the bottom wall,

the second protrusion protrudes from the second inclined face toward the boundary portion of the second side wall and the bottom wall.

8. The battery according to any one of claims 1 to 7,

the peripheral wall of the outer container includes a third side wall continuously extending in the longitudinal direction between the first side wall and the second side wall and adjacent to the internal cavity from the one lateral side,

the insulation protection device is provided with:

a first protector side plate portion interposed between the lead wire and an inner surface of the first side wall;

a second protector side plate portion interposed between the lead wire and an inner surface of the second side wall;

a third protector side plate portion interposed between the lead wire and an inner surface of the third side wall; and

a protector bottom plate portion interposed between the lead wire and an inner surface of the bottom wall,

the guard bottom plate portion includes a guard protruding portion protruding toward the electrode group in the lateral direction with respect to the first guard side plate portion and the second guard side plate portion,

the guard projection is disposed between the electrode group and the bottom wall, and supports the electrode group from the side of the bottom wall in the height direction.

9. The battery according to claim 8,

the first protrusion protrudes from the guard protrusion toward the boundary portion of the first side wall and the bottom wall,

the second protrusion protrudes from the guard protrusion toward the boundary portion of the second side wall and the bottom wall.

10. The battery according to any one of claims 1 to 9,

the collector sheet is provided with: a positive electrode collector tab projecting from the electrode group to one side in the lateral direction, and a negative electrode collector tab projecting from the electrode group to the opposite side to the side on which the positive electrode collector tab projects in the lateral direction,

the electrode terminal is provided with a positive electrode terminal and a negative electrode terminal,

the lead wire is provided with: a positive electrode side lead for electrically connecting the positive electrode collector tab to the positive electrode terminal, and a negative electrode side lead for electrically connecting the negative electrode collector tab to the negative electrode terminal,

the insulation protection device is provided with: a positive electrode side insulation protector for electrically insulating the positive electrode side lead and the positive electrode current collecting tab from the inner surface of the outer container, and a negative electrode side insulation protector for electrically insulating the negative electrode side lead and the negative electrode current collecting tab from the inner surface of the outer container,

the first projection may project from only one of the positive electrode side protector and the negative electrode side protector, or may project from each of the positive electrode side protector and the negative electrode side protector by one or more projections,

the second protrusion may protrude from only one of the positive electrode side protector and the negative electrode side protector, or may protrude from each of the positive electrode side protector and the negative electrode side protector by one or more than one.

11. A battery pack comprising one or more batteries according to any one of claims 1 to 10.

12. A vehicle provided with the battery pack according to claim 11.

Technical Field

Embodiments of the invention relate to a battery, a battery pack, and a vehicle.

Background

With the progress of electronic devices such as mobile phones and personal computers, batteries such as secondary batteries used in these electronic devices are required to be reduced in size and weight. As a secondary battery having a high energy density and reduced size and weight, a lithium ion secondary battery is given. On the other hand, secondary batteries such as lead storage batteries and nickel metal hydride batteries are used as large-sized, large-capacity power sources mounted on vehicles such as electric vehicles, hybrid vehicles, electric motorcycles, and forklifts. In recent years, lithium ion secondary batteries having high energy density have been developed for use as large-sized and large-capacity power sources mounted on vehicles. In the development of lithium ion secondary batteries mounted on vehicles, it is required to increase the battery life and safety, and to increase the size and capacity of the batteries.

As a battery such as a lithium ion secondary battery, there is a battery in which an electrode group including a positive electrode and a negative electrode is accommodated in an internal cavity of an outer container. In this battery, the outer container includes a bottom wall and a peripheral wall, and the internal cavity of the outer container is open to the opposite side of the bottom wall in the height direction. A lid member is attached to the peripheral wall of the outer container, and the opening of the inner cavity is closed by the lid member. In the battery, electrode terminals are attached to the outer surface of the lid member, and the current collecting tabs protrude from the electrode group toward the outer peripheral side in the internal cavity. The current collecting tab is electrically connected to the electrode terminal via a lead. In addition, an insulating protector made of an electrically insulating material is disposed in the internal cavity, and the lead and the current collecting tab are prevented from contacting the inner surface of the outer container by the insulating protector. Thus, the lead and the current collecting piece are electrically insulated from the outer container.

In the battery as described above, the internal components such as the electrode group and the like accommodated in the internal cavity are restrained by the peripheral wall of the outer container and the like. Therefore, even if external impact such as vibration occurs during traveling of the vehicle on which the battery is mounted, the influence of the external impact on the internal components including the electrode group, the current collecting tab, the lead, and the insulation protector can be suppressed.

Here, if the battery as described above is used, gas is generated from the electrode group in the internal cavity. The outer container expands due to gas generated in the internal cavity. In the battery, it is required that the internal components can be appropriately restrained by the peripheral wall of the outer container and the like even when gas is generated in the internal cavity. In addition, it is required to ensure the insertability of the contents into the inner cavity of the outer container when manufacturing the battery.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2006-40901

Disclosure of Invention

Technical problem to be solved

An object of the present invention is to provide a battery, a battery pack including the battery, and a vehicle, in which even if an outer container swells, a built-in object can be appropriately restrained in an internal cavity, and insertion of the built-in object into the internal cavity can be ensured at the time of manufacturing.

(II) technical scheme

According to an embodiment, a battery includes: the electrode assembly includes an outer container, an electrode group, a lid member, a current collecting tab, an electrode terminal, a lead, an insulating protector, a first protrusion, and a second protrusion. The outer container includes a bottom wall and a peripheral wall, and an internal cavity defined by the bottom wall and the peripheral wall is open to the opposite side of the bottom wall in the height direction. The peripheral wall includes a first side wall and a second side wall facing each other with an internal cavity therebetween in a longitudinal direction intersecting with the height direction. The electrode group includes a positive electrode and a negative electrode, and is accommodated in the internal cavity of the outer container. The cover member is attached to the peripheral wall at an end opposite to the bottom wall, and closes an opening of the internal cavity. The collector tab protrudes from the electrode group in a transverse direction intersecting both the longitudinal direction and the height direction in the internal cavity. The electrode terminals are mounted to an outer surface of the cap member. The lead is disposed in the internal cavity and electrically connects the collector tab to the electrode terminal. The insulating protector is made of an electrically insulating material, and electrically insulates the lead and the current collecting tab from the inner surface of the outer container in the inner cavity. The first protrusion and the second protrusion are connected to the insulation protector, respectively, and protrude from the insulation protector. The protruding end of the first protrusion abuts against the boundary portion of the first side wall and the bottom wall, and the protruding end of the second protrusion abuts against the boundary portion of the second side wall and the bottom wall.

According to an embodiment, there is provided a battery pack including one or more of the above-described batteries.

According to an embodiment, a vehicle is provided with the battery pack.

Drawings

Fig. 1 is a perspective view schematically showing a battery according to a first embodiment in an exploded state of each member.

Fig. 2 is a perspective view schematically showing the assembled state of the battery according to the first embodiment.

Fig. 3 is a schematic diagram showing an example of the structure of the electrode group of the battery according to the first embodiment.

Fig. 4 is a schematic diagram showing the structure of the internal cavity of the battery of fig. 1.

Fig. 5 is a sectional view schematically showing a section along the line a1-a1 of fig. 4.

Fig. 6 is a perspective view schematically showing the structure of the insulation protector of the battery according to the first embodiment.

Fig. 7 is a perspective view schematically showing the insulation shield apparatus of fig. 6 in a state of being viewed from a direction different from that of fig. 6.

Fig. 8 is a schematic view of the insulating protector of fig. 6 as viewed from the side of the protector protruding portion.

Fig. 9 is a schematic view of the insulation shield device of fig. 6 as viewed from the outer surface of the shield side plate (one of the first shield side plate and the second shield side plate) toward the outside.

Fig. 10 is a cross-sectional view schematically showing a state in which each side wall (long side wall) of the battery of fig. 1 is expanded.

Fig. 11 is a cross-sectional view schematically showing a state in which the built-in object is inserted into the internal cavity when the battery of fig. 1 is manufactured.

Fig. 12 is a schematic diagram showing the structure of an internal cavity of the battery according to the first modification.

Fig. 13 is a cross-sectional view schematically showing the structure of an internal cavity of a battery according to a second modification.

Fig. 14 is a cross-sectional view schematically showing the structure of an internal cavity of a battery according to a third modification.

Fig. 15 is a schematic diagram showing an example of a battery pack using the battery according to the embodiment.

Fig. 16 is a schematic diagram showing an example in which the assembled battery according to the embodiment is applied to a vehicle.

Detailed Description

(Battery)

First, the battery of the embodiment will be explained.

(first embodiment)

First, the battery 1 of the first embodiment is shown as an example of the battery of the embodiment. Fig. 1 and 2 show an example of a battery 1 according to a first embodiment. Here, fig. 1 is an exploded view of the respective components of the battery 1, and fig. 2 shows an assembled state of the battery 1. The battery 1 is, for example, a secondary battery.

As shown in fig. 1 and 2, the battery 1 includes an exterior portion 3. The exterior portion 3 is formed of a metal such as aluminum, an aluminum alloy, iron, or stainless steel. Further, an inner cavity 11 is formed inside the exterior portion 3. The battery 1 and the exterior portion 3 define: a longitudinal direction (the direction indicated by arrow X1 and arrow X2), a lateral direction (the direction indicated by arrow Y1 and arrow Y2) intersecting (perpendicular or substantially perpendicular) the longitudinal direction, and a height direction (the direction indicated by arrow Z1 and arrow Z2) intersecting (perpendicular or substantially perpendicular) both the lateral direction and the longitudinal direction.

The exterior portion 3 includes an exterior container 5 and a lid member 6. In the present embodiment, the outer container 5 includes the bottom wall 7 and the peripheral wall 4, and the inner cavity 11 is defined by the bottom wall 7 and the peripheral wall 4. The bottom wall 7 is positioned on one side (arrow Z2 side) in the height direction with respect to the internal cavity 11. The peripheral wall 4 extends along the circumferential direction of the outer container 5, and the outer peripheral side of the internal cavity 11 is surrounded by the peripheral wall 4. The internal cavity 11 is open in the height direction to the side opposite to the side where the bottom wall 7 is located (arrow Z1 side). Therefore, in the example shown in fig. 1 and 2, the outer container 5 is formed in a substantially rectangular parallelepiped shape with one surface opened. Here, the direction along the opening edge of the internal cavity 11 coincides with or substantially coincides with the circumferential direction in the battery 1 and the exterior portion 3. The side of the peripheral wall 4 on which the internal cavity 11 (internal space) is located is the inner peripheral side, and the opposite side to the inner peripheral side is the outer peripheral side.

The peripheral wall 4 includes two pairs of side walls 8A, 8B, 9A, 9B. The pair of side walls 8A, 8B are opposed to each other across the internal cavity 11 in the longitudinal direction. The pair of side walls 9A and 9B face each other across the internal cavity 11 in the lateral direction. The side walls 8A, 8B extend continuously in the lateral direction between the side walls 9A, 9B, respectively. In addition, the side walls 9A, 9B extend continuously in the longitudinal direction between the side walls 8A, 8B, respectively. With the above-described configuration, the first side wall, which is one of the side walls 8A and 8B, is adjacent to the internal cavity 11 from one side in the longitudinal direction, and the second side wall, which is the other of the side walls 8A and 8B, is adjacent to the internal cavity 11 from the opposite side to the first side wall in the longitudinal direction. A third side wall, which is one of the side walls 9A, 9B, is adjacent to the internal cavity 11 from one side in the lateral direction, and a fourth side wall, which is the other of the side walls 9A, 9B, is adjacent to the internal cavity 11 from the opposite side of the third side wall in the lateral direction.

The lid member 6 is attached to the outer container 5 at the opening of the inner cavity 11. That is, the lid member 6 is attached to the peripheral wall 4 at the end opposite to the bottom wall 7. The lid member 6 closes the opening of the internal cavity 11. In the present embodiment, the lid member 6 is provided in a state in which the thickness direction of the lid member 6 coincides or substantially coincides with the height direction of the battery 1.

In the present embodiment, the dimension in the longitudinal direction between the pair of side walls 8A, 8B is much smaller than the dimension in the height direction between the bottom wall 7 and the cover member 6, and the dimension in the lateral direction between the pair of side walls 9A, 9B. Therefore, in the inner hollow, the dimension in the longitudinal direction is much smaller than the dimension in the lateral direction, as well as the dimension in the height direction. Therefore, in the external container 5, the side walls 8A, 8B are long side walls, respectively, and the side walls 9A, 9B are short side walls, respectively. The thickness of the exterior portion 3 (the exterior container 5 and the lid member 6) is formed uniformly or substantially uniformly over the entire exterior portion 3. Therefore, in the battery 1, the dimension in the longitudinal direction is much smaller than the dimension in the lateral direction, as well as the dimension in the height direction. The thickness of the exterior portion 3 is formed to be thin, for example, 0.02mm to 0.3 mm.

The electrode group 10 is accommodated in the inner cavity 11 of the exterior portion 3. Fig. 3 is a diagram illustrating the structure of the electrode group 10. As shown in fig. 3, the electrode group 10 is formed in a flat shape, for example, and includes a positive electrode 21, a negative electrode 22, and separators 23 and 25. The positive electrode 21 includes: positive electrode current collector foil 21A serving as a positive electrode current collector, and positive electrode active material-containing layer 21B supported on the surface of positive electrode current collector foil 21A. Positive electrode 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. Positive electrode current collector foil 21A is coated with a paste containing a positive electrode active material, a binder, and a conductive agent. The positive electrode active material is not limited to these, and examples thereof include oxides, sulfides, and polymers capable of absorbing and desorbing lithium. In addition, from the viewpoint of obtaining a high positive electrode potential, it is preferable to use a lithium manganese composite oxide, a lithium nickel composite oxide, a lithium cobalt composite oxide, lithium iron phosphate, or the like as the positive electrode active material.

The negative electrode 22 includes a negative electrode current collector foil 22A serving as a negative electrode current collector, and a negative electrode active material-containing layer 22B supported on the surface of the negative electrode current collector foil 22A. Negative electrode current 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 paste containing a negative electrode active material, a binder, and a conductive agent is applied to negative electrode current collector foil 22A. The negative electrode active material is not particularly limited, and examples thereof include a metal oxide, a metal sulfide, a metal nitride, a carbon material, and the like, which can absorb and release lithium ions. The negative electrode active material is preferably a material having a lithium ion absorption/release potential of 0.4V or more with respect to the metal lithium potential, that is, a material having a lithium ion absorption/release potential of 0.4V (vs⁺/Li) or more. By using a negative electrode active material having such a lithium ion absorption/release potential, an alloy reaction between lithium and aluminum or an aluminum alloy is suppressed, and therefore, the negative electrode active material can be used in a negative stateAluminum or an aluminum alloy is used for the electrode collector foil 22A and the structural members related to the negative electrode 22. The potential for absorption and release of lithium ions was 0.4V (vs. Li)⁺Li), for example, a lithium titanium composite oxide such as titanium oxide or lithium titanate, a tungsten oxide, an amorphous tin oxide, a niobium/titanium composite oxide, a tin silicon oxide, or the like, and particularly, a lithium titanium composite oxide is preferably used as the negative electrode active material. When a carbon material that absorbs and releases lithium ions is used as the negative electrode active material, a copper foil may be used as the negative electrode current collector foil 22A. With respect to the carbon material used as the negative electrode active material, the absorption/emission potential of lithium ions is 0V (vs⁺/Li) or so.

The aluminum alloy used for positive electrode current collector foil 21A and negative electrode current collector foil 22A preferably contains one or two or more elements selected from Mg, Ti, Zn, Mn, Fe, Cu, and Si. The purity of aluminum and aluminum alloys may be 98 wt% or more, preferably 99.99 wt% or more. Further, pure aluminum having a purity of 100% may be used as a material of 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).

Positive electrode current collector foil 21A has one long edge 21C and a portion near the one long edge 21C to form positive electrode current collector tab 21D. In the example of fig. 3, positive electrode collector tab 21D is formed over the entire length of long edge 21C. In positive current collector sheet 21D, positive electrode active material-containing layer 21B is not supported on the surface of positive current collector foil 21A. Therefore, positive electrode current collector foil 21A includes positive electrode current collector sheet 21D as a portion not carrying positive electrode active material containing layer 21B. In the negative electrode current collector foil 22A, a negative electrode current collector tab 22D is formed by one long edge 22C and its vicinity. In the example of fig. 3, the negative electrode collector tab 22D is formed over the entire length of the long edge 22C. In negative current collector sheet 22D, negative active material-containing layer 22B is not supported on the surface of negative current collector foil 22A. Therefore, the negative electrode current collector foil 22A includes the negative electrode current collector sheet 22D as a portion not carrying the negative electrode active material containing layer 22B.

The separators 23, 25 are each formed of an electrically insulating material, and electrically insulate the positive electrode 21 and the negative electrode 22 from each other. The separators 23, 25 may be sheets or the like that are not integral with the positive electrode 21 and the negative electrode 22, respectively, or may be integral with one of the positive electrode 21 and the negative electrode 22. The spacers 23 and 25 may be formed of an organic material, an inorganic material, or a mixture of an organic material and an inorganic material. Examples of the organic material forming the separators 23 and 25 include engineering plastics and super engineering plastics. Examples of the engineering plastic include polyamide, polyoxymethylene, polybutylene terephthalate, polyethylene terephthalate, syndiotactic/polystyrene, polycarbonate, polyamideimide, polyvinyl alcohol, polyvinylidene fluoride, and modified polyphenylene ether. Examples of the super engineering plastic include polyphenylene sulfide, polyether ether ketone, liquid crystal polymer, polyvinylidene fluoride, Polytetrafluoroethylene (PTFE), polyether nitrile, polysulfone, polyacrylate, polyether imide, and thermoplastic polyimide. Examples of the inorganic material forming the spacers 23 and 25 include oxides (e.g., alumina, silica, magnesia, phosphate, calcium oxide, iron oxide, and titanium oxide), nitrides (e.g., boron nitride, aluminum nitride, silicon nitride, and barium nitride), and the like.

In the electrode group 10, the positive electrode 21, the negative electrode 22, and the separators 23 and 25 are wound in a flat shape around the winding axis B with the separators 23 and 25 interposed between the positive electrode active material containing layer 21B and the negative electrode active material containing layer 22B, respectively. The positive electrode 21, the separator 23, the negative electrode 22, and the separator 25 are wound in a state of being stacked in this order, for example. In electrode group 10, positive current collecting tab 21D of positive current collector foil 21A protrudes to one side in the direction along winding axis B with respect to negative electrode 22 and separators 23 and 25. Negative current collecting tab 22D of negative current collecting foil 22A projects toward the opposite side of the projecting side of positive current collecting tab 21D with respect to positive electrode 21 and separators 23 and 25 in the direction along winding axis B.

The electrode group 10 is disposed in a state where 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 portion 3, the positive electrode current collecting tab 21D protrudes laterally to one side of the negative electrode 22 and the separators 23 and 25. The negative electrode current collecting tab 22D protrudes from the positive electrode 21 and the separators 23 and 25 toward the side opposite to the side from which the positive electrode current collecting tab 21D protrudes in the lateral direction. Therefore, the collector tabs 21D, 22D protrude from the electrode group 10 toward the outer peripheral side in the internal cavity 11. In the example of fig. 1 and 2, the positive electrode collector tab 21D protrudes from the electrode group 10 toward the side wall 9A. The negative electrode collector tab 22D protrudes from the electrode group 10 toward the side wall 9B.

In the electrode group 10, the exposed portion in the internal cavity 11 is formed of a material having electrical insulation properties, except for the current collecting tabs 21D and 22D. In the electrode group 10, the exposed portions other than the current collecting tabs 21D, 22D are formed by, for example, either the separators 23, 25 or an insulating sheet that is not integral with the separators 23, 25.

In addition, the electrode group 10 does not need to have a winding structure in which the positive electrode, the negative electrode, and the separator are wound. In one embodiment, the electrode assembly 10 has a stack structure in which a plurality of positive electrodes and a plurality of negative electrodes are alternately stacked, with a separator disposed between the positive electrodes and the negative electrodes. In this case, too, in the electrode group 10, the positive electrode current collecting tab protrudes toward the negative electrode side in the lateral direction of the battery 1 (exterior portion 3). In the electrode group, the negative electrode current collecting tab protrudes toward the side opposite to the side from which the positive electrode current collecting tab protrudes in the lateral direction of the battery 1. Therefore, the collector tabs protrude from the electrode group 10 toward the outer circumferential side in the internal cavity 11.

In one embodiment, the electrode assembly 10 is impregnated with an electrolyte (not shown) in the internal cavity 11. As the electrolytic solution, a nonaqueous electrolytic solution prepared by dissolving an electrolyte in an organic solvent, for example, is used. In this case, the electrolyte dissolved in the organic solvent may be lithium perchlorate (LiClO)₄) Lithium arsenic hexafluoride (LiPF)₆) Lithium tetrafluoroborate (LiBF)₄) Lithium arsenic hexafluoride (LiAsF)₆) Lithium trifluoromethanesulfonate (LiCF)₃SO₃) And lithium bistrifluoromethylsulfonyl imide (LiN (CF)₃SO₂)₂) And the like lithium salts, and mixtures thereof. Examples of the organic solvent include Propylene Carbonate (PC), Ethylene Carbonate (EC), and vinylene carbonateCyclic carbonates, chain carbonates such as diethyl carbonate (DEC), dimethyl carbonate (DMC) and ethyl methyl carbonate (MEC), cyclic ethers such as Tetrahydrofuran (THF), 2 methyltetrahydrofuran (2MeTHF) and Dioxolane (DOX), chain ethers such as Dimethoxyethane (DME) and Diethoxyethane (DEE), γ -butyrolactone (GBL), Acetonitrile (AN) and Sulfolane (SL), and the like. These organic solvents are used alone or as a mixed solvent.

In one embodiment, a gel-like nonaqueous electrolyte in which a nonaqueous electrolytic solution and a polymer material are combined is used instead of the electrolytic solution. In this case, the electrolyte and the organic solvent described above are used. Examples of the polymer material include polyvinylidene fluoride (PVdF), Polyacrylonitrile (PAN), and polyethylene oxide (PEO).

In one embodiment, a solid electrolyte such as a polymer solid electrolyte or an inorganic solid electrolyte is used as the nonaqueous electrolyte instead of the electrolytic solution. In this case, the separators 23, 25 may not be provided in the electrode group 10. In the electrode group 10, a solid electrolyte is interposed between the positive electrode 21 and the negative electrode 22 instead of the separators 23 and 25. Therefore, in the present embodiment, the cathode 21 and the anode 22 are electrically insulated from each other by the solid electrolyte. In addition, in one embodiment, an aqueous electrolyte containing an aqueous solvent may be used as the electrolyte instead of the nonaqueous electrolyte.

In the present embodiment, a pair of electrode terminals 27A and 27B are attached to the outer surface of the lid member 6, that is, the surface of the lid member 6 opposite to the bottom wall 7. In the example of fig. 1 and 2, the electrode terminal 27A is a positive electrode terminal of the battery 1, and the electrode terminal 27B is a negative electrode terminal of the battery 1. The electrode terminals 27A and 27B each include a head portion 31 and a shaft portion 32. The electrode terminals 27A and 27B are attached to the outer surface of the lid member 6 in a state where the head portion 31 is exposed to the outside of the exterior portion 3. In the present embodiment, the electrode terminals 27A, 27B are arranged to face each other in a laterally spaced manner. Also, the center position of the battery 1 in the lateral direction is located between the electrode terminals 27A, 27B. The electrode terminals 27A and 27B are each formed of a conductive material, for example, any one of aluminum, copper, and stainless steel.

The lid member 6 is formed with a pair of through holes 33A and 33B. The through holes 33A and 33B are arranged laterally apart from each other. Further, the center position of the battery 1 in the lateral direction is located between the through holes 33A, 33B. The through holes 33A and 33B are formed along the thickness direction of the lid member 6, that is, the height direction of the battery 1, and penetrate the lid member 6. The shaft portion 32 of the electrode terminal 27A is inserted into the through hole 33A, and the shaft portion 32 of the electrode terminal 27B is inserted into the through hole 33B.

A pair of insulating members (external insulating members) 28A and 28B made of an electrically insulating material are provided on the outer surface of the lid member 6. The insulating member 28A is interposed between the outer surface of the lid member 6 and the electrode terminal 27A, and the insulating member 28B is interposed between the outer surface of the lid member 6 and the electrode terminal 27B. Therefore, the insulating members 28A, 28B are disposed apart from each other in the lateral direction, and the center position of the battery 1 in the lateral direction is located between the insulating members 28A, 28B. In the through hole 33A of the lid member 6, an insulating gasket 35A is disposed between the shaft portion 32 of the electrode terminal 27A and the lid member 6. In the through hole 33B, the insulating gasket 35B is disposed between the shaft portion 32 of the electrode terminal 27B and the lid member 6. The insulating member 28A and the insulating gasket 35A prevent the electrode terminal 27A from coming into contact with the lid member 6, and the electrode terminal 27A is electrically insulated from the lid member 6 (exterior portion 3). The insulating member 28B and the insulating gasket 35B prevent the electrode terminal 27B from coming into contact with the lid member 6, and the electrode terminal 27B is electrically insulated from the lid member 6 (exterior portion 3).

In the internal cavity 11, the electrode holder 36 is disposed between the electrode group 10 and the lid member 6 in the height direction of the battery 1. The electrode platen (internal insulating member) 36 is formed of an electrically insulating material. The electrode holder 36 has a pair of through holes 37A and 37B. The through holes 37A and 37B are arranged laterally apart from each other. The center of the battery 1 in the lateral direction is located between the through holes 37A and 37B. The through holes 37A and 37B are formed along the height direction of the battery 1 and penetrate the electrode pressing plate 36. The shaft portion 32 of the electrode terminal 27A is inserted into the through hole 37A, and the shaft portion 32 of the electrode terminal 27B is inserted into the through hole 37B.

Fig. 4 shows the structure of the internal cavity 11 of the battery 1 of fig. 1. Fig. 5 shows a cross section taken along line a1-a1 in fig. 4. As shown in fig. 4 and the like, in the internal cavity 11, spaces 38A, 38B are formed on both sides of the electrode group 10 in the lateral direction. A space (first space) 38A is formed between the inner surface of the side wall 9A, which is one of the third and fourth side walls, and the electrode group 10, and a space (second space) 38B is formed between the inner surface of the side wall 9B, which is the other of the third and fourth side walls, and the electrode group 10. That is, the pair of spaces 38A, 38B are formed between the electrode group 10 and the corresponding one of the side walls 9A, 9B, respectively. In the example of fig. 1 to 5, etc., the spaces 38A and 38B are formed between the electrode holder 36 and the bottom wall 7 in the height direction.

The positive electrode collector tabs 21D of the electrode group 10 are confined in the space 38A by welding such as ultrasonic welding. In the space 38A, one or more positive electrode leads such as a spare lead 40A and a lead 41A are disposed. The bundle of positive electrode collector tabs 21D is electrically connected to a positive electrode terminal (for example, 27A) corresponding to one of the electrode terminals 27A and 27B via a positive electrode lead. At this time, the positive electrode lead is connected to the shaft portion 32 of the positive electrode terminal (for example, 27A) in the space 38A. Welding such as ultrasonic welding is used to perform: the connection between the positive electrode collector tabs 21D and the positive electrode leads, the connection between the positive electrode leads, and the connection between the positive electrode leads and the positive electrode terminal (e.g., 27A). Here, the positive electrode lead is formed of a metal having conductivity. The electrode holding plate 36 prevents the positive electrode current collecting tab 21D and the positive electrode lead (e.g., 40A, 41A) from coming into contact with the inner surface of the lid member 6, and the positive electrode current collecting tab 21D and the positive electrode lead (e.g., 40A, 41A) are electrically insulated from the lid member 6.

Similarly, the negative electrode current collecting tab 22D of the electrode group 10 is confined in the space 38B by welding such as ultrasonic welding. In the space 38B, one or more negative electrode leads such as a spare lead 40B and a lead 41B are disposed. The bundle of the negative electrode collector tabs 22D is electrically connected to a negative electrode terminal (for example, 27B) corresponding to one of the electrode terminals 27A and 27B via a negative electrode lead. At this time, the negative electrode lead is connected to the shaft portion 32 of the negative electrode terminal (for example, 27B) in the space 38B. Welding such as ultrasonic welding is used to perform: the connection between the negative electrode collector 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 (e.g., 27B). Here, the negative electrode lead is formed of a metal having conductivity. The electrode holding plate 36 prevents the negative current collecting tab 22D and the negative electrode lead (e.g., 40B, 41B) from coming into contact with the inner surface of the lid member 6, and the negative current collecting tab 22D and the negative electrode lead (e.g., 40B, 41B) are electrically insulated from the lid member 6.

In the example of fig. 1 to 5, the leads 41A and 41B each include a base portion 42 and a pair of extension portions 43. In each of the leads 41A, 41B, the base portion 42 extends in the lateral direction of the battery 1, and abuts against the electrode platen 36 from the side of the bottom wall 7. The leads 41A and 41B are connected to the corresponding one of the electrode terminals 27A and 27B at the base portion 42. In the example of fig. 1 to 5, etc., in each of the leads 41A and 41B, the pair of extending portions 43 extend from the base portion 42 toward the side of the bottom wall 7 in the height direction. Further, in each of the leads 41A, 41B, a pair of extending portions 43 are disposed apart from each other in the longitudinal direction so as to face each other. Therefore, the leads 41A and 41B are formed in a bifurcated shape. The lead 41A is connected to the positive electrode collector tab 21D via a spare lead 40A in the extension portion 43. The lead 41B is connected to the negative electrode current collecting tab 22D via the spare lead 40B in the extending portion 43.

In one example, only one extending portion (e.g., 43) of the leads 41A and 41B may extend from the base portion (e.g., 42) toward the side of the bottom wall 7 in the height direction. In this case, the leads 41A and 41B are connected to the corresponding one of the collector tabs 21D and 22D via the corresponding one of the spare leads 40A and 40B in the extending portion (e.g., 43). In another example, the spare leads 40A and 40B may not be provided. In this case, the leads 41A and 41B are directly connected to the corresponding one of the collector tabs 21D and 22D.

In the example shown in fig. 1 to 5, the lid member 6 is provided with a gas release valve 45 and a liquid inlet 46. The gas release valve 45 and the liquid inlet 46 are disposed between the electrode terminals 27A and 27B in the lateral direction. A sealing plate 47 for closing the pouring port 46 is welded to the outer surface of the lid member 6. The electrode pressing plate 36 has a through hole 48 and an opening hole 49. The through-hole 48 and the opening 49 are formed along the height direction of the battery 1 and penetrate the electrode pressing plate 36. The through hole 48 and the opening hole 49 are arranged between the through holes 37A and 37B in the lateral direction. The electrode platen 36 has a through hole 48 formed at a position facing the liquid inlet 46, and an opening hole 49 formed at a position facing the gas release valve 45.

In the internal cavity 11 of the battery 1, an insulation protector (positive electrode-side insulation protector) 51A is disposed in the space 38A, and an insulation protector (negative electrode-side insulation protector) 51B is disposed in the space 38B. The insulating protector 51A is fixed in the electrode group 10 by an insulating tape 52A, and the insulating protector 51B is fixed in the electrode group 10 by an insulating tape 52B. The insulation guards 51A and 51B and the insulation tapes 52A and 52B are made of electrically insulating materials. The insulating protector 51A is disposed on the inner surface of the outer container 5 in the space 38A, and prevents the positive electrode lead (e.g., 40A, 41A) and the positive electrode current collecting tab 21D from contacting the inner surface of the outer container 5. The insulating protector 51B is disposed on the inner surface of the outer container 5 in the space 38B, and prevents the negative electrode lead (e.g., 40B, 41B) and the negative electrode current collecting tab 22D from coming into contact with the inner surface of the outer container 5. Therefore, the insulating protector 51A electrically insulates the positive electrode lead (e.g., 40A, 41A) and the positive electrode current collecting tab 21D from the inner surface of the outer container 5. The insulating protector 51B electrically insulates the negative electrode lead (e.g., 40B, 41B) and the negative electrode current collecting tab 22D from the inner surface of the outer container 5. In the space 38A, the insulating protector 51A is disposed across the inner surface of the bottom wall 7, the inner surface of the side wall (one of the first side wall and the second side wall) 8A, the inner surface of the side wall (the other of the first side wall and the second side wall) 8B, and the inner surface of the side wall (one of the third side wall and the fourth side wall) 9A. In the space 38B, the insulating protector 51B is disposed across the inner surface of the bottom wall 7, the inner surface of the side wall 8A, the inner surface of the side wall 8B, and the inner surface of the side wall (the other of the third side wall and the fourth side wall) 9B.

Fig. 6 to 9 show the respective configurations of the insulation guards 51A and 51B. As shown in fig. 1 and 4 to 9, each of the insulation guards 51A and 51B includes a guard-side plate portion 61 as one of the first guard-side plate portion and the second guard-side plate portion, and a guard-side plate portion 62 as the other of the first guard-side plate portion and the second guard-side plate portion. The insulation guards 51A and 51B each include a guard side plate 63 as a third guard side plate. The protector side plate portions 61 of the insulation protectors 51A, 51B are disposed on the inner surface of the side wall (one of the first side wall and the second side wall) 8A in the corresponding one of the spaces 38A, 38B. Therefore, the protector side plate portion 61 of each of the insulation protectors 51A, 51B is interposed between the corresponding one of the leads 41A, 41B and the inner surface of the side wall 8A in the longitudinal direction. The protector side plate portions 62 of the insulation protectors 51A, 51B are disposed on the inner surface of the side wall (the other of the first side wall and the second side wall) 8B in the corresponding one of the spaces 38A, 38B. Therefore, the protector side plate portion 62 of each of the insulation protectors 51A, 51B is interposed between the corresponding one of the leads 41A, 41B and the inner surface of the side wall 8B in the longitudinal direction.

The protector side plate portion 63 of the insulation protector 51A is disposed on the inner surface of the side wall (one of the third side wall and the fourth side wall) 9A in the space 38A. Thus, the protector side plate portion 63 of the insulation protector 51A is laterally interposed between the lead wire 41A and the inner surface of the side wall 9A. The protector side plate portion 63 of the insulation protector 51B is disposed on the inner surface of the side wall (the other of the third side wall and the fourth side wall) 9B in the space 38B. Thus, the protector side plate portion 63 of the insulation protector 51B is laterally interposed between the inner surfaces of the side walls 9B of the lead 41B. In each of the insulation guards 51A and 51B, each of the guard-side plate portions 61 to 63 extends in the height direction. In the space 38A, the protector side plate portions 61-63 of the insulating protector 51A extend continuously from the end on the side of the cover member 6 to the end on the side of the bottom wall 7. Similarly, in the space 38B, each of the protector side plate portions 61 to 63 of the insulating protector 51B extends continuously from the end on the side where the cover member 6 is located to the end on the side where the bottom wall 7 is located.

In each of the insulation guards 51A and 51B, a concave shape that is recessed outward in the lateral direction is formed by the guard side plate portions 61 to 63. That is, in each of the insulation guards 51A and 51B, the guard side plate portions 61 to 63 are formed in a concave shape recessed toward the side opposite to the side where the electrode group 10 is located. In the space 38A, the positive electrode current collecting tab 21D and the positive electrode lead (e.g., 40A, 41A) are inserted into the concave portion formed by the protector side plate portions 61 to 63 of the insulating protector 51A. Similarly, in the space 38B, the negative electrode collector tab 22D and the negative electrode lead (e.g., 40B, 41B) are inserted into the concave formed by the guard side plate portions 61 to 63 of the insulating guard 51B.

In the example of fig. 1 and the like, each of the insulation guards 51A and 51B includes a guard bottom plate 64 in addition to the guard side plates 61 to 63 described above. The shield bottom plate portion 64 of each of the insulation shields 51A and 51B is disposed on the inner surface of the bottom wall 7. Therefore, the protector bottom plate portions 64 of the respective insulation protectors 51A, 51B are interposed between the corresponding one of the leads 41A, 41B and the inner surface of the bottom wall 7 in the height direction. In each of the insulation guards 51A and 51B, the guard bottom plate portion 64 is connected to the guard side plate portions 61 to 63 at the end portion on the side of the bottom wall 7. Further, in each of the insulation guards 51A, 51B, the guard bottom plate portion 64 extends from the guard side plate portions 61 to 63 toward the inside in the lateral direction, i.e., toward the side of the electrode group 10 in the lateral direction.

In each of the insulation guards 51A and 51B, a guard projection 65 is formed on the guard bottom plate portion 64. In each of the insulating guards 51A, 51B, the guard protruding portion 65 protrudes toward the side of the electrode group 10 in the lateral direction, that is, toward the inside in the lateral direction, with respect to the guard side plate portions 61, 62. The protector protrusion 65 of each of the insulating protectors 51A, 51B is disposed between the electrode group 10 and the inner surface of the bottom wall 7 in the internal cavity 11. Further, the guard projection 65 of each of the insulating guards 51A, 51B supports the electrode group 10 from the side of the bottom wall 7 in the height direction. That is, the protector projection 65 of each of the insulating protectors 51A, 51B abuts the electrode group 10 from the side of the bottom wall 7. In the example of fig. 4 and the like, the projecting end of the protector projecting portion 65 of the insulation protector 51A is disposed laterally apart from the projecting end of the protector projecting portion 65 of the insulation protector 51B.

Fig. 6 and 7 are perspective views of the insulation protector 51A (51B) viewed from different directions from each other. Fig. 8 shows the insulating protector 51A (51B) as viewed from the side from which the protector protruding portion 65 protrudes. Fig. 9 shows the insulating protector 51A (51B) in a state of being viewed from the outer surface of the protector side plate portion (one of the first protector side plate portion and the second protector side plate portion) 61 toward the side.

In each of the insulation guards 51A and 51B, the guard bottom plate portion 64 includes a guard bottom surface 66 facing the bottom wall 7. The shield bottom surface 66 of each of the insulation shields 51A, 51B faces the inner surface of the bottom wall 7. In the protector bottom surface 66 of each of the insulation protectors 51A, 51B, an inclined surface 67 is formed as one of the first inclined surface and the second inclined surface, and an inclined surface 68 is formed as the other of the first inclined surface and the second inclined surface. In the protector bottom surface 66 of each of the insulation protectors 51A, 51B, a rim on the side where the side wall (one of the first side wall and the second side wall) 8A is located is formed by the inclined surface 67. In the protector bottom surface 66 of each of the insulation protectors 51A, 51B, an edge on the side where the side wall (the other of the first side wall and the second side wall) 8B is located is formed by the inclined surface 68. In the example of fig. 1, 4, and the like, in the insulation guards 51A, 51B, the inclined surfaces 67, 68 extend in the projecting direction of the guard projecting portion 65, that is, in the lateral direction. In the shield bottom plate portion 64 of each of the insulation shields 51A and 51B, the inclined surfaces 67 and 68 extend continuously over the entire length or substantially the entire length in the lateral direction.

The inclined surface 67 is inclined in a state of being apart from the bottom wall 7 in the height direction as approaching the side wall 8A in the longitudinal direction. Further, the inclined surface 68 is inclined in a state of being apart from the bottom wall 7 in the height direction as approaching the side wall 8B in the longitudinal direction. Therefore, in each of the insulation guards 51A, 51B, each of the inclined surfaces 67, 68 is inclined in a state of being apart from the bottom wall 7 in the height direction as going toward the outside in the longitudinal direction.

In the example shown in fig. 1, 4, and the like, the inclined surfaces 67 and 68 of the insulation guards 51A and 51B are formed in inclined curved surfaces. In each of the insulation guards 51A and 51B, each of the inclined surfaces 67 and 68 has an arc shape or a substantially arc shape in a cross section perpendicular or substantially perpendicular to the projecting direction of the guard projecting portion 65 (the lateral direction of the battery 1). However, in one example, the inclined surfaces 67 and 68 may be formed in an inclined plane shape in the insulation guards 51A and 51B. In this case, in each of the insulation guards 51A, 51B, each of the inclined surfaces 67, 68 is inclined in a state of being apart from the bottom wall 7 in the height direction as going toward the outside in the longitudinal direction.

In the battery 1, two protrusions 71 are provided as one of the first protrusion and the second protrusion, and two protrusions 72 are provided as the other of the first protrusion and the second protrusion. Each projection 71 is connected to a corresponding one of the insulation guards 51A, 51B, and projects from the corresponding one of the insulation guards 51A, 51B. In the example of fig. 1 and the like, one projection 71 projects from each of the insulation guards 51A and 51B. Each projection 72 is connected to a corresponding one of the insulation guards 51A and 51B, and projects from the corresponding one of the insulation guards 51A and 51B. In the example of fig. 1 and the like, one projection 72 projects from each of the insulation guards 51A and 51B.

Each projection 71 projects from the corresponding one of the insulation guards 51A and 51B toward the boundary portion between the side wall (one of the first side wall and the second side wall) 8A and the bottom wall 7. The projecting end of each projection 71 abuts on the boundary portion between the side wall 8A and the bottom wall 7. That is, the projecting end of each projection 71 abuts on a corner (edge) between the side wall 8A and the bottom wall 7. Further, each of the projections 72 projects from the corresponding one of the insulation guards 51A and 51B toward a boundary portion between the side wall (the other of the first side wall and the second side wall) 8B and the bottom wall 7. The projecting end of each projection 72 abuts on the boundary portion between the side wall 8B and the bottom wall 7. That is, the projecting end of each projection 72 abuts on a corner (edge) between the side wall 8B and the bottom wall 7.

In the example of fig. 1, 4, and 5, each of the projections 71 and 72 is formed integrally with the corresponding one of the insulation guards 51A and 51B and is formed of an electrically insulating material. Each of the projections 71 projects from the corresponding one of the insulation guards 51A and 51B in the longitudinal direction toward the side wall 8A. Each projection 72 projects from the corresponding one of the insulation guards 51A and 51B toward the side wall 8B in the longitudinal direction. Therefore, the respective projections 71, 72 project outward in the longitudinal direction from the corresponding one of the insulation guards 51A, 51B.

In each of the insulation guards 51A and 51B, the projection 71 projects from the guard projecting portion 65 of the guard bottom plate portion 64 toward the boundary portion between the side wall 8A and the bottom wall 7. Further, in each of the insulation guards 51A, 51B, the protrusion 72 protrudes from the guard protruding portion 65 of the guard bottom plate portion 64 toward the boundary portion between the side wall 8B and the bottom wall 7. In each of the insulation guards 51A and 51B, the protrusion 71 protrudes from the inclined surface (one of the first inclined surface and the second inclined surface) 67 of the guard bottom surface 66 toward the boundary between the side wall 8A and the bottom wall 7. In each of the insulation guards 51A and 51B, the protrusion 72 protrudes from the inclined surface (the other of the first inclined surface and the second inclined surface) 68 of the guard bottom surface 66 toward the boundary between the side wall 8B and the bottom wall 7.

In the examples of fig. 1, 4, 5, and the like, the projections 71 and 72 are formed in a plate shape. The width direction of each of the plate-shaped projections 71, 72 is along the lateral direction of the battery 1, and the thickness direction of each of the plate-shaped projections 71, 72 is along the height direction of the battery 1. In one example, the projections 71 and 72 are formed in a plate shape having a thickness of about 0.5 mm. Each projection 71 is disposed between the inclined surface 67 of the corresponding one of the insulation guards 51A and 51B and the inner surface of the bottom wall 7 in the height direction. Further, a gap is formed between each protrusion 71 and the corresponding one of the inclined surfaces 67 of the insulation guards 51A and 51B. Each of the projections 72 is disposed between the inclined surface 68 of the corresponding one of the insulation guards 51A and 51B and the inner surface of the bottom wall 7 in the height direction. Further, a gap is formed between each protrusion 72 and the corresponding one of the inclined surfaces 68 of the insulation guards 51A and 51B. Since the projections 71 and 72 are formed as described above, the projections 71 and 72 can be elastically deformed.

Next, the operation and effect of the battery 1 of the present embodiment will be described. In the battery 1, the internal components accommodated in the internal cavity 11 of the electrode group 10 and the like are constrained by the peripheral wall 4 of the outer container 5 and the like. For example, the movement of the built-in components such as the electrode group 10 in the longitudinal direction is restricted by the side walls (first and second side walls) 8A and 8B. The influence of external impact on the built-in objects including the electrode group 10, the current collecting tabs 21D, 22D, the leads 40A, 40B, 41A, 41B, and the insulation guards 51A, 51B can be suppressed by restraining the built-in objects.

When the battery 1 is used, gas is generated from the electrode group 10 in the internal cavity 11. The outer container 5 is inflated by the gas generated in the internal cavity 11. Here, in the battery 1, the area of the outer surface of each of the side walls 8A, 8B is much larger than the area of the outer surface of each of the bottom wall 7, the side walls 9A, 9B, and the lid member 6. Therefore, the gas generated in the internal cavity 11 expands the side walls 8A and 8B outward. In particular, when the battery 1 is large, the expansion amount of each of the side walls 8A and 8B is large due to gas generation.

Fig. 10 shows a state in which the side walls (long side walls) 8A and 8B are expanded by the gas generated in the internal cavity 11. As shown in fig. 10, when gas is generated, the side walls 8A and 8B largely expand at the center in the height direction. Therefore, the sidewalls 8A and 8B have a gap between the electrode group 10 and the central portion in the height direction, and do not restrict the electrode group 10. However, even if the side walls 8A and 8B expand due to the gas generation, the end portion of the side wall 8A on the side of the bottom wall 7 does not expand or does not substantially expand. Likewise, the end of the side wall 8B on the side of the bottom wall 7 is also not expanded, or is not substantially expanded. That is, even if gas is generated in the internal cavity 11, the boundary portion (corner portion) between the side wall 8A and the bottom wall 7 and the vicinity thereof, and the boundary portion (corner portion) between the side wall 8B and the bottom wall 7 and the vicinity thereof do not expand or substantially do not expand.

Since the boundary portion (corner portion) between the side wall 8A and the bottom wall 7 and the vicinity thereof do not expand or substantially do not expand, even if gas is generated in the internal cavity 11, the projecting end of each projection 71 abuts against the boundary portion between the side wall 8A and the bottom wall 7. Similarly, since the boundary portion (corner portion) between the side wall 8B and the bottom wall 7 and the vicinity thereof do not expand or substantially do not expand, even if gas is generated in the internal cavity 11, the projecting end of each projection 72 abuts on the boundary portion between the side wall 8B and the bottom wall 7. Here, the projections 71 and 72 are connected to the corresponding one of the insulation guards 51A and 51B, and are formed integrally with the corresponding one of the insulation guards 51A and 51B in the present embodiment. The insulating guards 51A and 51B are attached to the electrode group 10. Since each projection 71 abuts on the boundary portion between the side wall 8A and the bottom wall 7 and the projecting end of each projection 72 abuts on the boundary portion between the side wall 8B and the bottom wall 7, the movement of the built-in components such as the electrode group 10 and the insulation guards 51A and 51B in the longitudinal direction is restricted.

As described above, by providing the projections 71 and 72, even if gas is generated in the internal cavity 11, the movement of the built-in object such as the electrode group 10 in the longitudinal direction can be restrained. That is, even if the outer container 5 expands due to the gas generation, the built-in components can be restrained appropriately. Thus, even if gas is generated, the influence of external impact on the internal components including the electrode group 10, the current collecting tabs 21D, 22D, the leads 40A, 40B, 41A, 41B, and the insulation guards 51A, 51B can be suppressed. The impact of external impact on the built-in object is suppressed, so that the damage of the built-in object caused by the external impact is prevented, and the durability of the built-in object is improved.

In the present embodiment, in the respective insulation guards 51A and 51B, the projections 71 and 72 project from the guard projection 65. The protector projection 65 of each of the insulating protectors 51A, 51B is disposed between the electrode group 10 and the inner surface of the bottom wall 7, and supports the electrode group 10 from the side of the bottom wall 7 in the height direction. In each of the insulating guards 51A and 51B, since the projections 71 and 72 are connected to the guard projection 65 that supports the electrode group 10, the movement of the electrode group 10 (built-in object) in the longitudinal direction can be restrained more reliably by the projections 71 and 72.

In addition, when the battery 1 is manufactured, the electrode terminals 27A, 27B, the insulating members 28A, 28B, the insulating gaskets 35A, 35B, and the electrode pressure plate 36 are mounted on the lid member 6. The collector tabs 21D and 22D of the electrode group 10 are connected to the corresponding one of the electrode terminals 27A and 27B via the corresponding one of the positive electrode leads (e.g., 40A and 41A) and the negative electrode leads (e.g., 40B and 41B). Then, the respective insulation guards 51A and 51B are attached (fixed) to the electrode group 10 via the corresponding one of the insulation tapes 52A and 52B. In a state where the electrode group 10, the insulating guards 51A and 51B, the lid member 6, and the like are assembled as described above, the internal member including the electrode group 10, the current collecting tabs 21D and 22D, the leads 40A, 40B, 41A and 41B, and the insulating guards 51A and 51B is inserted into the internal cavity 11 of the outer container 5. Then, the lid member 6 is welded to the end portion of the peripheral wall 4 opposite to the bottom wall 7 in a state where the content is inserted into the internal cavity 11, and the lid member 6 is attached to the peripheral wall 4 of the outer container 5.

Fig. 11 shows a state in which the electrode group 10 and other internal components are inserted into the internal cavity 11 when the battery 1 is manufactured. As shown in fig. 11, when the built-in object is inserted into the internal cavity 11, the projections 71 abut against the side wall 8A, and the projections 72 abut against the side wall 8B. In the present embodiment, the projections 71 and 72 are formed in a plate shape so as to project from the corresponding one of the insulation guards 51A and 51B. Therefore, each projection 71 is elastically deformed by the pressing force from the side wall 8A when each projection 71 abuts against the side wall 8A. Similarly, each projection 72 is elastically deformed by the pressing force from the side wall 8B when each projection 72 abuts against the side wall 8B. In a state where the built-in object is inserted into the internal cavity 11, the protrusions 71 and 72 are elastically deformed, so that the built-in object can be easily inserted into the internal cavity 11. Therefore, the insertability of the built-in object into the internal cavity 11 can be ensured at the time of manufacturing the battery 1.

In the present embodiment, the inclined surfaces 67 and 68 are formed on the protector bottom surface 66 in the insulation protectors 51A and 51B. Therefore, in a state where the built-in object is inserted into the internal cavity 11, friction between the insulation guards 51A and 51B and the peripheral wall 4 (the side walls 8A and 8B) can be reduced. This improves the insertability of the built-in object into the internal cavity 11 when the battery 1 is manufactured.

(modification example)

In the above-described embodiments and the like, the projections 71 and 72 are formed in a plate shape whose width direction is along the lateral direction of the battery 1, but the present invention is not limited to this. In one modification, each of the projections 71 and 72 may be formed in a columnar shape (rod shape). For example, in the first modification shown in fig. 12, each of the projections 71, 72 is formed in a cylindrical shape extending in the longitudinal direction of the battery 1. In the present modification, the respective projections 71, 72 project outward in the longitudinal direction from the corresponding one of the insulation guards 51A, 51B. The projecting end of each projection 71 abuts on the boundary portion between the sidewall 8A and the bottom wall 7, and the projecting end of each projection 72 abuts on the boundary portion between the sidewall 8B and the bottom wall 7.

In the second modification shown in fig. 13, each protrusion 71 is bent at a bent position E1 of the projecting end portion. Then, each protrusion 72 is bent at a bent position E2 of the protruding end portion. Each projection 71 extends in the projecting direction from the corresponding one of the insulating guards 51A, 51B to the bent position E1, and extends toward the outside in the longitudinal direction of the battery 1. Likewise, each protrusion 72 extends in the protruding direction from the corresponding one of the insulating guards 51A, 51B to the bent position E2, and extends toward the outside in the longitudinal direction of the battery 1. Further, each protrusion 71 is bent toward the side of the cover member 6 in the height direction at the bent position E1. Likewise, each protrusion 72 is bent toward the side of the cover member 6 in the height direction at the bent position E2. In the present modification, too, the projecting end of each projection 71 abuts on the boundary portion between the sidewall 8A and the bottom wall 7, and the projecting end of each projection 72 abuts on the boundary portion between the sidewall 8B and the bottom wall 7.

In the above-described embodiments and the like, the respective projections 71 and 72 project outward in the longitudinal direction from the corresponding one of the insulation guards 51A and 51B, but the present invention is not limited to this. For example, in a third modification shown in fig. 14, the projections 71 and 72 project from the corresponding one of the insulation guards 51A and 51B toward the side of the bottom wall 7 in the height direction. In the present modification, the projections 71 and 72 are formed in a plate shape, and the width direction of each of the plate-shaped projections 71 and 72 is along the lateral direction of the battery 1. The thickness direction of each of the plate-shaped projections 71, 72 is along the longitudinal direction of the battery 1. In the present modification, too, the projecting end of each projection 71 abuts on the boundary portion between the sidewall 8A and the bottom wall 7, and the projecting end of each projection 72 abuts on the boundary portion between the sidewall 8B and the bottom wall 7. Therefore, the present modification also achieves the same operation and effect as those of the above-described embodiment and the like.

In one modification, as in the third modification, the projections 71 and 72 project from the corresponding one of the insulation guards 51A and 51B toward the bottom wall 7 in the height direction. However, in the present modification, each of the projections 71 and 72 is formed in a columnar shape (rod shape) such as a columnar shape. In the present modification, too, the projecting end of each projection 71 abuts on the boundary portion between the sidewall 8A and the bottom wall 7, and the projecting end of each projection 72 abuts on the boundary portion between the sidewall 8B and the bottom wall 7.

In another modification, as in the third modification, the projections 71 and 72 project from the corresponding one of the insulation guards 51A and 51B toward the bottom wall 7 in the height direction. The projections 71 and 72 are bent at the bent positions of the projecting end portions. Each of the projections 71, 72 extends in the protruding direction from the corresponding one of the insulation guards 51A, 51B to the bent position, and extends toward the side of the bottom wall 7 in the height direction of the battery 1. Further, the projections 71 and 72 are bent inward in the longitudinal direction at the bent positions. In the present modification, too, the projecting end of each projection 71 abuts on the boundary portion between the sidewall 8A and the bottom wall 7, and the projecting end of each projection 72 abuts on the boundary portion between the sidewall 8B and the bottom wall 7.

In the above embodiment, the projections 71 and 72 are formed integrally with the corresponding one of the insulation guards 51A and 51B, but the present invention is not limited thereto. In one modification, the projections 71 and 72 are coupled to the corresponding one of the insulation guards 51A and 51B. In the present modification, the projections 71 and 72 are connected to the corresponding one of the insulation guards 51A and 51B and project from the corresponding one of the insulation guards 51A and 51B. The projecting end of each projection 71 abuts on the boundary portion between the sidewall 8A and the bottom wall 7, and the projecting end of each projection 72 abuts on the boundary portion between the sidewall 8B and the bottom wall 7.

In one modification, the projections 71 and 72 are connected to the corresponding one of the insulation guards 51A and 51B and are formed of metal. That is, the projections 71 and 72 need not be formed of a material having electrical insulation. In this case, too, the insulation guards 51A and 51B are made of a material having electrical insulation properties.

In the above-described embodiments and the like, one projection 71 and 72 projects from the insulating protector 51A, and one projection 71 and 72 projects from the insulating protector 51B, but the present invention is not limited to this. That is, at least one of the projections 71 and 72 may protrude from the insulation shield 51A in plural, or at least one of the projections 71 and 72 may protrude from the insulation shield 51B in plural. In one modification, two or more projections 71 and two or more projections 72 project from the insulation shield 51A. In another modification, two or more projections 71 and two or more projections 72 project from the insulation shield 51B.

In the above-described embodiments and the like, the projections 71 and 72 project from the two insulation guards 51A and 51B, respectively, but the present invention is not limited thereto. That is, the projections 71 and 72 may project from only one of the insulation guards 51A and 51B. In one modification, each of the projections 71, 72 projects only from the insulation shield 51A. In this case, there is no provision for: a projection projecting from insulation guard 51B toward the boundary portion between side wall 8A and bottom wall 7, and a projection projecting from insulation guard 51B toward the boundary portion between side wall 8B and bottom wall 7. In another modification, each of the projections 71, 72 projects only from the insulation shield 51B. In this case, there is no provision for: a projection projecting from insulation guard 51A toward the boundary portion between side wall 8A and bottom wall 7, and a projection projecting from insulation guard 51A toward the boundary portion between side wall 8B and bottom wall 7.

In addition, in another modification, projection 71 projects only from insulation shield 51A, and projection 72 projects only from insulation shield 51B. In this case, there is no provision for: a projection projecting from insulation guard 51B toward the boundary portion between side wall 8A and bottom wall 7, and a projection projecting from insulation guard 51A toward the boundary portion between side wall 8B and bottom wall 7. In another variation, projection 71 projects only from insulation shield 51B and projection 72 projects only from insulation shield 51A. In this case, there is no provision for: a projection projecting from insulation guard 51A toward the boundary portion between side wall 8A and bottom wall 7, and a projection projecting from insulation guard 51B toward the boundary portion between side wall 8B and bottom wall 7.

(Battery pack)

Next, a battery pack using the battery of the above embodiment and the like will be described. Fig. 15 shows an example of a battery pack 80 using the battery 1 according to the embodiment of fig. 1 to 14. In an example of fig. 15 and the like, a battery module 75 is formed by a plurality of batteries 1. In the battery module 75, a plurality of batteries 1 are electrically connected in series. The cells 1 are electrically connected to each other via bus bars (not shown) or the like. In another example, in the battery module 75, a plurality of batteries 1 may be connected in parallel in a circuit. In another example, the battery module 75 may be provided with 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.

In the battery module 75 of the battery pack 80, the positive electrode terminal (for example, 27A) of a corresponding one of the plurality of batteries 1 is connected to the positive electrode-side module terminal 91 via a positive electrode-side lead 93 or the like. In a corresponding one of the plurality of batteries 1 different from the battery 1 connected to the positive electrode lead 93, the negative electrode terminal (for example, 27B) is connected to the module terminal 92 on the negative electrode side via the negative electrode lead 94.

The battery pack 80 is provided with a printed wiring board 81. A protection circuit 82, a thermistor 83 as a temperature detector, and an external terminal 85 for energization are mounted on the printed wiring board 81. In the battery pack 80, unnecessary connection between the electrical paths on the printed wiring board 81 and the wiring of the battery module 75 is prevented by an insulating member (not shown). The positive-side module terminal 91 is connected to the protection circuit 82 via a wire 86 or the like formed on the printed wiring board 81, and the negative-side module terminal 92 is connected to the protection circuit 82 via a wire 87 or the like formed on the printed wiring board 81.

The thermistor 83 serving as a temperature detector detects the temperature of each of the plurality of batteries 1 forming the battery module 75. The thermistor 83 outputs a temperature detection signal to the protection circuit 82.

The battery pack 80 has a current detection function and a voltage detection function. In the assembled battery 80, an input current to the battery module 75 and an output current of the battery module 75 may be detected, or a current flowing through any one of the plurality of batteries 1 forming the battery module 75 may be detected. In the assembled battery 80, the voltage of each battery 1 may be detected in the battery module 75, or the voltage applied to the entire battery module 75 may be detected. In the battery pack 80, the battery module 75 and the protection circuit 82 are connected to each other via a wire 84. The detection signal regarding the current and the detection signal regarding the voltage are output to the protection circuit 82 via the wiring 84.

In one example, the positive electrode potential or the negative electrode potential is detected for each battery 1 forming the battery module 75 instead of detecting the voltage of each battery 1. In this case, a lithium electrode or the like is provided as a reference electrode on the battery module 75. Then, the positive electrode potential or the negative electrode potential of each battery 1 is detected with reference to the potential of the reference electrode.

The external terminal 85 is connected to a device external to the battery pack 80. The external terminal 85 is used for: the current of the battery module 75 is output to the outside, and/or the current is input to the battery module 75. When the battery module 75 of the battery pack 80 is used as a power source, a current is supplied to the outside of the battery pack 80 through the external terminal 85 for energization. When the battery module 75 is charged, a charging current is supplied to the battery module 75 through the external terminal 85 for energization. The charging current of the battery module 75 includes, for example, regenerative energy of motive power of a vehicle or the like. The protection circuit 82 can be connected to the external terminal 85 via a positive wiring 88 and a negative wiring 89.

The protection circuit 82 has a function of being able to interrupt the electrical connection between the battery module 75 and the external terminal 85. The protection circuit 82 is provided with a relay, a fuse, or the like as a connection blocking portion. The protection circuit 82 has a function of controlling charging and discharging of the battery module 75. The protection circuit 82 controls charging and discharging of the battery module 75 based on the detection result regarding any of the current, voltage, temperature, and the like described above.

For example, when the temperature detected by the thermistor 83 is equal to or higher than a predetermined temperature, the protection circuit 82 determines that a predetermined condition is met. When any of overcharge, overdischarge, overcurrent, and the like is detected in the battery module 75, the protection circuit 82 determines that the battery module 75 has reached a predetermined condition. When it is determined that the battery module 75 has reached the predetermined condition, the protection circuit 82 can interrupt the conduction between the protection circuit 82 and the external terminal 85 for conduction. By interrupting the conduction between the protection circuit 82 and the external terminal 85 for conduction, the output of the current to the outside of the battery module 75 and the input of the current to the battery module 75 are stopped. This effectively prevents the battery module 75 from continuously generating an overcurrent.

In one example, a circuit formed in a device using the battery pack 80 (battery module 75) as a power source may be used as the protection circuit. Instead of the battery module 75 formed of a plurality of batteries 1, only a single battery 1 may be provided in the battery pack 80. In addition, a plurality of battery modules 75 may be provided in the battery pack 80, and the battery modules 75 may be electrically connected in series and/or parallel with each other.

(use of Battery pack)

The structure of the battery pack 80 including one or more batteries 1 may be appropriately changed depending on the application. The battery pack 80 is preferably used in a device that requires charging and discharging with a large current. Specific applications of the battery pack 80 include use as a power source for a digital camera, use in a vehicle, and use in a stationary place. In this case, examples of the vehicle to which the battery pack 80 is attached include a two-to-four-wheeled hybrid electric vehicle, a two-to-four-wheeled electric vehicle, a power-assisted bicycle, a railway vehicle, a forklift truck, and the like.

Fig. 16 shows an example of the application to a vehicle 100 as an example of the application of the battery pack 80. In the example shown in fig. 16, a vehicle 100 includes a vehicle body 101 and a battery pack 80. In the example shown in fig. 16, the vehicle 100 is a four-wheeled automobile. Further, the vehicle 100 may be equipped with a plurality of battery packs 80.

In the example of fig. 16, the battery pack 80 is mounted in an engine room located in front of the vehicle body 101. The battery pack 80 may be mounted on the rear side of the vehicle body 101 or under a seat, for example. In particular, the battery pack 80 including one or more batteries 1 can be disposed in a narrow space below a seat. As described above, the battery pack 80 can be used as a power source of the vehicle 100. In addition, the assembled battery 80 can recover regenerative energy of motive power of the vehicle 100.

In the battery 1 mounted on the vehicle 100 or the like, as described above, since the influence of the external impact on the built-in object accommodated in the internal cavity 11 is suppressed, the damage of the external impact on the built-in object can be prevented, and the durability of the built-in object can be improved. Therefore, even when an external impact is generated by the traveling vibration of the vehicle 100, it is possible to suppress the influence of the external impact and prevent damage to the built-in object housed in the internal cavity 11 by the external impact.

According to at least one embodiment or example thereof, the first and second protrusions are connected to and protrude from the insulation shield, respectively. The protruding end of the first protrusion abuts against the boundary portion between the first sidewall and the bottom wall, and the protruding end of the second protrusion abuts against the boundary portion between the second sidewall and the bottom wall. Thus, even if the outer container swells, the battery can be provided in which the internal member can be appropriately restrained in the internal cavity and the insertion of the internal member into the internal cavity can be ensured during the production.

Although several embodiments of the present invention have been described above, these embodiments are merely examples and do not limit the scope of the present invention. These new embodiments can be implemented in other various ways, and various omissions, substitutions, and changes can be made without departing from the spirit of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention recited in the patent claims and the equivalent scope thereof.