Battery

Abstract

A battery in which an electrode laminate is provided inside an exterior body, an end-face positive electrode current collector is disposed on one surface in the lamination direction of the electrode laminate, an end-face negative electrode current collector is disposed on the other surface in the lamination direction of the electrode laminate, and an internal current collector is laminated inside the electrode laminate. The internal current collector has a connection part, a positive electrode terminal disposed therein, a negative electrode terminal disposed therein, and a connection terminal disposed therein, the end-face positive electrode current collector and the positive electrode terminal are electrically connected inside the exterior body, the end-face negative electrode current collector and the negative electrode terminal are electrically connected, and the connection part and the connection terminal are electrically connected.

Description

Technical Field

[0001] The present application relates to batteries. Background Art

[0002] Japanese Patent Publication No. 2019-53845 discloses a collector plate configuration structure for a bipolar battery, wherein a voltage monitoring terminal (collector plate) extends along the stacking direction on the outer surface of a side wall sealing material or between a battery cell stack and a side wall sealing material, and its end is configured on the upper surface of an upper wall sealing material. According to Japanese Patent Publication No. 2019-53845, it is recorded that by configuring the voltage monitoring terminal on the upper surface of the upper wall sealing material, the exclusive area of ​​the voltage monitoring terminal in the side surface of the cell can be suppressed. Summary of the invention

[0003] However, in the collector plate configuration structure of Japanese Patent Application Laid-Open No. 2019-53845, a through hole is provided in the exterior member, from which electrodes and voltage monitoring terminals are led out to the outside, so there is room for improvement in improving airtightness and gas barrier properties.

[0004] Therefore, in view of the above circumstances, a main object of the present disclosure is to provide a battery capable of improving airtightness, gas barrier properties, and improving construction efficiency.

[0005] The present disclosure provides at least the following aspects.

[0006] The first method provides a battery, comprising an electrode stack inside an outer casing, wherein an end face positive electrode collector is arranged on one surface of the electrode stack in the stacking direction, an end face negative electrode collector is arranged on the other surface of the electrode stack in the stacking direction, an internal collector is stacked inside the electrode stack, the internal collector has a connecting portion extending from a side surface of the electrode stack, a positive terminal is arranged on one surface of the outer casing in the stacking direction, a negative terminal is arranged on the other surface of the outer casing in the stacking direction, a connecting terminal is arranged on the same surface as at least one of the positive terminal and the negative terminal, and inside the outer casing, the end face positive electrode collector and the positive terminal are electrically connected, the end face negative electrode collector and the negative terminal are electrically connected, and the connecting portion and the connecting terminal are electrically connected.

[0007] A second aspect is a battery according to the first aspect, wherein the outer casing is made of metal, and the connection terminal includes a through hole penetrating an end surface of the outer casing in the stacking direction, a metal portion disposed in the through hole, and an insulating layer disposed between the through hole and the metal portion.

[0008] A third aspect is the battery according to the second aspect, wherein the insulating layer is disposed inside the through hole and inside and outside peripheral portions of the exterior body that are continuous from the through hole.

[0009] A fourth aspect is the battery according to any one of the first to third aspects, wherein inside the outer casing, each end surface current collector and each electrode terminal are in direct contact with each other, and the connection portion and the connection terminal are in direct contact with each other.

[0010] According to the battery of the present disclosure, airtightness and gas barrier properties can be improved, and structural efficiency can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, in which like reference numerals represent like elements, and in which:

[0012] Figure 1 is a top view of the battery 100 .

[0013] Figure 2A So Figure 1 FIG. 1 is a cross-sectional view of the battery 100 cut along line II-II.

[0014] Figure 2B is an exploded cross-sectional view of the battery 100 .

[0015] Figure 3 It is a plan view of the electrode stack 50 .

[0016] Figure 4A is from Figure 3 A front view of the electrode stack 50 as viewed from the direction A.

[0017] Figure 4B is from Figure 3 A side view of the electrode stack 50 as viewed from the B direction.

[0018] Figure 5A It is a top view of the internal current collector 20 .

[0019] Figure 5B The diagram shows a plurality of internal current collectors 20 for explaining the differences in the positions and lengths of the connecting portions 22 .

[0020] Figure 6 2 is a cross-sectional view of an electrode stack 50 as an example.

[0021] Figure 7 This is a partial cross-sectional view focusing on the connection terminal 70 .

[0022] Figure 8 1 is a diagram showing an example of a method of providing the connection terminal 70 to the exterior body 90 . DETAILED DESCRIPTION

[0023] The battery of the present disclosure will be described using the battery 100 as one embodiment.

[0024] Figure 1 A top view of the battery 100 is shown. Figure 2A Shown with Figure 1 A cross-sectional view of the battery 100 cut along line II-II, Figure 2B The exploded cross-sectional view is shown. Figure 1 , Figure 2A , Figure 2B As shown, the battery 100 includes an electrode stack 50 and an exterior body 90 , and the electrode stack 50 is provided inside the exterior body 90 .

[0025] <Electrode Laminate 50>

[0026] First, the electrode stack 50 will be described. Figure 3 A top view of the electrode stack 50 is shown. Figure 4A Shown from Figure 3 A front view of the electrode stack 50 viewed from the direction A, Figure 4B Shown from Figure 3 A side view of the electrode stack 50 as viewed from the B direction.

[0027] The electrode stack 50 has a rectangular shape when observed in the stacking direction, and is a stack including a collector (a positive electrode collector and a negative electrode collector), a positive electrode layer, a negative electrode layer, and an electrolyte layer. In the electrode stack 50, the number of stacking layers of each layer is not particularly limited and can be appropriately set according to the purpose. The stacking method of the electrode stack 50 is not particularly limited, and it can be either a monopolar type or a bipolar type. The electrode stack 50 can be either a liquid battery or a solid battery. The electrode stack 50 can be either a lithium ion battery, a sodium ion battery, or a nickel-hydrogen battery, etc. The electrode stack 50 can be either a primary battery or a secondary battery.

[0028] (Material of Electrode Stack 50)

[0029] The material of each layer constituting the electrode stack 50 will be described with reference to a typical example. However, the material of each layer constituting the electrode stack 50 is not limited thereto.

[0030] The current collector is a sheet-shaped conductive component. Examples of the current collector include metal foils of stainless steel, iron, copper, aluminum, titanium, nickel, and the like. The metal foil may also be composed of an alloy containing two or more of these metals. In addition, the metal foil may also be subjected to a predetermined surface treatment such as plating. The current collector may also be composed of a plurality of metal foils. In this case, the metal foils may be joined with an adhesive or the like, or by stamping or the like. The shape of the current collector may be rectangular. The thickness of the current collector is not particularly limited, and is, for example, 1 μm to 1 mm.

[0031] The positive electrode layer contains at least a positive electrode active material. The positive electrode active material is not particularly limited and can be appropriately selected from any material according to the intended battery performance. For example, composite oxides, metallic lithium, and sulfur can be cited. In the composition of the composite oxide, for example, at least one of iron, manganese, titanium, nickel, cobalt, and aluminum and lithium are included. In the example of the composite oxide, olivine-type lithium iron phosphate (LiFePO4) can be cited.

[0032] The positive electrode layer may also contain a conductive additive. The conductive additive is not particularly limited and can be appropriately selected from any material according to the desired battery performance. For example, carbon materials such as acetylene black, carbon black, and graphite can be cited.

[0033] The positive electrode layer may also contain an adhesive. The adhesive is not particularly limited and may be appropriately selected from any material according to the desired battery performance. For example, rubber-based resins, fluoride-based resins, etc. may be cited.

[0034] The positive electrode layer may also contain a solid electrolyte. The solid electrolyte is not particularly limited and can be appropriately selected from any material according to the desired battery performance. For example, oxide solid electrolytes, sulfide solid electrolytes, etc. can be cited.

[0035] The positive electrode layer may be rectangular in shape. The thickness of the positive electrode layer is not particularly limited, and is, for example, in the range of 1 μm to 1 mm. The area of ​​the positive electrode layer may be smaller than that of the negative electrode layer. The content of each material in the positive electrode layer is not particularly limited, and may be appropriately set according to the intended battery performance. In addition, the positive electrode layer may also contain materials other than the above-mentioned materials.

[0036] The negative electrode layer contains a negative electrode active material. The negative electrode active material is not particularly limited and can be appropriately selected from any material according to the battery performance of the purpose. For example, carbon materials such as graphite, artificial graphite, hard carbon, soft carbon, metal compounds, elements that can be alloyed with lithium or their compounds, etc. can be cited. Examples of elements that can be alloyed with lithium include silicon and tin.

[0037] The negative electrode layer may also contain a conductive aid. The conductive aid is not particularly limited and can be appropriately selected from any material according to the desired battery performance. For example, it can be appropriately selected from conductive aids that can be applied to the positive electrode layer.

[0038] The negative electrode layer may also contain an adhesive. The adhesive is not particularly limited and may be appropriately selected from any material according to the intended battery performance. For example, it may be appropriately selected from adhesives applicable to the positive electrode layer.

[0039] The negative electrode layer may also contain a solid electrolyte. The solid electrolyte is not particularly limited and can be appropriately selected from any material according to the desired battery performance. For example, it can be appropriately selected from solid electrolytes that can be applied to the positive electrode layer.

[0040] The negative electrode layer may be rectangular in shape. The thickness of the negative electrode layer is not particularly limited, and is, for example, in the range of 1 μm to 1 mm. The area of ​​the negative electrode layer may be larger than the positive electrode layer from the perspective of increasing output. The content of each material in the negative electrode layer is not particularly limited and may be appropriately set according to the intended battery performance. In addition, the negative electrode layer may also contain materials other than the above-mentioned materials.

[0041] In the case where the electrolyte layer is a liquid electrolyte layer, the electrolyte layer includes a separator and an electrolyte. The separator is mainly a porous sheet of a polyolefin system. The electrolyte is formed by dissolving a supporting electrolyte into a non-aqueous solvent. As non-aqueous solvents, carbonates, ethers, esters, etc. can be cited. For example, supporting electrolytes can include LiPF6, LiBF4, lithium bis(fluorosulfonyl)imide (LiFSI), lithium bis(trifluoromethane)sulfonylimide (LiTFSI), etc.

[0042] When the electrolyte layer is a solid electrolyte layer, the electrolyte layer contains a solid electrolyte. In addition, the solid electrolyte layer may also contain a binder. The solid electrolyte and the binder can be appropriately selected from the above-mentioned solid electrolytes and binders.

[0043] The electrolyte layer may be in a rectangular shape. The thickness of the electrolyte layer is not particularly limited, and is, for example, in the range of 1 μm to 1 mm.

[0044] (End surface positive electrode current collector 11, end surface negative electrode current collector 12, internal current collector 20)

[0045] like Figure 3 , Figure 4A , Figure 4B It is described that the electrode stack 50 includes a positive electrode collector (sometimes referred to as "end face positive electrode collector 11" in this specification) arranged on one face in the stacking direction and a negative electrode collector (sometimes referred to as "end face negative electrode collector 12" in this specification) arranged on the other face. In addition, the electrode stack 50 includes a collector (sometimes referred to as "internal collector 20" in this specification). In addition, Figure 4B In the figure, layers other than the end face positive electrode collector 11, the end face negative electrode collector 12, and the internal current collector 20 vary depending on the target battery and are not specifically shown in the figure.

[0046] The number of internal current collectors 20 is not particularly limited and can be appropriately set according to the purpose. Figure 3 , Figure 4A , Figure 4BIn the embodiment, a plurality of internal current collectors 20 (a total of 8) are arranged inside the electrode stack 50. The internal current collector 20 may be a positive electrode current collector or a negative electrode current collector. In addition, the internal current collector 20 may be a current collector of the same type or a current collector of a different type. However, the internal current collector 20 has the function of providing battery information to the outside as described later, so it may be composed entirely of the same type of current collector (preferably a positive electrode current collector). In addition, the electrode stack 50 may also have a common current collector other than the internal current collector 20 inside it.

[0047] The internal current collector 20 is different from other current collectors in that it has a connection portion 22 drawn out from the side surface of the electrode stack 50 . Figure 5A A top view of the internal current collector 20 is shown, Figure 5B A plurality of internal current collectors 20 are shown for explaining the differences in the positions of the connection portions 22 .

[0048] like Figure 5A As shown, the internal current collector 20 includes a main body 21 and a connecting portion 22. The main body 21 is a portion that is stacked inside the electrode stack 50 and functions as a current collector. Therefore, a positive electrode layer or a negative electrode layer is stacked in the main body 21. The main body 21 has a rectangular shape. In contrast, the connecting portion 22 is a portion for providing battery information (voltage, current, etc.) to the outside, and has a long and thin strip shape. The connecting portion 22 is used, for example, as a voltage monitoring line. As shown in FIG. Figure 3 , Figure 4A , Figure 4B As shown, the connecting portion 22 has a form of being led out from the side surface 50a of the electrode stack 50, and the led-out connecting portion 22 is bent in the stacking direction. Moreover, the end of the connecting portion 22 is further bent and arranged on the same surface as the end face positive electrode collector 11. In this way, the connecting portion 22 is characterized in that it extends in the stacking direction on the side surface 50a of the electrode stack 50 and is arranged on the same surface as the end face positive electrode collector 11.

[0049] In this way, the connection portion 22 is characterized in that it extends in the stacking direction on the side of the electrode stack 50 and is arranged on the same surface as the end face positive electrode collector 11. In previous batteries, the connection portion that functions as a voltage monitoring line is led out to the side direction. In contrast, in the battery 100, the connection portion 22 has a portion extending in the stacking direction on the side of the electrode stack 50, thereby reducing the area occupied by the connection portion 22 in the battery 100 as a whole. In addition, in Japanese Patent Application Laid-Open No. 2019-53845, an exterior component having a through hole for leading the voltage monitoring terminal to the outside is required, and the structure of the exterior component is limited. In contrast, in the battery 100, the connection portion 22 is arranged on the same surface as the end face positive electrode collector 11, thereby improving the structural efficiency with a simple structure.

[0050] Here, in the connection portion 22 , the portion drawn out from the side surface of the electrode stack 50 and extending in the stacking direction of the side surface 50 a is referred to as the extension portion 23 , and the portion arranged on the same surface as the end surface positive electrode current collector 11 is referred to as the end portion 24 .

[0051] like Figure 5B As shown, the position of the connection portion 22 in the internal current collector 20 is not particularly limited and may be as shown in FIG. Figure 3 , Figure 4A , Figure 4B As shown in FIG. 1 , the connecting portions 22 drawn from the plurality of internal current collectors 20 are arranged at positions that do not overlap each other when viewed in the stacking direction. This can suppress contact between the connecting portions 22 and simplify the battery structure. Figure 5B As shown, the length of the connecting portion 22 can be arbitrarily set to match the position of the end portion 24 .

[0052] Here, "the connection portion 22 is arranged on the same surface as the end face positive electrode current collector 11" is further explained. Figure 3 , Figure 4A , Figure 4B As shown, the end 24 of the connection portion 22 is arranged on the end face positive electrode collector 11 via the end face insulating layer 30. Therefore, although it cannot be strictly said that the end 24 of the connection portion 22 is arranged on the same surface as the end face positive electrode collector 11, since the end face insulating layer 30 is a very thin layer, it can be said that these are arranged on the same surface from the perspective of use. Therefore, "the connection portion 22 is arranged on the same surface as the end face positive electrode collector 11" does not strictly mean that the end 24 of the connection portion 22 is arranged on the same surface as the end face positive electrode collector 11, but from the perspective of use, it means that the end 24 of the connection portion 22 is arranged on the same surface as the end face positive electrode collector 11.

[0053] In addition, in the electrode stack 50, the connection portion 22 is arranged on the same surface as the end face positive electrode collector 11, but it is not limited to this. The connection portion 22 may also be arranged on the same surface as the end face negative electrode collector 12. In addition, a part of the plurality of connection portions 22 may be arranged on the same surface as the end face positive electrode collector 11, and the remaining part may be arranged on the same surface as the end face negative electrode collector 12. Therefore, the connection portion 22 may extend in the stacking direction on the side surface 50a of the electrode stack 50 and be arranged on the same surface as at least one of the end face positive electrode collector 11 and the end face negative electrode collector 12.

[0054] (End surface insulation layer 30)

[0055] The electrode stack 50 has an end face insulating layer 30. The end face insulating layer 30 is arranged on a portion of the end face positive electrode collector 11. Moreover, the connection portion 22 (end portion 24) is arranged on the end face positive electrode collector 11 via the end face insulating layer 30, and the end portion 24 and the end face positive electrode collector 11 are insulated by the end face insulating layer 30. In this way, the end face insulating layer 30 is arranged between the end portion 24 and the end face positive electrode collector 11, and has the function of insulating these.

[0056] The material of the end face insulating layer 30 is not particularly limited, and examples thereof include polyimide, polypropylene, polyethylene, polyvinyl chloride, polytetrafluoroethylene, and the like. The thickness of the end face insulating layer 30 is not particularly limited, and for example, it is 5 μm to 300 μm. The configuration method of the end face insulating layer 30 is not particularly limited, and for example, a resin tape may be attached to the end face positive electrode collector 11. In addition, a resin sheet may be disposed between the end face positive electrode collector 11 and the end portion 24 of the connecting portion 22. Alternatively, a resin material may be coated on the end face positive electrode collector 11.

[0057] In addition, the end face insulating layer 30 may be disposed at the end portion 24. Even if the end face insulating layer 30 is disposed at the end portion 24, the end portion 24 and the end face positive electrode collector 11 can be insulated by the end face insulating layer 30. Therefore, the end face insulating layer 30 may be disposed between the end portion 24 and the end face positive electrode collector 11.

[0058] (Side insulation layer 40)

[0059] The electrode stack 50 has a side insulating layer 40. The side insulating layer 40 is arranged on the side 50a of the electrode stack 50. Moreover, the side insulating layer 40 is used to insulate the connecting portion 22 (extension portion 23) and the side 50a of the electrode stack 50. In this way, the side insulating layer 40 is arranged on the side 50a, and has the function of insulating the extension portion 23 and the side 50a. Therefore, the side insulating layer 40 can be arranged on at least a part of the side 50a. The side insulating layer 40 can also be arranged on the entire side 50a.

[0060] The material of the side insulating layer 40 is not particularly limited, and examples thereof include polyimide, polypropylene, polyethylene, polyvinyl chloride, polytetrafluoroethylene, and the like. The thickness of the side insulating layer 40 is not particularly limited, and is, for example, 5 μm to 300 μm. The configuration method of the side insulating layer 40 is not particularly limited, and for example, a resin tape may be attached to the side 50a of the electrode stack 50. In addition, a resin sheet may be disposed between the side 50a of the electrode stack 50 and the extension 23 of the connection portion 22. Alternatively, a resin material may be applied to the side 50a of the electrode stack 50.

[0061] In addition, the side insulating layer 40 may be disposed on the extension portion 23. Even if the side insulating layer 40 is disposed on the extension portion 23, the extension portion 23 and the side surface 50a of the electrode stack 50 can be insulated by the side insulating layer 40. Therefore, the side insulating layer 40 may be disposed on at least one of the extension portion 23 and the side surface 50a of the electrode stack 50.

[0062] (Stacking Method of Electrode Stack 50)

[0063] As described above, the electrode stack 50 is a stack including a current collector, a positive electrode layer, an electrolyte layer, and a negative electrode layer, and end current collectors 11 and 12 are stacked on both sides of the electrode stack 50 in the stacking direction, and a plurality of internal current collectors 20 are provided therein. Other structures are not particularly limited. Figure 6 A cross-sectional view of an electrode stack 50 is shown as an example. Figure 6 The electrode stack 50 shown is an electrode stack for a bipolar lithium ion secondary battery.

[0064] like Figure 6 As shown, the electrode stack 50 is formed by stacking a plurality of electrode bodies 56. In the electrode stack 50, the number of electrode bodies 56 is not particularly limited and can be appropriately set according to the purpose.

[0065] The electrode body 56 includes a positive electrode collector 51, a negative electrode collector 52, a positive electrode layer 53, a negative electrode layer 54, and an electrolyte layer 55. The electrode body 56 is formed by overlapping the negative electrode layer 54 disposed on the upper surface of the negative electrode collector 52 and the positive electrode layer 53 disposed on the lower surface of the positive electrode collector 51 with the electrolyte layer 55 interposed therebetween. The electrode stack 50 is formed by stacking a plurality of electrode bodies 56 in a manner connected in series.

[0066] Here, the positive electrode collector 51 disposed on one side of the stacking direction of the electrode stack 50 corresponds to the end face positive electrode collector 11, and the negative electrode collector 52 disposed on the other side of the stacking direction corresponds to the end face negative electrode collector 12. In addition, the positive electrode collector 51 or the negative electrode collector 52 contained in the electrode stack 50 corresponds to the internal collector 20. Figure 6 In the embodiment of the present invention, the positive electrode current collector 51 included in the electrode stack 50 is referred to as the internal current collector 20 .

[0067] <Exterior body 90>

[0068] like Figure 1 , Figure 2A , Figure 2B As shown, the outer casing 90 is made of metal and has a rectangular shape when viewed in the stacking direction. The outer casing 90 is a box-shaped member having a space inside which can accommodate the electrode stack 50.

[0069] (Basic Structure of Exterior Body 90)

[0070] First, the basic structure of the outer casing 90 will be described. The outer casing 90 includes a positive electrode outer casing 91 and a negative electrode outer casing 92. In addition, the outer casing 90 includes insulating resins 93 and 94.

[0071] The positive electrode outer casing 91 is made of metal and has a box-like shape with a rectangular bottom plate 91a and four side plates 91b on each side of the common bottom plate 91a. That is, the positive electrode outer casing 91 has a U-shaped cross-section. In addition, in the positive electrode outer casing 91, the surface facing the bottom plate 91a is open. The negative electrode outer casing 92 is made of metal and has a box-like shape with a rectangular bottom plate 92a and four side plates 92b on each side of the common bottom plate 92a. That is, the negative electrode outer casing 92 has a U-shaped cross-section. In addition, in the negative electrode outer casing 92, the surface facing the bottom plate 92a is open. Moreover, the positive electrode outer casing 91 and the negative electrode outer casing 92 are overlapped in a manner that the bottom plates face each other in the stacking direction and the side plates face each other in a direction orthogonal to the stacking direction. Thus, a space capable of accommodating the electrode stack 50 can be formed inside the exterior body 90 .

[0072] Here, the bottom plate 91a of the positive electrode outer casing 91 is formed to have a larger area than the bottom plate 92a of the negative electrode outer casing 92. Therefore, when the electrode stack 50 is housed in the outer casing 90, the side plate 92b of the negative electrode outer casing 92 is arranged inside the side plate 91b of the positive electrode outer casing 91.

[0073] The metal constituting the positive electrode outer package 91 and the negative electrode outer package 92 is not particularly limited, and examples thereof include aluminum, aluminum alloy, stainless steel, copper, copper alloy, and nickel steel, etc. The thickness of the positive electrode outer package 91 and the negative electrode outer package 92 is not particularly limited, and for example, is 0.05 mm or more and 2.0 mm or less.

[0074] The resin 93 is disposed between the side surface of the electrode stack 50 and the side plate 92b of the positive electrode outer package 91. Thus, the side surface of the electrode stack 50 and the side plate 92b of the positive electrode outer package 91 are insulated and can be fixed. The resin 94 is disposed between the side plate 91b of the positive electrode outer package 91 and the side plate 92b of the negative electrode outer package 92. Thus, the side plate 91b of the positive electrode outer package 91 and the side plate 92b of the negative electrode outer package 92 are insulated and can be fixed.

[0075] For example, Japanese Patent Application No. 2023-006850 describes the basic structure of such an outer layer body 90 .

[0076] (Characteristic Structure of Exterior Body 90)

[0077] Next, characteristic parts of the outer casing 90 are described. The outer casing 90 includes a positive electrode terminal 61 disposed on one surface in the stacking direction, a negative electrode terminal 62 disposed on the other surface in the stacking direction, and a plurality of connection terminals 70 disposed on the same surface as the positive electrode terminal 61 .

[0078] The positive terminal 61 is the bottom plate 91a of the positive electrode outer casing 91 and is the portion exposed to the outside. Typically, in the bottom plate 91a of the positive electrode outer casing 91, an insulating layer may be arranged on the inner surface except for the portion in contact with the end face positive electrode collector 11, and an insulating layer 95 may be arranged on the outer surface except for the portion connected to the outside (see Figure 1 ,exist Figure 2A , Figure 2B (not shown in the figure). In this case, the positive terminal 61 is a portion of the bottom plate 91a of the positive electrode outer casing 91 that is not provided with an insulating layer and is exposed to the outside. The same is true for the negative terminal 62. The negative terminal 62 is the bottom plate 92a of the negative electrode outer casing 92 and is a portion exposed to the outside. Typically, in the bottom plate 92a of the negative electrode outer casing 92, an insulating layer may be provided on the inner surface except for the portion in contact with the end face negative electrode collector 12, and an insulating layer may be provided on the outer surface except for the portion connected to the outside. In this case, the negative terminal 62 is a portion of the bottom plate 92a of the negative electrode outer casing 92 that is not provided with an insulating layer and is exposed to the outside.

[0079] In addition, both surfaces of the side plate 91b of the positive electrode outer casing 91 and the side plate 92b of the negative electrode outer casing 92 may be covered with an insulating layer. Thus, the inner surface of the side plate of the outer casing 90 (the inner surface of the side plate 92b of the negative electrode outer casing 92) and the electrode stack 50 can be insulated. In addition, the outer surface of the side plate of the outer casing 90 (the outer surface of the side plate 91b of the positive electrode outer casing 91) and external components can be insulated.

[0080] Here, the positive terminal 61 is in direct contact with and electrically connected to the positive electrode collector 11 at the end of the electrode stack 50 inside the outer casing 90. The negative terminal 62 is in direct contact with and electrically connected to the negative electrode collector 12 at the end of the electrode stack 50 inside the outer casing 90. Therefore, both end surfaces of the outer casing 90 in the stacking direction function as terminals. In this way, the positive terminal 61 and the negative terminal 62 are electrically connected to the positive electrode collector 11 and the negative electrode collector 12 at the end of the electrode stack 50 inside the outer casing 90, so that airtightness and gas barrier properties are guaranteed.

[0081] In addition, from the perspective of improving structural efficiency, the positive terminal 61 and the end face positive electrode collector 11 are directly in contact and electrically connected inside the outer casing 90, but the present invention is not limited to this mode. The positive terminal 61 and the end face positive electrode collector 11 may also be indirectly electrically connected inside the outer casing 90 via a conductive component or the like. Similarly, from the perspective of improving structural efficiency, the negative terminal 62 and the end face negative electrode collector 12 are directly in contact and electrically connected inside the outer casing 90, but the present invention is not limited to this mode. The negative terminal 62 and the end face negative electrode collector 12 may also be indirectly electrically connected inside the outer casing 90 via a conductive component or the like.

[0082] The connection terminal 70 is electrically connected to the connection portion 22 of the electrode stack 50, and has the function of providing information of the electrode stack 50 to the outside. The connection terminal 70 is arranged on the bottom plate 91a of the positive electrode outer casing 91. That is, the connection terminal 70 is arranged on the same surface as the positive electrode terminal 61. The connection terminal 70 is directly in contact with the end portion 24 of the connection portion 22 inside the outer casing 90 and is electrically connected. The number of the connection terminals 70 corresponds to the number of the connection portions 22, and each connection terminal 70 is connected to each connection portion 22.

[0083] The specific structure of the connection terminal 70 will be described. Figure 7 FIG. 8 is a partial cross-sectional view of the connection terminal 70. Figure 7 As shown, the connection terminal 70 has a through hole 71 that penetrates the end surface of the outer casing 90 (the bottom plate 91a of the positive electrode outer casing 91) in the stacking direction, a metal portion 72 arranged in the through hole 71, and an insulating layer 73 arranged between the through hole 71 and the metal portion 72.

[0084] The through hole 71 penetrates the end surface of the outer casing 90 (the bottom plate 91a of the positive electrode outer casing 91) in the stacking direction. The size of the through hole 71 is not particularly limited and can be appropriately set according to the purpose. For example, the size of the through hole 71 can be 0.05 mm to 1.0 mm. The shape of the through hole 71 is not particularly limited, and is typically circular.

[0085] The metal portion 72 is a portion that is in direct contact with and electrically connected to the end portion 24 of the connection portion 22 inside the outer casing 90. The metal portion 72 is connected to the end portion 24 of the connection portion 22 inside the outer casing 90, thereby ensuring airtightness and gas barrier properties. The metal constituting the metal portion 72 is not particularly limited. For example, copper, gold, silver, nickel, chromium, etc. can be cited. Although the metal portion 72 can also be arranged only in the through hole 71, from the perspective of improving connectivity, it can also be arranged in addition to being arranged inside the through hole 71, and also arranged on the inner surface peripheral portion and the outer surface peripheral portion of the outer casing 90 (the bottom plate 91a of the positive electrode outer casing 91) that is continuous from the through hole 71.

[0086] In addition, from the perspective of improving structural efficiency, the metal portion 72 and the end portion 24 of the connecting portion 22 are directly in contact and electrically connected inside the outer casing 90, but the present invention is not limited to this method. The metal portion 72 and the end portion 24 of the connecting portion 22 may also be indirectly electrically connected inside the outer casing 90 via a conductive member or the like.

[0087] The insulating layer 73 has the function of insulating the metal part 72 and the outer casing 90 (positive electrode outer casing 91). The insulating layer 73 is arranged between the outer casing 90 (positive electrode outer casing 91) and the metal part 72. In the case where the metal part 72 is arranged only inside the through hole 71, the insulating layer 73 can be provided only on the inner side of the through hole 71. In the case where the metal part 72 is arranged inside the through hole 71 and on the inner surface peripheral part and the outer surface peripheral part of the outer casing 90 (bottom plate 91a of the positive electrode outer casing 91) continuous from the through hole 71, the insulating layer 73 can be arranged on the inner side of the through hole 71 and on the inner side peripheral part and the outer side peripheral part of the outer casing 90 continuous from the through hole 71. Typically, as described above, in the bottom plate 91a of the positive electrode outer casing 91, the insulating layer 95 is arranged on the portion other than the positive electrode terminal 61. Therefore, typically, the insulating layer 73 constitutes a part of the insulating layer 95 , and is disposed inside the through hole 71 and inside and outside peripheral portions of the exterior body 90 that are continuous from the through hole 71 .

[0088] The material of the insulating layer 73 is not particularly limited, and examples thereof include polyimide, polypropylene, polyethylene, polyvinyl chloride, and polytetrafluoroethylene.

[0089] The method of providing the connection terminal 70 to the exterior body 90 is not particularly limited, and the following method can be cited as an example. Figure 8 An example of a method of providing the connection terminal 70 to the exterior body 90 is shown. Figure 8 : is a cross-sectional view of a positive electrode outer package 91. First, a through hole 71 is provided at a predetermined position of a bottom plate 91a of the positive electrode outer package 91. Next, a portion of the bottom plate 91a that will become a positive electrode terminal 61 is covered with a predetermined mask member M, and an insulating layer is provided for the other portion. Furthermore, a metal portion 72 is provided for the through hole 71 provided with the insulating layer 73. A method of providing the metal portion 72 may include, for example, plating.

[0090] (Effect)

[0091] In the collector plate configuration structure described in Japanese Patent Application Laid-Open No. 2019-53845, a through hole is provided in the exterior member, from which electrodes and voltage monitoring terminals are led out to the outside.

[0092] In contrast, in the battery 100, inside the outer body 90, the end face positive electrode collector 11 and the positive terminal 61 are electrically connected, the end face negative electrode collector 12 and the negative terminal 62 are electrically connected, and the connecting portion 22 and the connecting terminal 70 are electrically connected. Therefore, the battery 100 guarantees air tightness and gas barrier properties, and the air tightness and gas barrier properties are improved compared with the prior art. In addition, in the battery 100, the end face electrode terminal and the connecting terminal are arranged on the same surface. Therefore, as in Japanese Patent Laid-Open No. 2019-53845, the structural efficiency can be improved compared with the prior art.

[0093] As described above, the battery of the present disclosure has been described using one embodiment. According to the battery of the present disclosure, airtightness and gas barrier properties can be improved, and structural efficiency can be improved.

Claims

1. A battery comprising an electrode stack inside an outer casing, wherein: An end face positive electrode current collector is arranged on one surface of the electrode stack in the stacking direction. An end surface negative electrode collector is arranged on the other side of the electrode stack in the stacking direction. An internal current collector is stacked inside the electrode stack. The internal current collector has a connection portion extending from a side surface of the electrode stack. A positive electrode terminal is arranged on one surface of the outer casing in the stacking direction. A negative electrode terminal is arranged on the other side of the stacking direction of the outer casing. A connection terminal is arranged on the same surface as at least one of the positive electrode terminal and the negative electrode terminal. Inside the outer casing, the end surface positive electrode collector and the positive electrode terminal are electrically connected, the end surface negative electrode collector and the negative electrode terminal are electrically connected, and the connecting portion and the connecting terminal are electrically connected.

2. The battery according to claim 1, wherein The outer casing is made of metal, The connection terminal includes a through hole penetrating through an end surface of the exterior body in a stacking direction, a metal portion disposed in the through hole, and an insulating layer disposed between the through hole and the metal portion.

3. The battery according to claim 2, wherein The insulating layer is disposed on the inner side of the through hole and the inner peripheral portion and the outer peripheral portion of the outer casing which are continuous from the through hole.

4. The battery according to any one of claims 1 to 3, wherein Inside the outer casing, the end face positive electrode collector and the positive electrode terminal are in direct contact, the end face negative electrode collector and the negative electrode terminal are in direct contact, and the connecting portion and the connecting terminal are in direct contact.

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