Battery

Abstract

To provide a battery capable of improving structural efficiency with a simple structure.SOLUTION: A battery includes an electrode laminate. End face current collectors are disposed on both surfaces of the direction of lamination of the electrode laminate. Internal current collectors are laminated inside the electrode laminate. Each internal current collector has a connection part extending from the side surface of each electrode laminate. The connection part extends in the direction of lamination along the side surface of the electrode laminate and is arranged on the same surface as at least one end-surface current collector.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] This application relates to a battery.

Background Art

[0002] Patent Document 1 discloses a current collector plate arrangement structure of a bipolar battery in which a voltage monitoring terminal (current collector plate) extends along the stacking direction outside the outer surface of the side wall sealing material or between the battery cell stack and the side wall sealing material, and an end portion thereof is disposed on the upper surface of the upper wall sealing material. According to Patent Document 1, it is described that by disposing the voltage monitoring terminal on the upper surface of the upper wall sealing material, the exclusive area of the voltage monitoring terminal on the cell side surface can be suppressed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the current collector plate arrangement structure of Patent Document 1, an exterior material having a through hole for drawing out the voltage monitoring terminal to the outside is essential, and there are limitations in the structure of the exterior material.

[0005] Therefore, in view of the above circumstances, a main object of the present disclosure is to provide a battery that can improve structural efficiency with a simple structure.

Means for Solving the Problems

[0006] The present disclosure provides at least the following aspects.

[0007] The first aspect is a battery including an electrode laminate, wherein end face current collectors are disposed on both surfaces of the electrode laminate in the stacking direction, an internal current collector is stacked inside the electrode laminate, the internal current collector has a connection portion drawn out from a side surface of the electrode laminate, the connection portion extends in the stacking direction along the side surface of the electrode laminate, and is disposed on the same surface as at least one of the end face current collectors.

[0008] The second aspect is the battery according to the first aspect, wherein a plurality of internal current collectors are stacked inside the electrode laminate, and each connection portion drawn out from the plurality of internal current collectors is disposed at a position where they do not overlap each other when viewed in the stacking direction.

[0009] The third aspect is the battery according to the first or second aspect, wherein the connection portion is disposed on the end face current collector via an end face insulating layer, and the connection portion and the end face current collector are insulated by the end face insulating layer.

[0010] The fourth aspect is the battery according to any one of the first to third aspects, wherein when a portion of the connection portion that extends in the stacking direction along the side surface of the electrode laminate is defined as an extension portion, a side surface insulating layer is disposed on at least one of the extension portion and the side surface of the electrode laminate, and the connection portion and the side surface of the electrode laminate are insulated by the side surface insulating layer.

Advantages of the Invention

[0011] According to the battery of the present disclosure, the structural efficiency can be improved with a simple structure.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0013] The battery of the present disclosure will be described using a battery 100 which is one embodiment.

[0014] A plan view of the battery 100 is shown in FIG. 1. A front view observed from the direction of II in FIG. 1 is shown in FIG. 2. A side view of the battery 100 observed from the direction of III in FIG. 1 is shown in FIG. 3.

[0015] The battery 100 includes an electrode laminate 50.

[0016] <Electrode laminate 50> The electrode laminate 50 has a rectangular shape when viewed in the stacking direction, and is a laminate including a current collector (a positive electrode current collector and a negative electrode current collector), a positive electrode layer, a negative electrode layer, and an electrolyte layer. In the electrode laminate 50, the number of stacked layers of each layer is not particularly limited and may be appropriately set according to the purpose. The stacking form of the electrode laminate 50 is not particularly limited, and it may be a monopolar type or a bipolar type. The electrode laminate 50 may be a liquid-based battery or a solid battery. The electrode laminate 50 may be a lithium ion battery, a sodium ion battery, a nickel metal hydride battery, or the like. The electrode laminate 50 may be a primary battery or a secondary battery.

[0017] (Materials of the electrode laminate 50) Typical examples of the materials of each layer constituting the electrode laminate 50 will be shown and described. However, the materials of each layer constituting the electrode laminate 50 are not limited thereto.

[0018] The current collector is a sheet-shaped conductive member. Examples of the current collector include metal foils such as stainless steel, iron, copper, aluminum, titanium, nickel, etc. The metal foil may be made of an alloy containing two or more of these metals. Further, the metal foil may be subjected to surface treatment such as predetermined plating. The current collector may be composed of a plurality of metal foils. In this case, the metal foils may be joined with an adhesive or the like, or may be joined by pressing or the like. The shape of the current collector may be rectangular. The thickness of the current collector is not particularly limited, but is, for example, 1 μm to 1 mm.

[0019] The positive electrode layer contains at least a positive electrode active material. The positive electrode active material is not particularly limited and may be appropriately selected from any materials according to the intended battery performance. For example, composite oxides, metal lithium, sulfur, etc. are included. The composition of the composite oxide includes, for example, at least one of iron, manganese, titanium, nickel, cobalt, and aluminum, and lithium. Examples of the composite oxide include olivine-type lithium iron phosphate (LiFePO 4 ) and the like.

[0020] The positive electrode layer may optionally contain a conductive assistant. The conductive assistant is not particularly limited and may be appropriately selected from any materials according to the intended battery performance. For example, carbon materials such as acetylene black, carbon black, and graphite are included.

[0021] The positive electrode layer may optionally contain a binder. The binder is not particularly limited and may be appropriately selected from any materials according to the intended battery performance. For example, rubber-based resins, fluoride-based resins, etc. are included.

[0022] The positive electrode layer may optionally contain a solid electrolyte. The solid electrolyte is not particularly limited and may be appropriately selected from any materials according to the intended battery performance. For example, oxide solid electrolytes, sulfide solid electrolytes, etc. are included.

[0023] The positive electrode layer may be rectangular. 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 target battery performance. Note that the positive electrode layer may contain materials other than those described above.

[0024] The negative electrode layer contains a negative electrode active material. The negative electrode active material is not particularly limited and may be appropriately selected from any materials according to the target battery performance. Examples include carbon materials such as graphite, artificial graphite, hard carbon, and soft carbon, metal compounds, elements capable of alloying with lithium or their compounds, etc. Examples of elements capable of alloying with lithium include silicon and tin.

[0025] The negative electrode layer may optionally contain a conductive assistant. The conductive assistant is not particularly limited and may be appropriately selected from any materials according to the target battery performance. For example, it may be appropriately selected from the conductive assistants applicable to the positive electrode layer.

[0026] The negative electrode layer may optionally contain a binder. The binder is not particularly limited and may be appropriately selected from any materials according to the target battery performance. For example, it may be appropriately selected from the binders applicable to the positive electrode layer.

[0027] The negative electrode layer may optionally contain a solid electrolyte. The solid electrolyte is not particularly limited and may be appropriately selected from any materials according to the target battery performance. For example, it may be appropriately selected from the solid electrolytes applicable to the positive electrode layer.

[0028] The negative electrode layer may be rectangular. The thickness of the negative electrode layer is not particularly limited and is, for example, in the range of 1 μm to 1 mm. From the perspective of improving the output, the area of the negative electrode layer may be larger than that of the positive electrode layer. The content of each material in the negative electrode layer is not particularly limited and may be appropriately set according to the target battery performance. Note that the negative electrode layer may contain materials other than those described above.

[0029] When the electrolyte layer is a liquid electrolyte layer, the electrolyte layer includes a separator and an electrolyte solution. The separator is mainly a porous sheet made of polyolefin. The electrolyte solution is a non-aqueous solvent in which a supporting salt is dissolved. Examples of the non-aqueous solvent include carbonates, ethers, esters, etc. The supporting salt is, for example, LiPF 6 , LiBF 4 , lithium bis(fluorosulfonyl)imide (LiFSI), lithium bis(trifluoromethane)sulfonimide (LiTFSI), etc.

[0030] When the electrolyte layer is a solid electrolyte layer, the electrolyte layer includes a solid electrolyte. Further, the solid electrolyte layer may include a binder. The solid electrolyte and the binder may be appropriately selected from the above-mentioned solid electrolytes and binders.

[0031] The electrolyte layer may be rectangular. The thickness of the electrolyte layer is not particularly limited and is, for example, in the range of 1 μm to 1 mm.

[0032] (End face current collectors 11, 12, internal current collector 20) As described in FIGS. 1 to 3, current collectors (sometimes referred to as "end face current collectors 11, 12" in this specification) are arranged on both sides of the electrode laminate 50 in the lamination direction. Further, the electrode laminate 50 has a current collector (sometimes referred to as "internal current collector 20" in this specification) laminated inside.

[0033] The end face current collectors 11 and 12 are respectively arranged on both end faces of the electrode laminate 50 in the lamination direction. The end face current collectors 11 and 12 may be a positive electrode current collector or a negative electrode current collector. Further, the end face current collectors 11 and 12 may be the same type of current collector or different types of current collectors. Typically, the end face current collectors 11 and 12 are different types of current collectors.

[0034] The internal current collector 20 is laminated inside the electrode laminate 50. The number of the internal current collectors 20 is not particularly limited and may be appropriately set according to the purpose. In FIGS. 1 to 3, a plurality of internal current collectors 20 (a total of eight) are arranged inside the electrode laminate 50. The internal current collector 20 may be a positive electrode current collector or a negative electrode current collector. Also, the internal current collectors 20 may be of the same type or different types. However, since the internal electrode 40 has a role of providing battery information to the outside as described later, it may be composed of all the same type of current collectors (preferably positive electrode current collectors). Further, the electrode laminate 50 may include a normal current collector other than the internal current collector 20 inside thereof.

[0035] One feature of the internal current collector 20 is that, unlike other current collectors, it includes a connection portion 22 drawn out from the side surface of the electrode laminate 50. FIG. 4(A) shows a plan view of the internal current collector 20, and FIG. 4(B) shows a plurality of internal current collectors 20 to explain the difference in the position of the connection portion 22.

[0036] As shown in FIG. 4(A), the internal current collector 20 includes a main body portion 21 and a connection portion 22. The main body portion 21 is a portion that is laminated inside the electrode laminate 50 and functions as a current collector. Therefore, a positive electrode layer or a negative electrode layer is laminated on the main body portion 21. The main body portion 21 has a rectangular shape. On the other hand, the connection portion 22 is a portion for providing battery information (information such as voltage and current) to the outside and has an elongated strip shape. The connection portion 22 is used, for example, as a voltage monitoring line. As shown in FIGS. 1 to 3, the connection portion 22 has a form drawn out from the side surface 50a of the electrode laminate 50, and the drawn-out connection portion 22 is bent in the lamination direction. Then, the connection portion 22 is further bent, and its end portion is arranged on the same surface as the end face current collector 11. Thus, the connection portion 22 is characterized in that it extends in the lamination direction along the side surface 50a of the electrode laminate 50 and is arranged on the same surface as the end face current collector 11.

[0037] In conventional batteries, the connection part that functions as a voltage monitoring line had a form in which it was drawn out in the side direction. In contrast, in battery 100, the connection part 22 has a portion (extension part 23 described later) that extends in the stacking direction along the side surface 50a of the electrode laminate 50, whereby the area occupied by the connection part 22 in the entire battery 100 can be reduced. Further, in Patent Document 1, an exterior material provided with a through-hole for drawing out the voltage monitoring terminal to the outside was essential, and there were limitations on the structure of the exterior material. In contrast, in battery 100, the connection part 22 (end part 24 described later) is arranged on the same surface as the end face current collector 11, whereby the structural efficiency can be improved with a simple structure.

[0038] Here, among the connection part 22, the portion drawn out from the side surface of the electrode laminate 50 and extending in the stacking direction along the side surface 50a is defined as the extension part 23, and the portion arranged on the same surface as the end face current collector 11 is defined as the end part 24.

[0039] As shown in FIG. 4(B), the position of the connection part 22 in the internal current collector 20 is not particularly limited, but as shown in FIGS. 1 and 2, each connection part 22 drawn out from a plurality of internal current collectors 20 may be arranged at positions where they do not overlap each other in the stacking direction view. Thereby, contact between the connection parts 22 can be suppressed and the battery structure can be simplified. Further, as shown in FIG. 4(B), the length of the connection part 22 may be arbitrarily set according to the position of the end part 24.

[0040] Here, the statement that "the connection part 22 is arranged on the same plane as the end face current collector 11" will be further explained. As shown in FIGS. 1 and 3, the end part 24 of the connection part 22 is arranged on the end face current collector 11 via the end face insulating layer 30. Therefore, strictly speaking, it cannot be said that the end part 24 of the connection part 22 is arranged on the same plane as the end face current collector 11. However, since the end face insulating layer 30 is a very thin layer, from the perspective of use, it can be said that they are arranged on the same plane. Therefore, the statement that "the connection part 22 is arranged on the same plane as the end face current collector 11" does not strictly mean that the end part 24 of the connection part 22 is arranged on the same plane as the end face current collector 11, but means that from the perspective of use, it is sufficient that the end part 24 of the connection part 22 is arranged on the same plane as the end face current collector 11.

[0041] Note that in the electrode laminate 50, the connection part 22 is arranged on the same plane as the end face current collector 11, but it is not limited thereto. The connection part 22 may be arranged on the same plane as the end face current collector 12. Also, some of the plurality of connection parts 22 may be arranged on the same plane as the end face current collector 11, and the rest may be arranged on the same plane as the end face current collector 12. Therefore, the connection part 22 may extend in the stacking direction along the side face 50a of the electrode laminate 50 and be arranged on the same plane as at least one of the end face current collectors 11 and 12.

[0042] (Stacking form of the electrode laminate 50) As described above, the electrode laminate 50 is a laminate including a current collector, a positive electrode layer, an electrolyte layer, and a negative electrode layer. The end face current collectors 11 and 12 are laminated on both sides in the stacking direction of the electrode laminate 50, and a plurality of internal current collectors 20 are provided inside. Other configurations are not particularly limited. FIG. 5 shows a cross-sectional view of an example of the electrode laminate 50. The electrode laminate 50 shown in FIG. 5 is an electrode laminate for a bipolar lithium ion secondary battery.

[0043] As shown in FIG. 5, the electrode laminate 50 is formed by laminating a plurality of electrode bodies 56. In the electrode laminate 50, the number of the electrode bodies 56 is not particularly limited and may be appropriately set according to the purpose.

[0044] The electrode body 56 includes a positive current collector 51, a negative current collector 52, a positive electrode layer 53, a negative electrode layer 54, and an electrolyte layer 55. The electrode body 56 is formed by laminating a negative electrode layer 54 disposed on the upper surface of the negative current collector 52 and a positive electrode layer 53 disposed on the lower surface of the positive current collector 51 with the electrolyte layer 55 interposed therebetween. And the electrode laminate 50 is formed by laminating a plurality of electrode bodies 56 so that they are connected in series.

[0045] Here, the positive current collector 51 disposed on one surface in the stacking direction of the electrode laminate 50 corresponds to the end face positive current collector 11, and the negative current collector 52 disposed on the other surface in the stacking direction corresponds to the end face negative current collector 12. Also, the positive current collector 51 or the negative current collector 52 included inside the electrode laminate 50 corresponds to the internal current collector 20. In FIG. 5, the positive current collector 51 included inside the electrode laminate 50 is used as the internal current collector 20.

[0046] (End face insulating layer 30) The electrode laminate 50 has an end face insulating layer 30. The end face insulating layer 30 is disposed on a part of the end face current collector 11. And the connection part 22 (end part 24) is disposed on the end face current collector 11 via the end face insulating layer 30, and the end part 24 and the end face current collector 11 are insulated by the end face insulating layer 30. Thus, the end face insulating layer 30 is disposed between the end part 24 and the end face current collector 11 and has the role of insulating them. Therefore, the end face insulating layer 30 may be disposed on at least a part of the end face current collector 20. The end face insulating layer 30 may be disposed on the entire end face current collector 20.

[0047] The material of the end face insulating layer 30 is not particularly limited, and examples thereof include polyimide, polypropylene, polyethylene, polyvinyl chloride, polytetrafluoroethylene, etc. The thickness of the end face insulating layer 30 is not particularly limited, and for example, it is 5 μm to 300 μm. The method of disposing the end face insulating layer 30 is not particularly limited, and for example, a resin tape may be attached to the end face positive current collector 11. Also, a resin sheet may be disposed between the end face positive current collector 11 and the end part 24 of the connection part 22. Alternatively, a resin material may be applied to the end face positive current collector 11.

[0048] Note that 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 current 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 current collector 11.

[0049] (Side insulating layer 40) The electrode laminate 50 has a side insulating layer 40. The side insulating layer 40 is disposed on the side surface 50a of the electrode laminate 50. And, the connection portion 22 (extension portion 23) and the side surface 50a of the electrode laminate 50 are insulated by the side insulating layer 40. Thus, the side insulating layer 40 is disposed on the side surface 50a and has a role of insulating the extension portion 23 and the side surface 50a. Therefore, the side insulating layer 40 may be disposed on at least a part of the side surface 50a. The side insulating layer 40 may be disposed on the entire side surface 50a.

[0050] The material of the side insulating layer 40 is not particularly limited, and examples thereof include polyimide, polypropylene, polyethylene, polyvinyl chloride, polytetrafluoroethylene, etc. The thickness of the side insulating layer 40 is not particularly limited, and is, for example, 5 μm to 300 μm. The method of disposing the side insulating layer 40 is not particularly limited, and for example, a resin tape may be attached to the side surface 50a of the electrode laminate 50. Also, a resin sheet may be disposed between the side surface 50a of the electrode laminate 50 and the extension portion 23 of the connection portion 22. Alternatively, a resin material may be applied to the side surface 50a of the electrode laminate 50.

[0051] Note that the side insulating layer 40 may be disposed at the extension portion 23. Even if the side insulating layer 40 is disposed at the extension portion 23, the extension portion 23 and the side surface 50a of the electrode laminate 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 laminate 50.

[0052] (Battery 100) The battery 100 may include an exterior body that houses the electrode laminate 50. Further, the battery 100 may have electrode terminals connected to the electrode laminate 50, and may also have connection terminals connected to each connection portion 22.

[0053] As described above, the battery of the present disclosure has been described using one embodiment. According to the battery of the present disclosure, an exterior material having a through-hole is not required, and since the connection portion is disposed on the same surface as the end face current collector, the structural efficiency can be improved with a simple structure.

Description of Reference Numerals

[0054] 11, 12 End face current collector 20 Internal current collector 21 Main body portion 22 Connection portion 23 Extended portion 24 End portion 30 End face insulating layer 40 Side face insulating layer 50 Electrode laminate 50a Side face 51 Positive electrode current collector 52 Negative electrode current collector 53 Positive electrode layer 54 Negative electrode layer 55 Electrolyte layer 56 Electrode body 100 Battery

Claims

1. A battery including an electrode stack, end surface current collectors are disposed on both sides of the electrode laminate in the lamination direction; an internal current collector is laminated inside the electrode laminate, the internal current collector has a connection portion drawn out from a side surface of the electrode stack, the connection portion extends in a stacking direction along a side surface of the electrode stack and is disposed on the same plane as at least one of the end surface current collectors. battery.

2. A plurality of the internal current collectors are stacked inside the electrode stack, The connection portions drawn out from the plurality of internal current collectors are arranged at positions not overlapping with each other when viewed in the stacking direction.

10. The battery of claim 1.

3. the connection portion is disposed on the end surface current collector via the end surface insulating layer, The connection portion and the end surface current collector are insulated by the end surface insulating layer. The battery according to claim 1 or 2.

4. When a portion of the connection portion that extends in the stacking direction along a side surface of the electrode stack is defined as an extension portion, a side insulating layer is disposed on at least one of the side surfaces of the extension portion and the electrode stack; the side insulating layer insulates the connection portion and the side of the electrode stack; The battery according to claim 1 or 2.

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