Current collector terminal

Abstract

To provide a current collector terminal capable of ensuring fusion between a current collector terminal and a laminate film even if the accuracy of the current collecting terminal is alleviated.SOLUTION: There is provided a current collector terminal 110 for generating a battery 100 by being wound and covered with a laminate film 130 together with an electrode laminate 120. The current collector terminal 110 includes a conductive body part 110a and a resin buffer part 110b, the resin buffer part 110b being disposed on at least a portion of a surface to be fused with the laminate film 130.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a current collecting terminal. [Background technology]

[0002] A battery generally includes an electrode laminate having a positive electrode current collector layer, a positive electrode active material layer, an electrolyte layer, a negative electrode active material layer, and a negative electrode current collector layer. The electrode laminate of the battery is sealed in an internal space surrounded by an exterior material such as a laminate film, and the following batteries are known.

[0003] For example, Patent Document 1 discloses a battery comprising an electrode assembly, a side member disposed on a side surface of the electrode assembly, and a laminate film covering the electrode assembly, wherein, when the battery is viewed from the side of the side member, the outer edge of the side member is located inside the outer edge of the electrode assembly, the laminate film is disposed so as to cover the surface constituting the outer edge of the side member and the surface constituting the outer edge of the electrode assembly, and a fused portion where the inner surfaces of the laminate film are fused together is disposed on the side member. The battery in Patent Document 1 is said to be able to suppress deterioration of sealing performance. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2023-163373 Summary of the Invention [Problem to be solved by the invention]

[0005] For example, when covering a current collecting terminal directly with a laminate film and fusing the laminate film to the current collecting terminal as in Patent Document 1, strict standards must be met for the accuracy of the squareness of the current collecting terminal, the plate thickness tolerance, etc.

[0006] Therefore, an object of the present disclosure is to provide a current collecting terminal that can ensure fusion bonding between the current collecting terminal and a laminate film even if the precision of the current collecting terminal is relaxed. [Means for solving the problem]

[0007] The present disclosure achieves the above object by the following means.

[0008] <Aspect 1> A current collecting terminal for forming a battery by being wrapped and covered with a laminate film together with an electrode stack, the current collecting terminal has a conductive main body portion and a resin buffer portion, The resin buffer portion is disposed on at least a part of the surface to be fused to the laminate film. Current collector terminal. <Aspect 2> 2. The current collecting terminal according to claim 1, wherein the resin buffer portion is composed of two portions arranged to sandwich the conductive main body portion in the stacking direction of the electrode stack. <Aspect 3> 3. The current collecting terminal according to aspect 1 or 2, wherein the resin buffer portion has a lower Young's modulus than the fusion layer of the laminate film. <Aspect 4> an electrode stack; the current collecting terminal according to any one of Aspects 1 to 3, which is connected to the current collecting foil of the electrode laminate; and a laminate film that seals the electrode stack by winding the electrode stack and the current collecting terminals together; A battery having The current collecting terminal is wound around the laminate film so that the laminate film covers the resin buffer portion, and the laminate film and the resin buffer portion are heat-sealed. battery. <Aspect 5> The battery according to aspect 4, wherein, when the battery is viewed from the side from the collector terminal side, the outer edge of the collector terminal is located inside the outer edge of the electrode laminate, and a convex fused portion is formed around the corner of the collector terminal where the fusion layers of the laminate film are fused to each other. [Effects of the Invention]

[0009] According to the current collecting terminal of the present disclosure, even if the precision of the current collecting terminal is relaxed, the fusion bonding between the current collecting terminal and the laminate film can be ensured. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram illustrating a battery sealed with a laminate film. [Figure 2] FIG. 2 is a schematic diagram for explaining a current collecting terminal of the present disclosure. [Figure 3] FIG. 3 is a schematic diagram illustrating the battery of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present disclosure will be described in detail. Note that the present disclosure is not limited to the following embodiments, and various modifications can be made within the scope of the gist of the present disclosure. In addition, in the description of the drawings, the same elements are given the same reference numerals, and duplicated descriptions will be omitted.

[0012] The battery of the present disclosure may be a liquid-based battery containing an electrolytic solution as an electrolyte layer, or may be a solid-state battery having a solid electrolyte layer as an electrolyte layer. In the context of the present disclosure, a "solid-state battery" refers to a battery that uses at least a solid electrolyte as an electrolyte, and therefore a solid-state battery may use a combination of a solid electrolyte and a liquid electrolyte as an electrolyte. The battery of the present disclosure may also be an all-solid-state battery, i.e., a battery that uses only a solid electrolyte as an electrolyte.

[0013] 《Current collector terminal》 The current collecting terminal of the present disclosure comprises: A current collecting terminal for forming a battery by being wrapped and covered with a laminate film together with an electrode stack, the current collecting terminal has a conductive main body portion and a resin buffer portion, The resin buffer portion is disposed on at least a part of the surface that is fused to the laminate film.

[0014] According to the current collecting terminal of the present disclosure, even if the precision of the current collecting terminal is relaxed, the fusion bonding between the current collecting terminal and the laminate film can be ensured.

[0015] Without being limited by theory, by providing a resin buffer portion in the conductive main body portion as in the collector terminal of the present disclosure and arranging the resin buffer portion on at least a portion of the surface that is fused to the laminate film, even if the precision of the collector terminal is not sufficiently high, the resin buffer portion deforms to fit the conductive main body portion and the laminate film when the collector terminal and the laminate film are fused together, thereby ensuring the fusion of the collector terminal and the laminate film.

[0016] Fig. 1 is a schematic diagram showing one embodiment of a battery including a current collector terminal of the present disclosure, but is not limited to this embodiment. Fig. 2 is a schematic diagram showing one embodiment of a current collector terminal of the present disclosure, but is not limited to this embodiment.

[0017] 1A shows a state before a battery is formed by winding an electrode laminate 120 and a current collecting terminal 110 with a laminate film 130. The electrode laminate 120 has a current collecting foil 140 on a side surface 120a of the electrode laminate 120. The current collecting terminal 110 is connected to the current collecting foil 140 arranged on the side surface 120a of the electrode laminate 120. In FIG. 1B, the battery 100 is covered by winding the electrode laminate 120 and the current collecting terminal 110 with the laminate film 130, and the electrode laminate 120 is sealed in a space formed by the laminate film 130.

[0018] FIG. 2 shows a cross-sectional view of the battery 100 shown in FIG. 1B taken along line AA, particularly illustrating the area surrounding the current collecting terminal 110. The current collecting terminal 110 is connected to the current collecting foil 140 disposed on the side surface 120a of the electrode laminate 120 and includes a conductive main body 110a and a resin buffer 110b. The resin buffer 110b is disposed on the surface that will be fused to the laminate film 130. The resin buffer 110b of the current collecting terminal 110 ensures adhesion between the current collecting terminal and the laminate film even if precision of the current collecting terminal is relaxed. The current collecting terminal 110 can be fabricated by attaching the resin buffer 110b to the conductive main body 110a, although this is not particularly limited. Even if the precision of the conductive main body 110a is insufficient, the attachment of the resin buffer 110b ensures adhesion between the current collecting terminal and the laminate film.

[0019] The current collecting terminal of the present disclosure comprises: The resin buffer portion may be made up of two portions arranged to sandwich the conductive main body portion in the stacking direction of the electrode stack.

[0020] In FIG. 2 , the electrode stack 120 of the battery 100 is sandwiched between laminate films 130 on both the top and bottom sides. The electrode active material layers and electrolyte layers included in the electrode stack 120 are stacked parallel to the surface of the laminate film 130. In FIG. 2 , the resin buffer 110b of the current collecting terminal 110 is composed of two parts arranged to sandwich the conductive main body 110a in the stacking direction of the electrode stack 120. That is, the resin buffer 110b, the conductive main body 110a, and the resin buffer 110b are stacked in this order in the stacking direction of the electrode stack 120 to form the current collecting terminal 110. By having the resin buffer 110b composed of two parts arranged to sandwich the conductive main body 110a, it is possible to improve the adhesion between the current collecting terminal and the laminate film compared to a current collecting terminal composed of a single part in which the resin buffer is arranged only on the top or bottom surface of the conductive main body in the stacking direction.

[0021] "battery" The battery of the present disclosure comprises: an electrode stack; a current collecting terminal of the present disclosure connected to the current collecting foil of the electrode stack; and A laminate film that seals the electrode stack by winding the electrode stack and the current collecting terminals. A battery having The current collecting terminal is wound so that the laminate film covers the resin buffer portion, and the laminate film and the resin buffer portion are heat-sealed.

[0022] According to the battery of the present disclosure, even if the precision of the current collecting terminals is relaxed, the fusion bonding between the current collecting terminals and the laminate film can be ensured.

[0023] The battery of the present disclosure will be described using the aforementioned Figures 1B and 2. In Figure 1B, the battery 100 has an electrode stack 120 and a current collecting terminal 110 sealed with a laminate film. As mentioned above, Figure 2 shows an AA cross-sectional view of the battery 100 in Figure 1B. In Figure 2, the current collecting terminal 110 is wrapped with a laminate film 130 covering the resin buffer portion 110b. The laminate film 130 and the resin buffer portion 110b are heat-sealed, and the electrode stack 120 is sealed in the space surrounded by the laminate film 130, thereby forming the battery 100. The current collecting terminal of the present disclosure ensures adhesion between the current collecting terminal and the laminate film even if the precision of the current collecting terminal is relaxed.

[0024] The battery of the present disclosure comprises: When the battery is viewed from the side from the collector terminal side, the outer edge of the collector terminal is located inside the outer edge of the electrode laminate, and a convex fused portion formed around the corner of the collector terminal where the fused layers of the laminate film are fused together may be formed.

[0025] FIG. 3 is a schematic diagram showing one embodiment of the battery of the present disclosure, but is not limited to this embodiment.

[0026] In Fig. 3, when the battery 100 is viewed from the side of the current collecting terminal 110, a convex fused portion 130a is formed around the corner of the current collecting terminal 110, where the fused layers of the laminate film 130 are fused together. When the fused layers of the laminate film 130 are fused together to form the convex fused portion 130a, the precision of the current collecting terminal must be controlled according to stricter standards. By providing a resin buffer, the precision of the current collecting terminal can be relaxed. For example, even if the precision of the conductive main body is insufficient, the fusion between the current collecting terminal and the laminate film can be ensured by attaching an appropriate resin buffer to the conductive main body to form the current collecting terminal.

[0027] <<Configurations of current collecting terminals and batteries>> The configurations of the current collecting terminals and the battery will be described below.

[0028] <Collector terminal> The current collecting terminal has a conductive main body and a resin buffer portion.

[0029] (Conductive main body) The conductive body may be electrically connected to a tab on the positive electrode current collector layer or the negative electrode current collector layer of the electrode laminate. The material of the conductive body is not particularly limited, but may be metal such as stainless steel (SUS).

[0030] (Resin buffer) The material for the resin buffer portion is not particularly limited, but examples thereof include polyethylene and urethane.

[0031] The Young's modulus of the resin buffer is not particularly limited, but is preferably lower than that of the fusion layer of the laminate film. If the Young's modulus of the resin buffer is lower than that of the fusion layer of the laminate film, for example, the resin buffer will deform more significantly during fusion, thereby ensuring fusion between the current collecting terminal and the laminate film even if the precision of the current collecting terminal is further relaxed. The Young's modulus of the resin buffer may be 0.01 times or more, 0.10 times or more, 0.20 times or more, 0.25 times or more, 0.3 times or more, 0.4 times or more, or 0.50 times or more, or 0.90 times or less, 0.80 times or less, 0.70 times or less, or 0.60 times or less, relative to the Young's modulus of the fusion layer of the laminate film. The Young's modulus can be determined in accordance with JIS K7161-1 (2014).

[0032] <Electrode laminate> The electrode stack is not particularly limited, but may have a positive electrode current collector layer, a positive electrode active material layer, an electrolyte layer, a negative electrode active material layer, and a negative electrode current collector layer in this order.

[0033] <Positive electrode current collector layer> Examples of materials used for the positive electrode current collector layer include, but are not limited to, Cu, Ni, Cr, Au, Pt, Ag, Al, Fe, Ti, Zn, Co, and stainless steel. The positive electrode current collector layer may be in the form of, for example, a foil, a plate, or a mesh. The positive electrode current collector layer may have a positive electrode tab for connection to a positive electrode current collector terminal.

[0034] <Cathode active material layer> The positive electrode active material layer contains at least a positive electrode active material, and may further contain, as desired, a solid electrolyte, a conductive additive, a binder, and the like.

[0035] (Cathode active material) Positive electrode active materials include, for example, lithium cobalt oxide (LiCoO2), lithium manganese oxide (LiMn2O4), and nickel-cobalt-manganese lithium oxide (NCM:LiCO 1 / 3 Ni 1 / 3 Mn 1 / 3O2), but is not limited to these. The positive electrode active material may be in the form of particles, for example.

[0036] (solid electrolyte) The material of the solid electrolyte is not particularly limited, but may be a sulfide solid electrolyte, an oxide solid electrolyte, a polymer electrolyte, or the like. Examples of sulfide solid electrolytes include Li2S-P2S5-based (Li7P3S 11 Examples of oxide solid electrolytes include, but are not limited to, Li7La3Zr2O 12 , Li 7-x La3Zr 1-x Nb x O 12 Examples of the polymer electrolyte include, but are not limited to, polyethylene oxide (PEO).

[0037] (Conductive additive) The conductive additive may be, for example, vapor grown carbon fiber (VGCF), acetylene black (AB), ketjen black (KB), or the like, but is not limited thereto.

[0038] (binder) The binder may be, for example, but not limited to, materials such as polyvinylidene fluoride (PVdF), styrene butadiene rubber (SBR), and the like.

[0039] <Electrolyte layer - solid electrolyte layer> The battery of the present disclosure can be a solid-state battery, i.e., have a solid electrolyte layer as the electrolyte layer. The solid electrolyte layer contains at least an electrolyte, and may contain a conductive additive, a binder, and the like as necessary. For details about the solid electrolyte, the conductive additive, and the binder, please refer to the description of "(Positive Electrode Active Material Layer)" above.

[0040] <Electrolyte layer-electrolyte> The battery of the present disclosure can be a liquid battery, i.e., have an electrolyte solution as the electrolyte layer, particularly an electrolyte solution held in a separator layer.

[0041] (electrolyte) The electrolyte preferably contains, but is not limited to, a supporting salt and a solvent. Examples of supporting salts include, but are not limited to, LiPF6, LiCF3SO2, etc. Examples of solvents used in the electrolyte include, but are not limited to, ethylene carbonate (EC), diethyl carbonate (DEC), etc.

[0042] (separator) The separator is not particularly limited, but may be a polyolefin-based, polyamide-based, polyimide-based nonwoven fabric, or the like.

[0043] <Negative electrode active material layer> The negative electrode active material layer contains at least a negative electrode active material, and may further contain, optionally, a conductive additive, a binder, a solid electrolyte, and the like.

[0044] (Negative electrode active material) The material of the negative electrode active material is not particularly limited, and may be metallic lithium or a material capable of absorbing and releasing metal ions such as lithium ions. Examples of materials capable of absorbing and releasing metal ions such as lithium ions include alloy-based negative electrode active materials such as Si and Sn, carbon materials such as graphite, and lithium titanate (Li4Ti5O 12 The negative electrode active material may be in the form of, for example, particles or a sheet.

[0045] For the solid electrolyte, conductive additive, and binder that can be contained in the negative electrode active material layer, the description in the "<Positive electrode active material layer>" above can be referred to.

[0046] <Negative electrode current collector layer> Examples of materials used for the negative electrode current collector layer include, but are not limited to, Cu, Ni, Cr, Au, Pt, Ag, Al, Fe, Ti, Zn, Co, stainless steel, and carbon sheet. The negative electrode current collector layer may be in the form of, for example, a foil, a plate, or a mesh. The negative electrode current collector layer may have a negative electrode tab for connection to a negative electrode current collector terminal.

[0047] <Laminating film> The laminate film is not particularly limited, but may have a fusion layer, a metal layer, and a resin layer in this order.

[0048] (fusion layer) Examples of materials for the fusion layer include, but are not limited to, polyolefin resins such as polypropylene (PP) and polyethylene (PE). The thickness of the fusion layer is not particularly limited, but may be 30 μm or more, 40 μm or more, or 50 μm or more, or 110 μm or less, 100 μm or less, or 90 μm or less.

[0049] (metal layer) Examples of materials for the metal layer include, but are not limited to, aluminum, aluminum alloys, stainless steel, etc. The thickness of the metal layer is not particularly limited, but may be 20 μm or more, 30 μm or more, or 40 μm or more, or 70 μm or less, 60 μm or less, or 50 μm or less.

[0050] (resin layer) Examples of materials for the resin layer include, but are not limited to, polyethylene terephthalate, nylon, etc. The thickness of the resin layer is not particularly limited, but may be 70 μm or more, 80 μm or more, or 90 μm or more, or 270 μm or less, 250 μm or less, or 230 μm or less.

[0051] <Battery uses, etc.> The battery in the present disclosure is not particularly limited, and may be a lithium-ion secondary battery. The battery in the present disclosure may be, for example, an in-vehicle battery, or may be used as a power source for a moving body other than a vehicle (for example, a train, a ship, or an airplane), or may be used as a power source for an electrical appliance such as an information processing device.

[0052] While embodiments of the current collecting terminal and battery of the present disclosure have been described, those skilled in the art will recognize that modifications may be made without departing from the scope of the claims. [Explanation of symbols]

[0053] 100 batteries 110 Current collector terminal 110a Conductive main body 110b Resin buffer section 120 Electrode laminate 120a Side part 130 Laminating Film 130a Convex fused part 140 Current collecting foil

Claims

[Claim 1] A current collecting terminal for forming a battery by being wrapped and covered with a laminate film together with an electrode stack, the current collecting terminal has a conductive main body portion and a resin buffer portion, The resin buffer portion is disposed on at least a part of the surface to be fused to the laminate film. Current collector terminal.

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