Battery

Abstract

To provide a battery capable of suppressing occurrence of cracks in a laminate film near a convex fused part due to thermal shock at high temperatures.SOLUTION: There is provided a battery including an electrode laminate, a current collector terminal 110 connected to a current collector foil of the electrode laminate, and a laminate film 130 that winds the electrode laminate and the current collector terminal 110 to seal the electrode laminate. The current collector terminal 110 has a first surface to face a side part of the electrode laminate, a second surface facing the first surface, and four surfaces along outer edges of the first surface and the second surface. The current collector terminal 110 includes a protrusion 110c on at least a part of the four surfaces. Thus, a convex fused part 130a where fusion layers of the laminate film 130 are fused together is formed so as to cover the protrusion 110c.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to batteries. [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] 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, in a battery such as that disclosed in Patent Document 1, cracks may occur near the fused portion where the inner surfaces of the laminate film are fused together (hereinafter referred to as the convex fused portion) due to thermal shock at high temperatures. This is thought to be because, at high temperatures, the fused layer of the laminate film, particularly near the convex fused portion, experiences large thermal expansion, which causes the metal layer of the laminate film to fracture.

[0006] Therefore, an object of the present disclosure is to provide a battery that can suppress the occurrence of cracks in the metal layer of the laminate film near the convex fused portion due to thermal shock at high temperatures. [Means for solving the problem]

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

[0008] <Aspect 1> an electrode stack; a current collecting terminal 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 has a first surface facing the side surface of the electrode stack, a second surface facing the first surface, and four surfaces along outer edges of the first surface and the second surface; When the battery is viewed from the side of the current collecting terminal, an outer edge of the current collecting terminal is located inside an outer edge of the electrode stack, The current collecting terminal has a protrusion on at least a part of the four faces, and a convex fused portion formed by fusion layers of the laminate film is fused to each other so as to cover the protrusion. battery. <Aspect 2> 2. The battery of embodiment 1, wherein the current collecting terminal has the protrusion around at least one corner formed by the four faces. [Effects of the Invention]

[0009] According to the battery of the present disclosure, it is possible to suppress the occurrence of cracks in the metal layer of the laminate film near the convex fused portion due to thermal shock at high temperatures. [Brief explanation of the drawings]

[0010] [Figure 1]FIG. 1 is a schematic diagram illustrating an electrode stack included in a battery according to the present disclosure. [Figure 2] FIG. 2 is a schematic diagram illustrating the battery 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] "battery" The battery of the present disclosure comprises: an electrode stack; a current collecting terminal 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 has a first surface facing the side surface of the electrode stack, a second surface facing the first surface, and four surfaces along outer edges of the first surface and the second surface; When the battery is viewed from the side of the current collecting terminal, an outer edge of the current collecting terminal is located inside an outer edge of the electrode stack, The current collecting terminal has a protrusion on at least a part of the four faces, and a convex fused portion is formed by fusion of the fusion layers of the laminate film so as to cover the protrusion.

[0014] According to the battery of the present disclosure, it is possible to suppress the occurrence of cracks in the metal layer of the laminate film near the convex fused portion due to thermal shock at high temperatures.

[0015] The present inventors have found that the occurrence of cracks in the metal layer of the laminate film at the convex fusion portion due to thermal shock during fusion can be suppressed by having a protrusion in the current collecting terminal within the convex fusion portion. Without being limited by theory, it is speculated that the current collecting terminal has a protrusion, and the fusion layers of the laminate film are fused to each other to form a convex fusion portion covering the protrusion, thereby reducing the volume of the fusion layer required at the convex fusion portion and making it difficult for stress to concentrate on the fusion layer, thereby suppressing thermal expansion of the fusion layer and suppressing the occurrence of cracks in the metal layer of the laminate film near the convex fusion portion.

[0016] FIG. 1 is a schematic diagram showing one embodiment of an electrode stack included in a battery of the present disclosure, but the present disclosure is not limited to this embodiment.

[0017] In FIG. 1A, the electrode stack 120 includes a current collecting foil 140 on a side surface 120a of the electrode stack 120. The current collecting terminal 110 is connected to the current collecting foil 140 disposed on the side surface 120a of the electrode stack 120. The current collecting terminal 110 has a first surface 110a facing the side surface 120a of the electrode stack 120, a second surface 110b facing the first surface 110a, and four surfaces along the outer edges of the first surface 110a and the second surface 110b, and has a protrusion 110c on one of the four surfaces. FIG. 1B is a side view of the electrode stack 120 from the side of the current collecting terminal 110, with the outer edge of the current collecting terminal 110 being located inside the outer edge of the electrode stack 120.

[0018] FIG. 2 is a schematic diagram showing one embodiment of the battery of the present disclosure, but is not limited to this embodiment.

[0019] The electrode laminate 120 and the current collecting terminal 110 are wound with a laminate film 130, and the electrode laminate 120 is sealed to form a battery 100. In FIG. 2A, the current collecting terminal 110 of the battery 100 has a protrusion 110c on one of four surfaces along the outer edges of the first surface 110a and the second surface 110b. A convex fused portion 130a is formed by fusing the fusion layers of the laminate film 130 together to cover the protrusion 110c of the current collecting terminal 110. By having the protrusion 110c within the convex fused portion 130a of the current collecting terminal 110, it is possible to suppress the occurrence of cracks in the laminate film near the convex fused portion. If the current collecting terminal 110 did not have a protrusion, as shown in FIG. 2B, it is presumed that thermal expansion of the fusion layer near the convex fused portion 130a would be large, causing the laminate film 130 to break.

[0020] The length 110d of the protrusion of the current collecting terminal is the distance from the surface of the current collecting terminal to the tip of the protrusion on the side where the protrusion is located. The length of the protrusion of the current collecting terminal is not particularly limited, but may be 0.1 mm or more, 0.2 mm or more, 0.3 mm or more, 0.4 mm or more, or 0.5 mm or more, or 1.0 mm or less, 0.9 mm or less, 0.8 mm or less, 0.7 mm or less, 0.6 mm or less, or 0.5 mm or less, from the viewpoint of suppressing the occurrence of cracks in the laminate film near the convex fused portion.

[0021] The length 130b of the protruding fused portion is the distance from the surface of the laminate film to the tip of the protruding fused portion on the side of the laminate film on which the protruding fused portion is located. The length of the protruding fused portion is not particularly limited, but may be 0.2 mm or more, 0.4 mm or more, 0.6 mm or more, 0.8 mm or more, or 1.0 mm or more, or 1.5 mm or less, 1.2 mm or less, or 1.0 mm or less.

[0022] In the battery of the present disclosure, the current collecting terminal preferably has the above-mentioned protrusion around at least one corner formed by the four faces, although this is not particularly limited, and more preferably has the above-mentioned protrusion around all corners formed by the four faces.

[0023] FIG. 3 is a schematic diagram showing one embodiment of the battery of the present disclosure, but is not limited to this embodiment.

[0024] In FIG. 3A, the current collector terminal 110 of the battery 100 has a protrusion 110c around one of the corners formed by the four surfaces. A convex fused portion 130a is formed by the fusion layers of the laminate film 130 fused together to cover the protrusion 110c. In FIG. 3B, the current collector terminal 110 of the battery 100 has protrusions 110c around all of the corners formed by the four surfaces. As in FIG. 3A, convex fused portions 130a are formed by the fusion layers of the laminate film 130 fused together to cover the protrusion 110c. When a tab structure is to be formed around the corners of the current collector terminal of the battery, having the protrusion around at least one corner formed by the four surfaces results in the convex fused portion having a tab structure. This makes it possible to suppress cracks in the laminate film near the convex fused portion due to thermal shock during fusion, further improving the productivity of the battery.

[0025] <Battery components> Each component of the battery will be described below.

[0026] <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.

[0027] <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 have, for example, a foil, plate, or mesh shape. The positive electrode current collector layer may have a current collecting tab for connection to a positive electrode current collecting terminal.

[0028] <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.

[0029] (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 / 3 O2), but is not limited to these. The positive electrode active material may be in the form of particles, for example.

[0030] (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).

[0031] (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.

[0032] (binder) The binder may be, for example, but not limited to, materials such as polyvinylidene fluoride (PVdF), styrene butadiene rubber (SBR), and the like.

[0033] <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.

[0034] <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.

[0035] (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.

[0036] (separator) The separator is not particularly limited, but may be a polyolefin-based, polyamide-based, polyimide-based nonwoven fabric, or the like.

[0037] <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.

[0038] (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.

[0039] 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.

[0040] <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 current collecting tab for connection to a negative electrode current collecting terminal.

[0041] <Collector terminal> The current collecting terminal may be electrically connected to the current collecting foil of the electrode laminate, for example, the current collecting foil of the positive electrode current collecting layer or the negative electrode current collecting layer, although the material of the current collecting terminal is not particularly limited, and examples thereof include metals such as stainless steel (SUS).

[0042] <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.

[0043] (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.

[0044] (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.

[0045] (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.

[0046] <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.

[0047] While embodiments of the 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]

[0048] 100 batteries 110 Current collector terminal 110a First Side 110b Second Side 110c protrusion 110d protrusion length 120 Electrode laminate 120a Side part 130 Laminating Film 130a Convex fused part 130b Length of convex fused portion 140 Current collecting foil

Claims

[Claim 1] an electrode stack; a current collecting terminal connected to the current collecting foil of the electrode stack; and a laminate film that wraps the electrode stack and the current collecting terminals and seals the electrode stack; A battery having the current collecting terminal has a first surface facing a side surface of the electrode stack, a second surface facing the first surface, and four surfaces along outer edges of the first surface and the second surface, When the battery is viewed from the side of the current collector terminal, an outer edge of the current collector terminal is located inside an outer edge of the electrode stack, The current collecting terminal has a protrusion on at least a part of the four faces, and a convex fused portion formed by fusion layers of the laminate film is fused to each other so as to cover the protrusion. battery.

Images