Battery manufacturing method

Abstract

To provide a battery manufacturing method capable of suppressing occurrence of cracks in a metal layer.SOLUTION: A battery manufacturing method includes the steps of: forming a resin layer 140 by an injection molding to cover an electrode laminate 130 and a collector terminal 110 connected to a current collector foil 120 of the electrode laminate 130; and forming a metal layer 150 by an injection molding to cover the resin layer 140. The material for resin layer 140 is preferably polyolefin resin, and the material for metal layer 150 is preferably aluminum or aluminum alloy.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a method for manufacturing a battery. [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 member such as a laminate film, and the following batteries are known.

[0003] Patent Document 1 discloses a battery comprising an electrode assembly (electrode laminate), a side member (current collecting terminal) 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] In the manufacture of the above-described battery, when the electrode laminate and the current collecting terminals connected to the current collecting foils of the electrode laminate are covered and sealed with a laminate film as an exterior member, cracks may occur in the metal layer of the laminate film. This is thought to be because wrinkles occur in the laminate film when the electrode laminate and the like are covered and sealed with the laminate film, and stress is concentrated in the wrinkled areas.

[0006] Therefore, an object of the present disclosure is to provide a method for manufacturing a battery that can suppress the occurrence of cracks in the metal layer. [Means for solving the problem]

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

[0008] <Aspect 1> A method for manufacturing a battery, including: forming a resin layer by injection molding so as to cover the electrode laminate and the current collecting terminal connected to the current collecting foil of the electrode laminate; and A metal layer is formed by injection molding so as to cover the resin layer. <Aspect 2> The material of the resin layer contains a polyolefin resin, and The material of the metal layer comprises aluminum or an aluminum alloy. A method for producing the battery of embodiment 1. [Effects of the Invention]

[0009] According to the battery manufacturing method of the present disclosure, the occurrence of cracks in the metal layer can be suppressed. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic perspective view for explaining the method for manufacturing a battery according to the present disclosure. [Figure 2] FIG. 2 is a schematic side view for explaining the manufacturing method of 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 manufacturing method> The method for manufacturing a battery according to the present disclosure includes: forming a resin layer by injection molding so as to cover the electrode laminate and the current collecting terminal connected to the current collecting foil of the electrode laminate; and forming a metal layer by injection molding so as to cover the resin layer; Includes.

[0014] According to the battery manufacturing method of the present disclosure, the occurrence of cracks in the metal layer can be suppressed.

[0015] The present inventors have discovered that the occurrence of cracks in the metal layer can be suppressed by injection molding the resin layer and metal layer that seal the electrode laminate. Without being limited by theory, it is speculated that by forming a resin layer by injection molding so as to cover the electrode laminate and the current collecting terminals connected to the current collecting foil of the electrode laminate, and then forming a metal layer by injection molding so as to cover the resin layer, the occurrence of wrinkles in the resin layer and the metal layer can be suppressed, thereby suppressing the occurrence of cracks in the metal layer.

[0016] Fig. 1 is a schematic perspective view showing one embodiment of the method for producing a battery according to the present disclosure, but is not limited to this example. Fig. 2 is a schematic side view showing one embodiment of the method for producing a battery according to the present disclosure, but is not limited to this example.

[0017] FIG. 1A shows an electrode laminate 130. The electrode laminate 130 has a current collecting foil 120 on a side surface portion 130a of the electrode laminate 130. A current collecting terminal 110 is connected to the current collecting foil 120 of the electrode laminate 130. In the method for manufacturing a battery according to the present disclosure, first, as shown in FIG. 1B, a resin layer 140 is formed by injection molding so as to cover the electrode laminate 130 and the current collecting terminal 110 connected to the current collecting foil 120 of the electrode laminate 130. Next, as shown in FIG. 1C, a metal layer 150 is formed by injection molding so as to cover the resin layer 140, thereby forming the battery 100.

[0018] 2 is a schematic diagram of an electrode laminate and a current collecting terminal connected to a current collecting foil of the electrode laminate, viewed from the side of the current collecting terminal. As described above, the method for manufacturing a battery according to the present disclosure involves forming a resin layer 140 by injection molding so as to cover the electrode laminate and the current collecting terminal 110, as shown in FIG. 2A. Next, as shown in FIG. 2B, a metal layer 150 is formed by injection molding so as to cover the resin layer 140, thereby forming a battery.

[0019] By forming the resin layer and the metal layer by injection molding, the occurrence of wrinkles in the resin layer and the metal layer can be suppressed, thereby suppressing the occurrence of cracks in the metal layer. On the other hand, when the electrode stack and the current collecting terminals are covered and sealed with a laminate film, wrinkles may occur in the laminate film, and stress may concentrate in the wrinkled areas, which may cause cracks in the metal layer.

[0020] In the battery manufacturing method of the present disclosure, although not particularly limited, forming a protective resin layer by injection molding so as to cover the metal layer; It may further include.

[0021] In the above-described FIG. 2, after forming the metal layer 150, a protective resin layer 160 may be formed by injection molding so as to cover the metal layer 150, as shown in FIG. 2C.

[0022] <Injection molding> The injection molding method is not particularly limited, but any known injection molding method can be appropriately adopted.

[0023] (Injection molding of resin layer) In the injection molding of the resin layer, the temperature at which the material constituting the resin layer is melted is not particularly limited, but may be 200°C or higher, 220°C or higher, or 240°C or higher, or 320°C or lower, 300°C or lower, or 280°C or lower.

[0024] The mold temperature during injection molding of the resin layer is not particularly limited, but may be 10°C or higher, 20°C or higher, or 30°C or higher, and may be 200°C or lower, 190°C or lower, or 180°C or lower.

[0025] The injection speed in injection molding of the resin layer is not particularly limited, but may be 5 mm / sec or more, 10 mm / sec or more, or 15 mm / sec or more, or may be 30 mm / sec or less, 25 mm / sec or less, or 20 mm / sec or less.

[0026] The holding pressure during injection molding of the resin layer is not particularly limited, but may be 10 MPa or more, or 20 MPa or more, or 50 MPa or less, or 40 MPa or less.

[0027] The screw rotation speed during injection molding of the resin layer is not particularly limited, but may be 100 rpm or more, 110 rpm or more, or 120 rpm or more, or 150 rpm or less, 140 rpm or less, or 130 rpm or less.

[0028] (metal layer injection molding) In injection molding of the metal layer, the temperature at which the material constituting the metal layer is melted is not particularly limited, but may be 500°C or higher, 550°C or higher, or 600°C or higher, or 800°C or lower, or 700°C or lower.

[0029] The mold temperature during injection molding of the metal layer is not particularly limited, but may be 10°C or higher, 20°C or higher, or 30°C or higher, and may be 200°C or lower, 190°C or lower, or 180°C or lower.

[0030] For other conditions in injection molding of the metal layer, the above description of "(Injection molding of the resin layer)" can be referred to.

[0031] (Injection molding of protective resin layer) In the injection molding of the protective resin layer, the temperature at which the material constituting the protective resin layer is melted is not particularly limited, and the mold temperature in the injection molding of the protective resin layer is not particularly limited.

[0032] <Battery manufacturing method; each component> Each step in the battery manufacturing method will be described below.

[0033] In the present disclosure, the battery has at least a resin layer and a metal layer formed by injection molding, and may have a resin layer, a metal layer, and a protective resin layer in this order. The resin layer and the metal layer may be used as exterior components of the battery, or the resin layer, the metal layer, and the protective resin layer may be used as exterior components of the battery.

[0034] <Resin layer> The material of the resin layer is not particularly limited, but may be a polyolefin resin. Examples of polyolefin resins include, but are not limited to, polypropylene (PP) and polyethylene (PE). The material of the resin layer is not particularly limited, but preferably contains a polyolefin resin.

[0035] The thickness of the resin layer is not particularly limited, but may be 30 μm or more, 40 μm or more, or 50 μm or more, and may be 110 μm or less, 100 μm or less, or 90 μm or less.

[0036] <Metal layer> Examples of materials for the metal layer include, but are not limited to, aluminum, aluminum alloys, stainless steel, etc. The material for the metal layer is not particularly limited, but preferably includes aluminum or an aluminum alloy.

[0037] 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, and may be 70 μm or less, 60 μm or less, or 50 μm or less.

[0038] <Protective resin layer> Examples of materials for the protective resin layer include, but are not limited to, polyethylene terephthalate and nylon.

[0039] <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.

[0040] <Positive electrode current collector layer> The material used for the positive electrode current collector layer is not particularly limited, and any material commonly used for a battery positive electrode current collector can be appropriately adopted. 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 a coating layer on its surface for purposes such as adjusting resistance. The positive electrode current collector layer may also be a metal foil or a substrate on which the above metals are plated or vapor-deposited.

[0041] The shape of the positive electrode current collector layer is not particularly limited, but examples thereof include foil, plate, mesh, etc. Among these, foil is preferred.

[0042] The thickness of the positive electrode current collector layer is not particularly limited, but may be 0.1 μm or more, or 1 μm or more, and may be 1 mm or less, or 100 μm or less.

[0043] <Cathode active material layer> The positive electrode active material layer contains at least a positive electrode active material, and may further contain, optionally, a solid electrolyte, a conductive additive, a binder, etc. The positive electrode active material layer may also contain various other additives. The contents of the positive electrode active material, solid electrolyte, conductive additive, binder, etc. in the positive electrode active material layer may be appropriately determined depending on the desired battery performance. For example, when the entire positive electrode active material layer (total solid content) is taken as 100 mass%, the content of the positive electrode active material may be 40 mass% or more, 50 mass% or more, 60 mass% or more, or 100 mass% or less, or 90 mass% or less.

[0044] (Cathode active material) The material of the positive electrode active material is not particularly limited as long as it can absorb and release lithium ions. Examples of the positive electrode active material include lithium cobalt oxide (LiCoO), lithium nickel oxide (LiNiO), lithium manganese oxide (LiMnO), and nickel-cobalt-manganese oxide (NCM:LiCO 1 / 3 Ni 1 / 3 Mn 1 / 3 O2), lithium nickel-cobalt-aluminate (LiNi 0.8 (CoAl) 0.2 O2), Li 1+x Mn 2-x-y M y The material may be, but is not limited to, a different element-substituted Li-Mn spinel having a composition represented by O4 (M is one or more metal elements selected from Al, Mg, Co, Fe, Ni, and Zn).

[0045] The positive electrode active material may have a coating layer, although it is not particularly limited. The coating layer is a layer containing a substance that has lithium ion conductivity, low reactivity with the positive electrode active material and the solid electrolyte, and can maintain the shape of the coating layer without flowing even when in contact with the active material and the solid electrolyte. Specific examples of materials that constitute the coating layer include LiNbO3 and Li4Ti5O 12 , Li3PO4, etc., but are not limited to these.

[0046] The shape of the positive electrode active material is not particularly limited as long as it is a general shape for a positive electrode active material of a battery. The positive electrode active material may be, for example, in the form of particles. The positive electrode active material may be in the form of primary particles or secondary particles formed by agglomeration of a plurality of primary particles. The average particle diameter D of the positive electrode active material 50 The average particle size D may be, for example, 1 nm or more, 5 nm or more, or 10 nm or more, and may be 500 μm or less, 100 μm or less, 50 μm or less, or 30 μm or less. 50 is the particle size (median size) at 50% cumulative value in the volume-based particle size distribution determined by laser diffraction / scattering method.

[0047] (solid electrolyte) The material of the solid electrolyte is not particularly limited, and may be, for example, a sulfide solid electrolyte, an oxide solid electrolyte, or a polymer electrolyte.

[0048] Examples of sulfide solid electrolytes include, but are not limited to, sulfide-based amorphous solid electrolytes, sulfide-based crystalline solid electrolytes, and argyrodite-type solid electrolytes. Specific examples of sulfide solid electrolytes include Li2S-P2S5-based (Li7P3S 11 , Li3PS4, Li8P2S9, etc.), Li2S-SiS2, LiI-Li2S-SiS2, LiI-Li2S-P2S5, LiI-LiBr-Li2S-P2S5, Li2S-P2S5-GeS2(Li 13 GeP3S 16 , Li 10 GeP2S 12 etc.), LiI-Li2S-P2O5, LiI-Li3PO4-P2S5, Li 7-xPS 6-x Cl x etc.; or combinations thereof, but are not limited to these.

[0049] An example of an oxide solid electrolyte is Li7La3Zr2O 12 , Li 7-x La3Zr 1-x Nb x O 12 , Li 7-3x La3Zr2Al x O 12 , Li 3x La 2 / 3-x TiO3, Li 1+x Al x Ti 2-x (PO4)3, Li 1+x Al x Ge 2-x (PO4)3, Li3PO4, or Li 3+x PO 4-x N x (LiPON), etc.; or combinations thereof.

[0050] The sulfide solid electrolyte and the oxide solid electrolyte may be glass or crystallized glass (glass ceramics).

[0051] Examples of polymer electrolytes include, but are not limited to, polyethylene oxide (PEO), polypropylene oxide (PPO), and copolymers thereof.

[0052] (Conductive additive) The conductive additive is not particularly limited. The conductive additive may be, for example, vapor grown carbon fiber (VGCF), acetylene black (AB), ketjen black (KB), carbon nanotube (CNT), carbon nanofiber (CNF), etc., but is not limited thereto. The conductive additive may be, for example, particulate or fibrous, and its size is not particularly limited. The conductive additive is not particularly limited, but one type may be used alone, or two or more types may be used in combination.

[0053] (binder) The binder is not particularly limited. The binder may be, for example, polyvinylidene fluoride (PVdF), butadiene rubber (BR), polytetrafluoroethylene (PTFE), styrene butadiene rubber (SBR), or other materials, but is not limited to these. The binder is not particularly limited, and one type may be used alone, or two or more types may be used in combination.

[0054] The shape of the positive electrode active material layer is not particularly limited, and may be, for example, a substantially flat sheet-like positive electrode active material layer. The thickness of the positive electrode active material layer is not particularly limited, and may be, for example, 0.1 μm or more, 1 μm or more, or 10 μm or more, and may be 2 mm or less, 1 mm or less, or 500 μm or less.

[0055] The positive electrode active material layer can be produced by applying a known method. For example, the positive electrode active material layer can be easily formed by dry or wet molding a positive electrode composite containing the above-mentioned various components. The positive electrode active material layer may be formed together with the positive electrode current collector layer or may be formed separately from the positive electrode current collector layer.

[0056] <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 an electrolyte layer. The solid electrolyte layer contains at least a solid electrolyte and may also contain a conductive additive, a binder, etc. as necessary.

[0057] For the solid electrolyte, the conductive additive, and the binder, reference can be made to the above description of "<Positive electrode active material layer>".

[0058] The thickness of the solid electrolyte layer is not particularly limited, but may be, for example, 0.1 μm or more, 1 μm or more, or 10 μm or more, and may be 2 mm or less, 1 mm or less, or 500 μm or less.

[0059] The solid electrolyte layer can be easily formed, for example, by dry or wet molding a solid electrolyte mixture containing the above-mentioned solid electrolyte and a binder.

[0060] <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.

[0061] (electrolyte) The electrolyte is not particularly limited, but preferably contains a supporting salt and a solvent.

[0062] The supporting salt (lithium salt) of the electrolyte solution having lithium ion conductivity is not particularly limited, but examples thereof include inorganic lithium salts and organic lithium salts. Examples of inorganic lithium salts include, but are not limited to, LiPF, LiBF, LiClO, and LiAsF. Examples of organic lithium salts include, but are not limited to, LiCF, SO, LiN(CF, SO), LiN(CF, SO), LiN(FSO), LiC(CF, SO), and LiC(CF, SO).

[0063] The solvent used in the electrolyte solution is not particularly limited, but examples thereof include cyclic carbonates, chain carbonates, etc. Examples of cyclic carbonates include, but are not limited to, ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), etc. Examples of chain carbonates include, but are not limited to, dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), etc. The electrolyte solution is not particularly limited, but one type may be used alone, or two or more types may be used in combination.

[0064] (separator) The separator is not particularly limited, and any separator commonly used for batteries can be appropriately used, such as a polyolefin-based, polyamide-based, or polyimide-based nonwoven fabric.

[0065] <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. The negative electrode active material layer may also contain various other additives. The contents of the negative electrode active material, solid electrolyte, conductive additive, binder, and the like in the negative electrode active material layer may be appropriately determined depending on the desired battery performance. For example, when the entire negative electrode active material layer (total solid content) is taken as 100 mass%, the content of the negative electrode active material may be 40 mass% or more, 50 mass% or more, or 60 mass% or more, or may be 100 mass% or less, or 90 mass% or less.

[0066] (Negative electrode active material) As the negative electrode active material, various substances can be used that have a potential (charge / discharge potential) for absorbing and releasing lithium ions that is lower than that of the positive electrode active material of the present disclosure. The material for 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, carbon materials, and lithium titanate (Li4Ti5O 12 ) and the like can be mentioned, but are not limited to these.

[0067] The alloy-based negative electrode active material is not particularly limited, and examples thereof include Si alloy-based negative electrode active materials and Sn alloy-based negative electrode active materials. Examples of Si alloy-based negative electrode active materials include silicon, silicon oxide, silicon carbide, silicon nitride, and solid solutions thereof. The Si alloy-based negative electrode active material may contain metal elements other than silicon, such as Fe, Co, Sb, Bi, Pb, Ni, Cu, Zn, Ge, In, Sn, and Ti. Examples of Sn alloy-based negative electrode active materials include tin, tin oxide, tin nitride, and solid solutions thereof. The Sn alloy-based negative electrode active material may contain metal elements other than tin, such as Fe, Co, Sb, Bi, Pb, Ni, Cu, Zn, Ge, In, Ti, and Si.

[0068] The carbon material is not particularly limited, and examples thereof include hard carbon, soft carbon, graphite, and the like.

[0069] The shape of the negative electrode active material is not particularly limited, and may be any shape commonly used for negative electrode active materials in batteries. The negative electrode active material may be, for example, in the form of particles or a sheet.

[0070] 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.

[0071] The shape of the negative electrode active material layer is not particularly limited, and may be, for example, a substantially flat sheet-like negative electrode active material layer. The thickness of the negative electrode active material layer is not particularly limited, and may be, for example, 0.1 μm or more, 1 μm or more, or 10 μm or more, and may be 2 mm or less, 1 mm or less, or 500 μm or less.

[0072] The negative electrode active material layer can be produced by applying a known method. For example, the negative electrode active material layer can be easily formed by dry or wet molding a negative electrode composite containing the above-mentioned various components. The negative electrode active material layer may be formed together with the negative electrode current collector layer or may be formed separately from the negative electrode current collector layer.

[0073] <Negative electrode current collector layer> The material used for the negative electrode current collector layer is not particularly limited, and any material commonly used for a negative electrode current collector in a battery can be appropriately used. 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 a carbon sheet. The negative electrode current collector layer may have a coating layer on its surface for the purpose of adjusting resistance, etc.

[0074] The shape of the negative electrode current collector layer is not particularly limited, but examples thereof include foil, plate, mesh, etc. Among these, foil is preferred.

[0075] The thickness of the negative electrode current collector layer is not particularly limited, but may be 0.1 μm or more, or 1 μm or more, and may be 1 mm or less, or 100 μm or less.

[0076] <Collector terminal> The current collecting terminal is connected to the current collecting foil of the electrode laminate. The current collecting terminal may be electrically connected to the current collecting foil of the positive electrode current collecting layer or the negative electrode current collecting layer, for example. The material of the current collecting terminal is not particularly limited, but metals such as aluminum and stainless steel (SUS) can be used.

[0077] <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.

[0078] While embodiments of the disclosed method for manufacturing a battery 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]

[0079] 100 batteries 110 Current collector terminal 120 Current collecting foil 130 Electrode laminate 130a Side part 140 Resin layer 150 metal layer 160 protective resin layer

Claims

1. A method of manufacturing a battery, including: forming a resin layer by injection molding so as to cover the electrode laminate and the current collecting terminals connected to the current collecting foils of the electrode laminate; and forming a metal layer by injection molding so as to cover the resin layer;

2. The material of the resin layer includes a polyolefin resin, and the material of the metal layer comprises aluminum or an aluminum alloy; A method for manufacturing the battery according to claim 1.

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