Collector terminal and laminate battery

Abstract

To provide a collector terminal for a laminate battery that can provide high adhesion between a laminate exterior body and the collector terminal.SOLUTION: A collector terminal is for a laminate battery. The laminate battery includes a laminate exterior body and an electrode laminate housed in the laminate exterior body. The collector terminal includes: a collector connection part for electrically connecting to a current collector of the electrode laminate; an external terminal connection part for electrically connecting to an external terminal; and a fusion part between the collector connection part and the external terminal connection part for fusion-bonding with the laminate exterior body. The fusion part is at least partially covered with an anodized coating.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Patent Document 1 discloses a secondary battery comprising a power generating element and an exterior part that houses the power generating element, the exterior part having a cylindrical part with openings on two opposing sides, a cap terminal that is placed in each of the openings, and a resin that is placed between the cylindrical part and the cap terminal, the cylindrical part and the cap terminal being integrated with the resin, and the current collector of the power generating element and the cap terminal being electrically connected. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-80466 Summary of the Invention [Problem to be solved by the invention]

[0004] The laminate battery disclosed in Patent Document 1 has an electrode laminate and current collecting terminals electrically connected to the current collectors of the electrode laminate. Furthermore, such a laminate battery has a structure in which the electrode laminate is sealed by the laminate exterior body and the current collecting terminals.

[0005] In the above-described configuration, the laminate exterior body is adhered to the current collecting terminal to seal the electrode stack. However, external stress applied to the laminate battery or stress due to the difference in linear expansion during heating and cooling can reduce the adhesion between the laminate exterior body and the current collecting terminal. Poor adhesion between the laminate exterior body and the current collecting terminal can cause peeling between the laminate exterior body and the current collecting terminal, which can impair the hermetic sealing of the electrode stack, for example.

[0006] An object of the present disclosure is to provide a current collector terminal for a laminate battery that can provide high adhesion between the laminate exterior body and the current collector terminal. [Means for solving the problem]

[0007] The present inventors have found that the above object can be achieved by the following means: <<Aspect 1>> A current collecting terminal for a laminated battery, comprising: the laminate battery has a laminate exterior body and an electrode stack housed in the laminate exterior body, The current collecting terminal is a current collector connection portion for electrically connecting to a current collector of the electrode laminate; an external terminal connection portion for electrically connecting to an external terminal; and a fusion portion between the current collector connection portion and the external terminal connection portion for fusion bonding to the laminate exterior body; and The fusion portion is at least partially covered with an anodic oxide coating. Current collector terminal. <<Aspect 2>> an electrode stack; The current collecting terminal according to aspect 1, and It has a laminate exterior body, the current collector connection portion of the current collector terminal is electrically connected to the current collector of the electrode stack, the laminate exterior body is fused to the fusion portion of the current collector terminal such that the external terminal connection portion is exposed to the outside of the laminate exterior body and the current collector connection portion of the current collector terminal and the electrode stack are sealed, the fusion material constituting the laminate exterior body penetrates into the pores of the anodized coating of the current collecting terminal; Laminated battery. Aspect 3 3. The laminate battery of claim 2, wherein the fusion material is an acid-modified polypropylene. Aspect 4 A method for manufacturing a laminate battery, comprising: Providing the current collecting terminal according to aspect 1 or 2; electrically connecting the current collector connection portion of the current collector terminal to the current collector of the electrode stack; the current collector connection portion and the fused portion of the current collector terminal, and the electrode stack are housed inside the laminate exterior body; applying pressure to a portion of the laminate exterior body that overlaps with the fused portion while heating the laminate exterior body so that the fusion material constituting the laminate exterior body penetrates into the pores of the anodized coating, thereby fusing the laminate exterior body and the fused portion, thereby sealing the current collector connection portion of the current collector terminal and the electrode stack; A method comprising: Aspect 5 A method according to aspect 4, wherein the heating temperature is 200°C to 300°C, and the pressurizing pressure is 30 MPa to 100 MPa. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to provide a current collector terminal for a laminate battery that can provide high adhesion between the laminate exterior body and the current collector terminal. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic diagram of a current collecting terminal 10 according to one embodiment of the present disclosure. [Figure 2] 1 is a schematic diagram of a laminated battery 1 according to one embodiment of the present disclosure. [Figure 3] 1A to 1C are schematic diagrams illustrating a part of a method for manufacturing a laminate battery 1 according to an embodiment of the present disclosure. [Figure 4] 1A to 1C are schematic diagrams illustrating a part of a method for manufacturing a laminate battery 1 according to an embodiment of the present disclosure. [Figure 5] 1A to 1C are schematic diagrams illustrating a part of a method for manufacturing a laminate battery 1 according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0010] 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 present disclosure.

[0011] 1.Collector terminal The current collecting terminal of the present disclosure is a current collecting terminal for a laminate battery, the laminate battery having a laminate outer casing and an electrode stack housed within the laminate outer casing, the current collecting terminal having a current collector connection portion for electrically connecting to the current collector of the electrode stack, an external terminal connection portion for electrically connecting to an external terminal, and a fusion portion between the current collector connection portion and the external terminal connection portion for fusing to the laminate outer casing, and the fusion portion is at least partially covered with an anodic oxide coating.

[0012] Because the anodized coating is porous, when the current collector terminal is fused to the laminate exterior body, for example, by heat fusion, the material constituting the fusion layer of the laminate exterior body can penetrate into the pores of the anodized coating. This increases the adhesive area between the fusion portion and the laminate exterior body. Therefore, the current collector terminal of the present disclosure can have high adhesion to the laminate exterior body.

[0013] A current collector terminal according to the present disclosure has a configuration as shown in FIG. 1, for example. As shown in FIG. 1, the current collector terminal 10 according to the present disclosure has a current collector connection portion 11 and an external terminal connection portion 12. The current collector terminal 10 according to the present disclosure also has a fused portion 13 between the current collector connection portion 11 and the external terminal connection portion 12. The current collector connection portion 11 is a portion for electrically connecting to the current collector 21 of the electrode laminate 20 of the laminate battery 1 shown in FIG. 2, for example. The external terminal connection portion 12 is a member for electrically connecting to an external terminal. The external terminal is a terminal for electrically connecting the laminate battery 1 to an external circuit of the laminate battery 1. The fused portion 13 is a portion for fusion bonding to the laminate exterior body 30 of the laminate battery 1 shown in FIG. 2, for example. The laminate exterior body 30 is fused to the fused portion 13 at a portion 31 that overlaps with the fused portion 13. It should be noted that FIG. 1 is not intended to limit the current collecting terminal, laminate battery, and laminate battery manufacturing method of the present disclosure.

[0014] The shape of the current collector terminal is not particularly limited as long as it has a current collector connection portion, an external terminal connection portion, and a fused portion between the current collector connection portion and the external terminal connection portion, and the shape allows the fused portion and the laminate outer casing to seal the current collector connection portion and the battery stack when a laminate battery is constructed. The material of the current collector terminal is a conductive material that can be anodized. The material of the current collector terminal can be, for example, aluminum, zinc, titanium, iron, magnesium, or an alloy thereof, or stainless steel. Aluminum is particularly preferred as the material of the current collector terminal. The dimensions of the current collector terminal can be determined appropriately taking into account the structure and size of the laminate battery to be used.

[0015] The current collecting terminal of the present disclosure can be used, for example, in the laminate battery described below in "2. Laminate Battery."

[0016] 1-1. Current collector connection The current collector connection portion is a portion for electrically connecting to the current collector of the electrode laminate. From the viewpoint of improving the electrical connection between the current collector connection portion and the current collector of the electrode laminate, the current collector connection portion is preferably smooth.

[0017] The electrical connection between the current collector connector and the current collector of the electrode laminate may be achieved, for example, by direct physical contact, or the current collector of the electrode laminate may be joined to the current collector by, for example, ultrasonic bonding.

[0018] 1-2. External terminal connection part The external terminal connection portion is a portion for electrically connecting to an external terminal for connecting the laminate battery to a circuit external to the laminate battery. From the viewpoint of improving the electrical connection between the external terminal connection portion and the external terminal, the external terminal connection portion is preferably smooth.

[0019] The electrical connection between the external terminal connection portion and the external terminal may be realized by, for example, direct physical contact, or the external terminal connection portion and the external terminal may be joined by, for example, ultrasonic bonding.

[0020] 1-3. Fusion part The fusion portion is a portion for fusion bonding to the laminate exterior body. The fusion portion is disposed between the current collector connection portion and the external terminal connection portion. The fusion portion is at least partially covered with an anodic oxide coating.

[0021] The anodic oxide coating is porous. The pore diameter of the anodic oxide coating is not particularly limited, but may be, for example, 10 nm to 500 nm. The pore diameter of the anodic oxide coating may be 10 nm or more, 50 nm or more, or 100 nm or more, and may be 500 nm or less, 400 nm or less, or 300 nm or less.

[0022] The thickness of the anodic oxide coating is not particularly limited, but may be, for example, 1 μm to 20 μm. The thickness of the anodic oxide coating may be 1 μm or more, 3 μm or more, or 5 μm or more, and may be 20 μm or less, 15 μm or less, or 10 μm or less.

[0023] The method for forming the anodic oxide coating is not particularly limited, and it can be formed, for example, by a general anodizing process. More specifically, it can be formed by electrolysis in an electrolyte, using the precursor of the current collector terminal as the anode and carbon or the like as the counter electrode. The current collector connection portion and the external terminal connection portion must be conductive. Therefore, if the anodic oxide coating is formed on the entire surface of the precursor of the current collector terminal by anodizing, it is possible to remove the anodic oxide coating from the current collector connection portion and the external terminal connection portion by appropriate polishing or the like.

[0024] 2. Laminated battery The laminate battery of the present disclosure has an electrode laminate, a current collector terminal of the present disclosure, and a laminate exterior body, the current collector connection portion of the current collector terminal is electrically connected to the current collector of the electrode laminate, the external terminal connection portion is exposed to the outside of the laminate exterior body, and the current collector connection portion of the current collector terminal and the electrode laminate are sealed, and the fusion material that makes up the laminate exterior body penetrates into the pores of the anodized coating of the current collector terminal.

[0025] The laminated battery of the present disclosure has high adhesion between the fused portion of the collector terminal and the laminated outer casing, making it less likely to experience peeling between the laminated outer casing and the collector terminal due to external stress applied to the laminated battery or stress caused by the difference in linear expansion during heating and cooling.

[0026] FIG. 2 is a schematic diagram of a laminate battery 1 according to one embodiment of the present disclosure. As shown in FIG. 2, the laminate battery 1 of the present disclosure includes an electrode laminate 20, a current collector terminal 10 of the present disclosure, and a laminate exterior body 30. The current collector connection portion 11 of the current collector terminal 10 is electrically connected to the current collector 21 of the electrode laminate 20. The external terminal connection portion 12 is exposed to the outside of the laminate exterior body 30. The laminate exterior body 30 is fused to the fused portion 13 of the current collector terminal 10 so as to seal the current collector connection portion 11 of the current collector terminal 10 and the electrode laminate 20. The laminate exterior body 30 is fused to the fused portion 13 of the current collector terminal 10 at a portion 31 that overlaps with the fused portion 13 of the current collector terminal 10. The fusion material constituting the laminate exterior body 30 penetrates into the pores of the anodized coating of the current collector terminal 10. It should be noted that FIG. 2 is not intended to limit the current collecting terminal, laminate battery, and laminate battery manufacturing method of the present disclosure.

[0027] The laminate battery of the present disclosure may be a liquid-based battery or a solid-state battery. In the present disclosure, the term "solid-state battery" refers to a battery that uses at least a solid electrolyte as an electrolyte. Therefore, a solid-state battery may use a combination of a solid electrolyte and a liquid electrolyte as an electrolyte. The solid-state 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.

[0028] The battery of the present disclosure may be, for example, a lithium-ion secondary battery. Examples of uses of the battery include power sources for vehicles such as hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), electric vehicles (BEVs), gasoline-powered automobiles, and diesel-powered automobiles. In particular, the battery is preferably used as a driving power source for hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), or electric vehicles (BEVs). The battery of the present disclosure may also be used as a power source for mobile objects other than vehicles (for example, trains, ships, and aircraft), or as a power source for electrical appliances such as information processing devices.

[0029] 2-1. Electrode laminate The electrode laminate functions as a power generating element of a battery. The shape of the electrode laminate is not particularly limited, and may have, for example, a top surface, a bottom surface opposite the top surface, and four side surfaces connecting the top surface and the bottom surface. The shape of the top surface is not particularly limited, and examples thereof include quadrilaterals such as squares, rectangles, rhombuses, trapezoids, and parallelograms. The shape of the top surface may also be a polygon other than a quadrilateral, or may be a curved shape such as a circle. The shape of the bottom surface is the same as that of the top surface. The shape of the side surface is not particularly limited, and examples thereof include quadrilaterals such as squares, rectangles, rhombuses, trapezoids, and parallelograms.

[0030] The electrode laminate 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. Materials commonly used in the field of batteries can be used to form each layer.

[0031] 2-2.Laminate exterior body The laminate exterior body seals the electrode stack together with the current collecting terminal. Specifically, the laminate exterior body may be composed of one or more laminate films, and the electrode stack and the current collecting terminal may be wound together to seal the electrode stack together with the current collecting terminal. Alternatively, the laminate exterior body may be composed of first and second laminate films, and in this case, the first and second films may sandwich the electrode stack and the current collecting terminal from above and below in the stacking direction of the electrode stack, sealing the electrode stack together with the current collecting terminal.

[0032] The laminate exterior may have a fusion resin layer, a metal layer, and a protective resin layer in this order along the thickness direction. Examples of fusion materials constituting the fusion resin layer include olefin resins such as polypropylene (PP) and polyethylene (PE), or acid-modified versions of these. Acid-modified polypropylene is particularly preferred as the fusion material. Examples of materials for the metal layer include aluminum, aluminum alloys, and stainless steel. Examples of materials for the protective resin layer include polyethylene terephthalate (PET) and nylon. The thickness of the fusion resin layer is, for example, 40 μm or more and 100 μm or less. The thickness of the metal layer may be, for example, 30 μm or more and 60 μm or less. The thickness of the protective resin layer may be, for example, 20 μm or more and 60 μm or less. The thickness of the laminate film may be, for example, 80 μm or more and 250 μm or less.

[0033] 3. Manufacturing method of laminated batteries The manufacturing method of the present disclosure is a manufacturing method of the laminate battery of the present disclosure. The manufacturing method of the present disclosure includes the following steps: (A) providing a current collecting terminal of the present disclosure; (B) electrically connecting the current collector connection portion of the current collector terminal to the current collector of the electrode laminate; (C) housing the current collector connection portion and fusion portion of the current collector terminal and the electrode laminate inside a laminate exterior body; (D) The portion of the laminate outer casing that overlaps with the fused portion is heated and pressurized so that the fusion material that constitutes the laminate outer casing penetrates into the pores of the anodized coating, fusing the laminate outer casing and the fused portion, thereby sealing the current collector connection portion of the collector terminal and the electrode laminate.

[0034] Step (A) is to provide a current collecting terminal 1 of the present disclosure, for example as shown in FIG.

[0035] Step (B) is, for example, as shown in Fig. 3, to electrically connect the current collector connection portion 11 of the current collector terminal 10 and the current collector 21 of the electrode laminate 20. The electrical connection can be achieved, for example, by arranging the current collector connection portion 11 of the current collector terminal 10 so that it is in direct physical contact with the current collector 21 of the electrode laminate 20. Alternatively, the current collector connection portion 11 and the current collector 21 may be bonded with a conductive adhesive material, or may be bonded by ultrasonic bonding.

[0036] In step (C), as shown in FIG. 4, for example, a laminate outer casing 30 having the shape of a single laminate sheet is wound 200 around the electrode stack 20 and the current collector terminal 10, and the current collector connection portion 11 and fused portion 13 of the current collector terminal 10, as well as the electrode stack 20, are housed inside the laminate outer casing 30.

[0037] In step (D), as shown in Fig. 5, for example, a portion 31 of the laminate exterior body 30 that overlaps with the fused portion 13 is heated and pressurized 300. By heating and pressing 300, the fusion material that constitutes the laminate exterior body 30 penetrates into the pores of the anodized coating. This results in a particularly strong fusion bond between the laminate exterior body 30 and the fused portion 13. In step (D), the current collector connection portion 11 of the current collecting terminal 10 and the electrode stack 20 are sealed by the laminate exterior body 30 and the fused portion 13 of the current collecting terminal 10.

[0038] The heating temperature in step (D) may be any temperature at which the fusion material melts. The pressure applied may be any pressure at which the fusion material can penetrate into the pores of the anodic oxide coating at the fusion bonded portion. Specifically, the heating temperature is preferably 200°C to 300°C, and the pressure applied is preferably 30 MPa to 100 MPa. The heating temperature may be 200°C or higher, 220°C or higher, or 240°C or higher, and may be 300°C or lower, 280°C or lower, or 260°C or lower. A heating temperature of 200°C to 300°C provides fluidity particularly advantageous for the fusion material to penetrate into the pores of the anodic oxide coating while maintaining the fusion resin layer. The pressure applied may be 30 MPa or higher, 40 MPa or higher, or 50 MPa or higher, and 100 MPa or lower, 90 MPa or lower, or 80 MPa or lower. A pressure of 30 MPa to 100 MPa is particularly advantageous for allowing the adhesive material to penetrate into the pores of the anodized coating while maintaining the adhesive resin layer.

[0039] 3 to 5 are not intended to limit the current collecting terminal, laminate battery, and laminate battery manufacturing method of the present disclosure. [Explanation of symbols]

[0040] 1 Laminated battery 10 Current collector terminal 11 Current collector connection 12 External terminal connection part 13 Fusion part 20 Electrode laminate 21 Current collector 30 Laminate exterior body 31 Fusion and overlapping areas 100 Electrical Connection 200 rolls 300 Heat and pressure

Claims

1. A current collecting terminal for a laminated battery, comprising: the laminate battery has a laminate exterior body and an electrode stack housed in the laminate exterior body, The current collecting terminal is a current collector connection portion for electrically connecting to a current collector of the electrode laminate; an external terminal connection portion for electrically connecting to an external terminal; and a fusion portion between the current collector connection portion and the external terminal connection portion for fusion bonding to the laminate exterior body; and The fusion portion is at least partially covered with an anodic oxide coating. Current collector terminal.

2. an electrode stack; The current collecting terminal according to claim 1 , and It has a laminate exterior body, the current collector connection portion of the current collector terminal is electrically connected to the current collector of the electrode stack, the laminate exterior body is fused to the fusion portion of the current collector terminal such that the external terminal connection portion is exposed to the outside of the laminate exterior body and the current collector connection portion of the current collector terminal and the electrode stack are sealed, the fusion material constituting the laminate exterior body penetrates into the pores of the anodized coating of the current collecting terminal; Laminated battery.

3. 3. The laminate battery according to claim 2, wherein the adhesive material is an acid-modified polypropylene.

4. A method for manufacturing a laminate battery, comprising: Providing the current collecting terminal according to claim 1 or 2, electrically connecting the current collector connection portion of the current collector terminal to the current collector of the electrode stack; the current collector connection portion and the fused portion of the current collector terminal, and the electrode stack are housed inside the laminate exterior body; applying pressure to a portion of the laminate exterior body that overlaps with the fused portion while heating, so that the fusion material constituting the laminate exterior body penetrates into the pores of the anodized coating, thereby fusing the laminate exterior body and the fused portion, thereby sealing the current collector connection portion of the current collector terminal and the electrode stack; A method comprising:

5. 5. The method according to claim 4, wherein the heating temperature is 200° C. to 300° C., and the pressing pressure is 30 MPa to 100 MPa.

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