Battery current collection terminals and batteries

Abstract

To provide a collector terminal for a battery which can secure the electronic conduction and also can suppress heat transfer to an electrode laminate body and a sealing part of a laminate film when the power terminal is joined to an external connection terminal, and a battery having the collector terminal.SOLUTION: A collector terminal 10 for a battery includes: a collector foil joint unit 11 for joining a collector foil of an electrode multilayer body; a peripheral part 12 for fusing a laminate film; and an external connection terminal joint part 13 for joining to an external connection terminal; and a low-heat conduction region 14 between the peripheral part 12 and the external connection terminal 13. A battery 1 of the present disclosure includes: an electrode multilayer body 20; the collector terminal 10 of the present disclosure electrically connected to the collector foil of the electrode laminate body; and a laminate film 30 for sealing the collector terminal and the electrode multilayer body.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a current collecting terminal for a battery and a battery.

Background Art

[0002] A laminated battery (also referred to as a pouch battery) in which an electrode laminate is sealed with a laminated film is known.

[0003] For example, Patent Document 1 discloses a secondary battery comprising: an electrode laminate obtained by laminating sheet-shaped electrode elements; and an exterior body that accommodates the electrode laminate therein, the exterior body having a cylindrical laminated film exterior body that covers at least both end faces in the lamination direction of the electrode laminate and a pair of opposing side surfaces, and an inner lid disposed at an opening of the laminated film exterior body, wherein the electrode laminate is sealed inside the exterior body by joining an outer peripheral portion of the inner lid and the laminated film exterior body overlapping the outer peripheral portion of the inner lid.

[0004] Patent Document 1 also discloses that the outer peripheral portion of the inner lid and the laminated film exterior body can be joined by heat welding (fusion bonding).

Prior Art Literature

Patent Literature

[0005]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0006] In laminated batteries, there are known batteries in which the current collector terminal itself is shaped like the inner lid described in Patent Document 1, that is, shaped to have a predetermined volume, thereby sealing the electrode laminate together with the laminate film. In batteries having such a current collector terminal, when an external connection terminal is joined to the current collector terminal in order to form a battery module, heat generated during joining may transfer from the current collector terminal to the electrode laminate. As a result, the performance of the battery is impaired.

[0007] Furthermore, the heat mentioned above can transfer to the sealing portion of the laminate film where the current collection terminal and the laminate film are fused together, potentially causing manufacturing defects such as poor sealing.

[0008] On the other hand, in order to avoid impairing the battery's performance, it is necessary to ensure electronic conductivity at the current collection terminals.

[0009] The present disclosure aims to provide a battery current collector terminal that can suppress heat transfer to the electrode laminate and the sealing portion of the laminate film when joined to an external connection terminal, while ensuring electronic conductivity, and a battery having such a current collector terminal. [Means for solving the problem]

[0010] The Disclosing Party has found that the above-mentioned problems can be solved by the following means. <Aspect 1> Current collector foil joining section for joining current collector foils of electrode laminates, Peripheral portion for fusing the laminate film, and It has an external connection terminal connection part for connecting to an external connection terminal, A low thermal conductivity region is provided between the peripheral portion and the external connection terminal joint portion. Battery current collection terminal. <Aspect 2> The current collector terminal according to embodiment 1, wherein the low thermal conductivity region is formed by a through hole. <Aspect 3> The current collector terminal according to embodiment 2, wherein the low thermal conductivity region is formed by filling the through hole with a material that has lower thermal conductivity than the other parts of the current collector terminal. <Aspect 4> Electrode stack, A current collector terminal according to any one of embodiments 1 to 3, which is electrically connected to the current collector foil of the electrode laminate, and The laminate film that seals the electrode laminate together with the current collection terminal. A battery containing a battery. [Effects of the Invention]

[0011] According to this disclosure, it is possible to provide a current collector terminal for a battery that can ensure electronic conductivity while suppressing heat transfer to the electrode laminate and the sealing portion of the laminate film when joined to an external connection terminal, and a battery having such a current collector terminal. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1 is a schematic perspective view showing an example of a current collector terminal of this disclosure. [Figure 2] Figure 2 is a schematic plan view showing an example of a current collector terminal of the present disclosure. [Figure 3] Figure 3 is a schematic plan view showing an example of a current collector terminal of the present disclosure. [Figure 4] Figure 4 is a schematic plan view showing an example of a current collector terminal of the present disclosure. [Figure 5] Figure 5 is a schematic plan view showing an example of the battery of this disclosure. [Modes for carrying out the invention]

[0013] The embodiments of this disclosure will be described in detail below. However, this disclosure is not limited to the embodiments described below, and can be implemented in various modified forms within the scope of the essence of the disclosure.

[0014] Hereinafter, the current collecting terminal for a battery and the battery of the present disclosure will be described with reference to the drawings. Note that the dimensional relationships in the drawings do not reflect actual dimensional relationships.

[0015] <<Current Collecting Terminal for Battery>> As illustrated in FIG. 1, the current collecting terminal 10 for a battery of the present disclosure includes a current collector foil joining portion 11 for joining a current collector foil of an electrode laminate 20, a peripheral edge portion 12 for fusing a laminate film, and an external connection terminal joining portion 13 for joining to an external connection terminal, and has a low thermal conductivity region 14 between the peripheral edge portion 12 and the external connection terminal joining portion 13.

[0016] As described above, when joining an external connection terminal to a current collecting terminal to form a battery module, heat generated during joining may transfer from the current collecting terminal to the electrode laminate and the sealing portion of the laminate film where the current collecting terminal and the laminate film are fused together.

[0017] In this regard, the present disclosers and others have found that by providing a low thermal conductivity region in the current collecting terminal, the thermal conductivity of the current collecting terminal can be reduced, thereby suppressing heat transfer from the current collecting terminal to the electrode laminate and the sealing portion of the laminate film when joining the external connection terminal to the current collecting terminal.

[0018] As illustrated in FIG. 1, the shape of the current collecting terminal 10 for a battery of the present disclosure may be, for example, a rectangular parallelepiped having a top surface portion, a bottom surface portion facing the top surface portion, and four side surface portions connecting the top surface portion and the bottom surface portion. In this case, the low thermal conductivity region 14 may be, for example, a region formed to communicate between the top surface portion and the bottom surface portion. The current collector foil joining portion 11 may be any one of the four side surface portions. The external connection terminal joining portion 13 may be a side surface portion of the four side surface portions that faces the side surface portion serving as the current collector foil joining portion 11. The peripheral edge portion 12 may be a portion formed from a portion between the low thermal conductivity region 14 and the side surface portion serving as the current collector foil joining portion 11 in the top surface portion and the bottom surface portion, and a side surface portion that is neither the current collector foil joining portion 11 nor the external connection terminal joining portion 13.

[0019] The shape of the current collection terminal is not limited to a rectangular parallelepiped. For example, the shape of the top surface of the current collection terminal can be a quadrilateral such as a square, rectangle, rhombus, trapezoid, or parallelogram. The shape of the top surface may also be a polygon other than a quadrilateral, or a curved shape such as a circle. The shape of the bottom surface may be the same as the shape of the top surface. The shape of the side surface is not particularly limited, but examples include a quadrilateral such as a square, rectangle, rhombus, trapezoid, or parallelogram.

[0020] The low thermal conductivity region 14 may be formed by through holes. With such a configuration, the thermal conductivity of the current collector terminal can be made particularly low, and the effect of suppressing heat transfer from the current collector terminal to the sealing portion of the electrode laminate and laminate film can be easily achieved. In addition, by reducing the weight of the current collector terminal, it is possible to contribute to the weight reduction of the battery.

[0021] The low thermal conductivity region 14 may be formed by filling the through-hole with a material that has lower thermal conductivity than the rest of the current collector terminal. With such a configuration, the thermal conductivity of the current collector terminal can be reduced while maintaining the strength of the current collector terminal.

[0022] With regard to this disclosure, the material of the current collector terminal is not particularly limited as long as it is a material that has a current collecting function, and for example, it can be the same metallic material as the positive electrode current collector and the negative electrode current collector that constitute the electrode laminate. Specifically, examples of materials for the current collector terminal include metallic materials such as aluminum.

[0023] If the material of the current collector terminal other than the heat conduction region is metal, the material constituting the low heat conduction region is not particularly limited, but examples include resin.

[0024] The volume of the low thermal conductivity region is not particularly limited and can be appropriately designed depending on the volume of the current collector terminal and the amount of heat generated when joining the external connection terminal to the current collector terminal.

[0025] In Figures 1 and 2, the low-thermal-conductivity region is shown as a rectangular parallelepiped, but the shape of the low-thermal-conductivity region is not particularly limited. Examples of planar shapes of the low-thermal-conductivity region include quadrilaterals such as squares, rectangles, rhombuses, trapezoids, and parallelograms. Furthermore, the planar shape of the low-thermal-conductivity region may be a polygon other than a quadrilateral, or a shape with curves such as a circle (see Figure 3).

[0026] The number of low thermal conductivity regions is not particularly limited and may be one or more (see Figure 3).

[0027] As illustrated in Figure 4, the low thermal conductivity region may be formed such that its edges are in contact with the side surface of the current collector terminal. In other words, a portion of the side surface of the current collector terminal may be missing in order to form the low thermal conductivity region.

[0028] There are no particular limitations on the method for manufacturing current collector terminals having through holes as low thermal conductivity regions, but examples include punching them out using a press and a drill to achieve a desired shape, size, etc.

[0029] The above describes an embodiment in which the low thermal conductivity region is formed by through holes and extends in the stacking direction of the electrode stack. However, the direction in which the low thermal conductivity region extends is not particularly limited, and for example, it may be formed to extend in the plane direction of the electrode stack.

[0030] "battery" As illustrated in Figure 5, the battery 1 of the present disclosure includes an electrode stack 20, a current collector terminal 10 of the present disclosure which is electrically connected to the current collector foil of the electrode stack, and a laminate film 30 which seals the electrode stack together with the current collector terminal.

[0031] The battery in this disclosure may be a liquid-based battery or a solid-state battery. In this disclosure, "solid-state battery" means a battery that uses at least a solid electrolyte as its electrolyte, and therefore a solid-state battery may use a combination of a solid electrolyte and a liquid electrolyte as its electrolyte. Furthermore, the solid-state battery in this disclosure may be an all-solid-state battery, i.e., a battery that uses only a solid electrolyte as its electrolyte.

[0032] The battery in this disclosure may be, for example, a lithium-ion secondary battery. Applications of the battery include, for example, powering vehicles such as hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), battery electric vehicles (BEVs), gasoline-powered vehicles, and diesel-powered vehicles. It is particularly preferable that the battery be used as a power source for hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), or electric vehicles (BEVs). Furthermore, the battery in this disclosure may be used as a power source for mobile devices other than vehicles (e.g., railways, ships, aircraft), or as a power source for electrical products such as information processing devices.

[0033] <Electrode Laminate> The electrode stack 20 functions as a power generation element of the battery. The shape of the electrode stack is not particularly limited, but 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, but may 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 a curved shape such as a circle. The shape of the bottom surface is the same as the shape of the top surface. The shape of the side surfaces is not particularly limited, but may include quadrilaterals such as squares, rectangles, rhombuses, trapezoids, and parallelograms.

[0034] 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. The materials constituting each layer can be those commonly used in the field of batteries.

[0035] <Laminating film> The laminate film 30 seals the electrode laminate 20 together with the current collector terminal 10. Specifically, the laminate film may be wound around the electrode laminate and the current collector terminal to seal the electrode laminate together with the current collector terminal. Alternatively, the laminate film may be composed of a first and a second film, in which case the first and second films may sandwich the electrode laminate and the current collector terminal from above and below in the stacking direction of the electrode laminate to seal the electrode laminate together with the current collector terminal.

[0036] The laminate film may have a fusion resin layer, a metal layer, and a protective resin layer in this order along the thickness direction. Examples of materials for the fusion resin layer include olefin resins such as polypropylene (PP) and polyethylene (PE). 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 to 100 μm. The thickness of the metal layer may be, for example, 30 μm to 60 μm. The thickness of the protective resin layer may be, for example, 20 μm to 60 μm. The thickness of the laminate film may be, for example, 80 μm to 250 μm.

[0037] <Collector terminal> For current collection terminals, refer to the above description regarding current collection terminals for batteries in this disclosure. [Explanation of Symbols]

[0038] 1 battery 10 Battery current collection terminals 11 Current collector foil joint 12 Peripheral area 13 External connection terminal joint 14 Low thermal conductivity region 20 Electrode Stack 30 Laminating Films

Claims

1. Current collector foil joining section for joining current collector foils of electrode laminates, Peripheral portion for fusing the laminate film, and It has an external connection terminal connection part for connecting to an external connection terminal, A low thermal conductivity region is provided between the peripheral portion and the external connection terminal joint portion. Battery current collection terminal.

2. The current collector terminal according to claim 1, wherein the low thermal conductivity region is formed by a through hole.

3. The current collector terminal according to claim 2, wherein the low thermal conductivity region is formed by filling the through hole with a material that has lower thermal conductivity than the other parts of the current collector terminal.

4. Electrode stack, A current collector terminal according to any one of claims 1 to 3, which is electrically connected to the current collector foil of the electrode laminate, and The laminate film that seals the electrode laminate together with the current collection terminal. A battery containing a battery.

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