Inspection method for battery

Abstract

To provide an inspection method for a battery capable of detecting short-circuiting between a metal layer of a laminate film and a collector terminal even after an electrode laminate is sealed by the laminate film.SOLUTION: In a method for inspecting a battery, a battery 1 comprises an electrode laminate 10, a collector terminal 20 electrically connected to a collector foil of the electrode laminate, and a laminate film 30 sealing the electrode laminate. The laminate film includes a fusion resin layer, a metal layer and a protection resin layer. The method for inspecting the battery includes: bringing a first inspection terminal 100 into contact with the metal layer by piercing an extension part 30a of the laminate film therewith; bringing a second inspection terminal 200 into contact with the collector terminal; and evaluating the presence / absence of short-circuiting between the metal layer and the collector terminal.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a method for inspecting a battery. [Background technology]

[0002] A laminate battery is known in which an electrode laminate and a current collector terminal electrically connected to the current collector foil of the electrode laminate are sealed with a laminate film. In such a battery, a short circuit may occur between the metal layer in the laminate film and the current collector terminal. Therefore, a battery inspection method for detecting such a short circuit has been developed.

[0003] For example, Patent Document 1 discloses a method for inspecting a battery having an electrode laminate in which a positive electrode, a separator, and a negative electrode are laminated, a positive electrode terminal connected to the positive electrode, a negative electrode terminal connected to the negative electrode, and an exterior body that includes a metal layer and a resin layer arranged inside the metal layer, and that houses and seals the electrode laminate and an electrolyte with one end of the positive electrode terminal and the negative electrode terminal protruding to the outside, the method including a step of determining a withstand voltage between at least one of the positive electrode terminal and the negative electrode terminal and the metal layer while the electrode laminate is housed in the exterior body and the electrolyte is not injected.

[0004] That is, in Patent Document 1, one side of the laminate film needs to be left unbonded during inspection in order to be used as an inlet for the electrolyte. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2013-073900 A Summary of the Invention [Problem to be solved by the invention]

[0006] As a method for detecting a short circuit between a metal layer of a laminate film and a current collecting terminal, a method is desired that can inspect for a short circuit even after the entire periphery of the laminate film is joined and the electrode stack is sealed with the laminate film.

[0007] The present disclosure aims to provide a battery inspection method capable of detecting a short circuit between a metal layer of a laminate film and a current collecting terminal even after an electrode stack has been sealed with a laminate film. [Means for solving the problem]

[0008] The present inventors have found that the above problems can be solved by the following means. <Aspect 1> A method for inspecting a battery, comprising the steps of: the battery includes an electrode stack, a current collecting terminal electrically connected to a current collecting foil of the electrode stack, and a laminate film sealing the electrode stack; The laminate film has a fusion resin layer, a metal layer, and a protective resin layer, The method further comprising: a first inspection terminal is inserted into the extending portion of the laminate film to contact the metal layer; contacting a second inspection terminal with the current collecting terminal; and Evaluating the presence or absence of a short circuit between the metal layer and the current collecting terminal; A method for inspecting a battery, comprising: <Aspect 2> The method according to aspect 1, wherein the extension portion is formed by a fused end portion formed by fusing the fusion resin layers at the ends of the laminate film together. <Aspect 3> bending the extension portion toward the electrode stack; Inserting a receiving member between the folded extension portion and another portion of the laminate film; and piercing the first inspection terminal into the extending portion at the position where the receiving member is inserted, and contacting the first inspection terminal with the metal layer; 2. The method of embodiment 1, comprising: <Aspect 4> 4. The method of claim 3, wherein the receiving member is an adhesive member for fixing the extension portion to another portion of the laminate film. Effect of the Invention

[0009] According to the method of the present disclosure, even after the electrode stack has been sealed with a laminate film, a short circuit between the metal layer of the laminate film and the current collecting terminal can be detected. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram showing an example of a battery inspection method according to the present disclosure. [Diagram 2] FIG. 2 is a schematic cross-sectional view showing an example of a battery inspection method according to the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[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 present disclosure.

[0012] <Battery inspection method> In the disclosed method for inspecting a battery, the battery includes an electrode laminate, a current collecting terminal electrically connected to a current collecting foil of the electrode laminate, and a laminate film sealing the electrode laminate, the laminate film having a fusion resin layer, a metal layer, and a protective resin layer. The disclosed method for inspecting a battery includes piercing a first inspection terminal into an extended portion of the laminate film to contact the metal layer, contacting a second inspection terminal with the current collecting terminal, and evaluating the presence or absence of a short circuit between the metal layer and the current collecting terminal.

[0013] Hereinafter, the battery inspection method of the present disclosure will be described with reference to the drawings. Note that the dimensional relationships (length, width, thickness, etc.) in the drawings of the present disclosure do not reflect the actual dimensional relationships.

[0014] Fig. 1 is a schematic diagram showing an example of a battery inspection method of the present disclosure. In Fig. 1, a battery 1 is shown in a schematic plan view seen from the stacking direction of an electrode laminate 10. As shown in Fig. 1, in the method of the present disclosure for inspecting a battery 1, the battery 1 includes the electrode laminate 10, a current collecting terminal 20 electrically connected to a current collecting foil of the electrode laminate 10, and a laminate film 30 sealing the electrode laminate 10.

[0015] The electrode laminate 10 functions as a power generating element of the battery 1. The electrode laminate 10 may have, in this order, a negative electrode current collector, a negative electrode active material layer, an electrolyte layer, a positive electrode active material layer, and a positive electrode current collector. The shape of the electrode laminate 10 is not particularly limited, but may have, for example, a top surface portion, a bottom surface portion opposite the top surface portion, and four side surface portions connecting the top surface portion and the bottom surface portion.

[0016] The current collecting terminal 20 is electrically connected to the current collecting foil. The material of the current collecting terminal 20 is not particularly limited as long as it has a current collecting function, and may be, for example, the same metal material as the positive electrode current collector and the negative electrode current collector. The size, shape, etc. of the current collecting terminal are not particularly limited.

[0017] The laminate film 30 seals the electrode laminate 10. The laminate film 30 may be bonded around its entire periphery to seal the electrode laminate 10. The laminate film 30 may seal the electrode laminate 10 together with the current collector terminal 20. Specifically, the laminate film 30 may be formed by winding the electrode laminate 10 and the current collector terminal 20 to seal the electrode laminate 10 together with the current collector terminal 20. The laminate film 30 may be composed of a first film and a second film. In this case, the first film and the second film may sandwich the electrode laminate 10 and the current collector terminal 20 from above and below in the stacking direction of the electrode laminate 10 to seal the electrode laminate 10 together with the current collector terminal 20.

[0018] The laminate film 30 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.

[0019] The method of the present disclosure includes piercing the first inspection terminal 100 into the extending portion 30a of the laminate film 30 to contact the metal layer. Specifically, the first inspection terminal 100 is pierced into the extending portion 30a of the laminate film 30 to penetrate the protective resin layer in the extending portion 30a of the laminate film 30, thereby allowing the first inspection terminal 100 to contact the metal layer.

[0020] The method of the present disclosure includes contacting the second inspection terminal 200 with the current collecting terminal 20. Specifically, the second inspection terminal 200 can be contacted with a portion of the current collecting terminal 20 that is exposed to the outside of the laminate film 30.

[0021] The method of the present disclosure includes evaluating the presence or absence of a short circuit between the metal layer and the current collecting terminal 20. For this evaluation, a first inspection terminal 100 and a second inspection terminal 200, and a device connected to each of these inspection terminals and capable of evaluating electrical characteristics can be used. Specifically, for example, a method is exemplified in which the insulation resistance between the metal layer and the current collecting terminal 20 is measured when a predetermined voltage is applied to the first inspection terminal 100 and the second inspection terminal 200, and when the insulation resistance is smaller than a predetermined reference value, it is determined that a short circuit has occurred between the metal layer and the current collecting terminal 20. In addition, a method is exemplified in which the withstand voltage between the metal layer and the current collecting terminal 20 is measured when a predetermined voltage is applied to the first inspection terminal 100 and the second inspection terminal 200, and when insulation breakdown occurs, it is determined that a short circuit has occurred between the metal layer and the current collecting terminal 20.

[0022] Although FIG. 1 shows an embodiment for evaluating the presence or absence of a short circuit between the metal layer and the negative electrode collector terminal 20b, the evaluation for the presence or absence of a short circuit between the metal layer and the collector terminal 20 can be performed between the metal layer and either the positive electrode collector terminal 20a or the negative electrode collector terminal 20b.

[0023] The first inspection terminal 100 and the second inspection terminal 200 may each be a probe, and in particular, the first inspection terminal 100 may be a needle-shaped probe so that it can be pierced into the extension portion 30a of the laminate film 30.

[0024] The "extending portion" refers to a portion of the laminate film 30 that extends to the periphery of the electrode stack 10. The extending portion 30a may be formed by a fused end portion where the fusion resin layers at the ends of the laminate film 30 are fused to each other.

[0025] FIG. 2 is a schematic cross-sectional view showing an example of the inspection method of the present disclosure when the battery 1 is viewed from the side of the current collector terminal 20. As shown in FIG. 2, the method of the present disclosure may include folding the extension portion 30a toward the electrode laminate 10, inserting the receiving member 300 between the folded extension portion 30a and another portion of the laminate film 30, and piercing the first inspection terminal 100 into the extension portion 30a at the position where the receiving member 300 is inserted, so as to contact the metal layer. According to such a method, it is easy to pierce the first inspection terminal 100 into the extension portion 30a. In addition, for example, by penetrating the first inspection terminal 100 into the receiving member 300 through the extension portion 30a, the first inspection terminal 100 is held by the receiving member 300, and as a result, it is easy to avoid the first inspection terminal 100 coming into contact with components other than the component to be inspected.

[0026] The receiving member 300 in the method of the present disclosure is not particularly limited, but may have a hardness to the extent that the first inspection terminal 100 can be pierced, for example. The receiving member 300 may be an adhesive member for fixing the extension portion 30a to another portion of the laminate film 30. By using the receiving member 300 as an adhesive member, the extension portion 30a of the laminate film 30 can be kept fixed to another portion of the laminate film 30 in the battery 1 after inspection, and as a result, the battery 1 can have high volume efficiency. Examples of the adhesive member include, but are not limited to, an adhesive resin. The other portion of the laminate film 30 may be a portion of the laminate film 30 that is in contact with the side portion of the electrode laminate 10 on the side where the extension portion 30a is formed.

[0027] The battery tested by the method of the present disclosure may be a liquid battery or a solid-state battery. Note that, 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 thus 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 inspected by the method of the present disclosure may be 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 automobiles, and diesel 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 moving objects other than vehicles (e.g., railways, ships, and aircraft), and may also be used as a power source for electrical products such as information processing devices. [Explanation of symbols]

[0029] 1 battery 10 Electrode laminate 20 Current collector terminal 30 Laminating Film 30a Extension 100 First inspection terminal 200 Second inspection terminal 300 Receiving member

Claims

1. A method for inspecting a battery, comprising the steps of: the battery includes an electrode stack, a current collecting terminal electrically connected to a current collecting foil of the electrode stack, and a laminate film sealing the electrode stack; The laminate film has a fusion resin layer, a metal layer, and a protective resin layer, The method further comprising: a first inspection terminal is inserted into the extending portion of the laminate film to contact the metal layer; contacting a second inspection terminal with the current collecting terminal; and Evaluating the presence or absence of a short circuit between the metal layer and the current collecting terminal; A method for inspecting a battery, comprising:

2. The method according to claim 1 , wherein the extension portion is formed by a fused end portion formed by fusion-bonding fusion resin layers at the ends of the laminate film.

3. bending the extension portion toward the electrode stack; Inserting a receiving member between the folded extension portion and another portion of the laminate film; and the first inspection terminal is inserted into the extending portion at the position where the receiving member is inserted, and brought into contact with the metal layer; The method of claim 1 , comprising:

4. The method according to claim 3 , wherein the receiving member is an adhesive member for fixing the extension portion to another portion of the laminate film.

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