Battery manufacturing method, battery, manufacturing method for laminate film with edge insulating member, and laminate film with edge insulating member

Abstract

To provide a method for manufacturing a battery that allows for easy placement of an insulating member on the edge of a laminate film.SOLUTION: A disclosed method for manufacturing a battery 10 includes the steps of (a) providing an electrode stack 110 housed in a laminate film 120, (b) at least partially joining the laminate films to each other around the periphery of the electrode stack to form a peripheral joint 120a, and (c) disposing an insulating member 130 so as to cover an edge surface 120b of the laminate film and at least a portion of a major surface 120c of the laminate film adjacent to the edge surface.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a method for manufacturing a battery, a battery, a method for manufacturing a laminate film with end insulating members, and a laminate film with end insulating members. [Background technology]

[0002] Batteries including an electrode stack and a laminate film housing the electrode stack are known. In such batteries, the edges of the components constituting the laminate film may need to be protected. For example, if the laminate film has a metal layer, the exposed metal layer may be exposed to moisture, air, and the like, which can cause the battery to deteriorate. Therefore, a technique has been developed in which an insulating member is disposed at the edge of the laminate film to protect the metal layer.

[0003] For example, Patent Document 1 discloses a pouch-type secondary battery that includes a battery case made of a laminate sheet (laminate film) and an electrode assembly (electrode laminate) housed in the battery case, the battery case consisting of an upper case and a lower case made of a laminate sheet including an outer coating layer (protective resin layer), a metal layer, and an inner coating layer (sealant resin layer), sealing parts for joining the upper case and the lower case to each other are provided on the outer peripheral edges of the upper case and the lower case, and a conformal coating layer (insulating member) is formed on the side of the sealing part to prevent exposure of the metal layer. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2021-510901 Summary of the Invention [Problem to be solved by the invention]

[0005] In terms of productivity, there is room for improvement in the process of disposing the insulating member on the laminate film.

[0006] The present disclosure aims to provide a method for manufacturing a battery that allows for easy placement of insulating members on the edges of a laminate film, and a battery that can be manufactured by such a method. The present disclosure also aims to provide a method for manufacturing a laminate film with edge insulating members that allows for easy placement of insulating members on the edges, and a laminate film with edge insulating members that can be manufactured by such a manufacturing method. [Means for solving the problem]

[0007] The present inventors have found that the above problems can be solved by the following means. <Aspect 1> A method for manufacturing a battery, comprising the steps of: (a) providing an electrode stack encased in a laminate film; (b) at least partially joining the laminate films to each other around the periphery of the electrode stack to form a peripheral joint; (c) The insulating member is arranged so as to cover the end surface of the laminate film and at least a part of the main surface of the laminate film adjacent to the end surface. <Aspect 2> 2. The method of claim 1, wherein in step (b), a peripheral bond is formed on an edge surface of the laminate film. <Aspect 3> The method according to embodiment 1, wherein in step (b), a peripheral bond is formed on a portion other than the edge surface of the laminate film. <Aspect 4> 4. The method according to claim 3, wherein in step (c), the insulating member is disposed so as to be inserted between the laminate films. <Aspect 5> Aspect 5. The method according to any one of aspects 1 to 4, further comprising, after step (b), cutting the edges of the laminate film. <Aspect 6> A battery comprising an electrode stack and a laminate film housing the electrode stack, the laminate film has a peripheral joint portion at which the laminate film is at least partially joined to each other at a peripheral edge of the electrode stack; an insulating member is disposed so as to cover an end surface of the laminate film and at least a part of a main surface of the laminate film adjacent to the end surface; battery. <Aspect 7> 7. The battery of claim 6, wherein the laminate film has a sealant resin layer, a metal layer, and a protective resin layer in this order. <Aspect 8> 8. The battery of claim 6 or 7, wherein the laminate films are bonded to each other at the end surfaces. <Aspect 9> Aspect 8. The battery of aspect 6 or 7, wherein the laminate films are not bonded to each other at the end surfaces. <Aspect 10> 10. The battery of claim 9, wherein the insulating member is interposed between the laminate films at the end surfaces. <Aspect 11> A method for manufacturing a laminate film with an insulating edge member, comprising the steps of: The insulating member is arranged so as to cover the end surface of the laminate film and at least a part of the main surface of the laminate film adjacent to the end surface. <Aspect 12> A laminated film with end insulating members, wherein an insulating member is arranged to cover an end surface and at least a portion of a main surface adjacent to the end surface. <Aspect 13> an electrode stack, and The laminate film with end insulators according to aspect 12, which houses the electrode stack. A battery comprising: [Effects of the Invention]

[0008] The method of the present disclosure makes it possible to easily manufacture a battery of the present disclosure in which insulating members are arranged on the edges of a laminate film, and also to easily manufacture a laminate film with edge insulating members in which insulating members are arranged on the edges. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram illustrating the disclosed method of manufacturing a battery. [Figure 2] FIG. 2 is a schematic perspective view showing an example of a battery according to the present disclosure. [Figure 3] FIG. 3 is a schematic plan view showing an example of a battery according to the present disclosure. [Figure 4] FIG. 4 is a schematic cross-sectional view showing an example of an arrangement of insulating members in the battery of the present disclosure. [Figure 5] FIG. 5 is a schematic cross-sectional view showing an example of an arrangement of insulating members in the battery of the present disclosure. [Figure 6] FIG. 6 is a schematic cross-sectional view showing an example of the arrangement of insulating members in a laminate film with end insulating members of the present disclosure. [Figure 7] FIG. 7 is a schematic cross-sectional view showing an example of the arrangement of insulating members in a battery including a laminate film with end insulating members of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. 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. Furthermore, the dimensional relationships in the drawings do not reflect the actual dimensional relationships.

[0011] <Battery manufacturing method> As illustrated in FIG. 1 and FIGS. 4 and 5, the disclosed method for manufacturing battery 10 includes the following steps: (a) preparing an electrode stack 110 housed in a laminate film 120; (b) at least partially joining the laminate films to each other around the periphery of the electrode stack to form a peripheral joint 120a; and (c) disposing an insulating member 130 so as to cover an end surface 120b of the laminate film and at least a portion of a major surface 120c of the laminate film adjacent to the end surface.

[0012] The present inventors have discovered that, according to this method, after encasing the electrode stack in a laminate film, it is only necessary to place an insulating member on the end face of the laminate film present on the periphery of the electrode stack and on at least a portion of the main surface adjacent to the end face, and therefore it is possible to easily manufacture a battery in which an insulating member is placed on the laminate film.

[0013] In a battery including an electrode stack and a laminate film housing the electrode stack, it is desirable that the insulating member disposed on the edge of the laminate film is not easily peeled off from the laminate film.

[0014] In this regard, the present inventors have discovered that in a laminate film having a peripheral joint where the electrodes are at least partially joined to each other around the periphery of the electrode stack, the insulating member is arranged so as to cover the edge of the laminate film and at least a portion of the main surface of the laminate film adjacent to the edge, making the insulating member less likely to peel off from the laminate film. This is thought to be because, when the insulating member is arranged so as to cover the edge of the laminate film as described above, the contact area between the laminate film and the insulating member increases and the resistance to external forces from directions other than those toward the insulating member from the electrode stack side of the battery is strengthened.

[0015] Each step of the disclosed method for manufacturing a battery is described below.

[0016] <Electrode Stack Preparation Step> As illustrated in FIG. 1(a), the method of the present disclosure includes (a) preparing an electrode stack 110 housed in a laminate film 120. The method for housing the electrode stack in the laminate film is not particularly limited. For example, as illustrated in FIG. 1(a), a method of housing the electrode stack by wrapping it in a laminate film may be used. Alternatively, for example, a laminate film composed of first and second films may be used, and the electrode stack may be housed by being sandwiched between the first and second films from above and below in the stacking direction of the electrode stack.

[0017] <Peripheral joint forming process> 1(b), the method of the present disclosure includes (b) at least partially joining the laminate films to each other around the periphery of the electrode laminate to form a peripheral joint 120a. The method for forming the peripheral joint is not particularly limited, and for example, when the laminate film has a sealant resin layer, a method of welding the sealant resin layer to each other can be exemplified.

[0018] In the method of the present disclosure, a peripheral bonded portion may be formed on the edge surface of the laminate film, or on a portion other than the edge surface of the laminate film. That is, the laminate films may or may not be bonded to each other at the edge surface.

[0019] The method of the present disclosure may include a step of cutting the edge of the laminate film after step (b). The cutting position may be, for example, the position indicated by the dashed line in FIG. 1(b). In this case, in step (c) described below, an insulating member may be placed on the edge of the laminate film so as to cover the cut surface thus formed. A laminate film previously cut to a size capable of accommodating the electrode stack may be used, and an insulating member may be placed on the cut surface so as to cover the cut surface.

[0020] <Insulating member placement process> 1(c) and 4 and 5, the method of the present disclosure includes (c) disposing an insulating member 130 so as to cover an end surface 120b of the laminate film and at least a portion of a main surface 120c of the laminate film adjacent to the end surface. Note that Fig. 1(c) is a schematic diagram illustrating, in a side view perpendicular to the winding direction of the laminate film, how the laminate film is immersed in the insulating member as an example of a method for disposing the insulating member on the laminate film.

[0021] As illustrated in Fig. 5, in step (c), the insulating member 130 may be disposed so as to penetrate between the laminate films 120. By using such a method, the insulating member is less likely to peel off from the laminate film. When the laminate film has a sealant resin layer 121, the insulating member 130 may be disposed so as to penetrate between the opposing sealant resin layers 121, as illustrated in Fig. 5.

[0022] The method for disposing the insulating member is not particularly limited. For example, when the insulating member is a thermoplastic resin, examples include a method of immersing the end face of the laminate film and at least a part of the main surface of the laminate film adjacent to the end face in molten thermoplastic resin, and a method of applying molten thermoplastic resin to the end face of the laminate film and at least a part of the main surface of the laminate film adjacent to the end face.

[0023] For example, when the insulating member is a curable resin, examples include a method of immersing the end face of the laminate film and at least a portion of the main surface of the laminate film adjacent to the end face in the curable resin and curing it, and a method of applying the curable resin to the end face of the laminate film and at least a portion of the main surface of the laminate film adjacent to the end face and curing it.

[0024] When the insulating member is one of these resins, from the viewpoint of productivity and from the viewpoint of easily inserting the insulating member between the laminate films when the laminate films are not joined to each other at their end faces, a method can be adopted in which the end faces of the laminate film and at least a portion of the main surface of the laminate film adjacent to the end faces are immersed in one of these resins, as illustrated in Figure 1(c).

[0025] "battery" As illustrated in Fig. 3, the battery 10 of the present disclosure includes an electrode stack 110 and a laminate film 120 that houses the electrode stack 110. As illustrated in Figs. 2 to 5, in the battery 10 of the present disclosure, the laminate film 120 has a peripheral joint portion 120a where the laminate films 120 are at least partially joined to each other around the periphery of the electrode stack 110, and an insulating member 130 is disposed so as to cover an end face 120b of the laminate film 120 and at least a portion of a main surface 120c of the laminate film 120 adjacent to the end face 120b.

[0026] Such a battery is easy to manufacture, and the insulating member is less likely to peel off from the laminate film.

[0027] The battery may be a lithium-ion secondary battery. Examples of uses for 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.

[0028] The elements that make up the battery of the present disclosure will be described below.

[0029] <Electrode laminate> 3, the battery 10 of the present disclosure includes an electrode stack 110. The electrode stack 110 functions as the power generating element of the battery.

[0030] 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 polygonal other than a quadrilateral, or may have 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, and examples thereof include quadrilaterals such as squares, rectangles, rhombuses, trapezoids, and parallelograms.

[0031] The electrode laminate may have a negative electrode current collector layer, a negative electrode active material layer, an electrolyte layer, a positive electrode active material layer, and a positive electrode current collector layer in this order. The material of each layer is not particularly limited, and a commonly used material for constituting each layer can be used. The thickness of the electrode laminate and each layer constituting the electrode laminate is not particularly limited.

[0032] <Laminating film> The laminate film 120 houses the electrode stack 110. Specifically, the electrode stack may be wound and housed in the laminate film. The laminate film may also be made up of first and second films, and in this case, the electrode stack may be housed by being sandwiched between the first and second films from above and below in the stacking direction of the electrode stack.

[0033] 2 to 5, in the battery 10 of the present disclosure, the laminate film 120 has a peripheral joint 120a that is at least partially joined to each other around the periphery of the electrode stack 110. That is, at least a portion of the portions of the laminate film formed by accommodating the electrode stack that are present around the periphery of the electrode stack may be joined to each other, and therefore, the portions of the laminate film that are present around the periphery of the electrode stack may have portions that are not joined to each other. Alternatively, the entire portions of the laminate film that are present around the periphery of the electrode stack may be joined to each other.

[0034] 4 and 5 are enlarged schematic cross-sectional views of an end portion of the laminate film 120 of the battery 10 of the present disclosure. As illustrated in FIGS. 4 and 5, the laminate film 120 may have a sealant resin layer 121, a metal layer 122, and a protective resin layer 123 in this order. In this case, the peripheral joint 120a may be formed by welding the sealant resin layers together.

[0035] Examples of materials for the sealant 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.

[0036] The thickness of each layer constituting the laminate film and the laminate film itself are not particularly limited. The thickness of the sealant resin layer is, for example, 40 μm or more and 100 μm or less. The thickness of the metal layer is, for example, 30 μm or more and 60 μm or less. The thickness of the protective resin layer is, for example, 20 μm or more and 60 μm or less. The thickness of the laminate film is, for example, 80 μm or more and 250 μm or less.

[0037] Insulating materials As illustrated in Figures 4 and 5, in the battery 10 of the present disclosure, the insulating member 130 is arranged to cover the end surface 120b of the laminate film 120 and at least a portion of the main surface 120c of the laminate film 120 adjacent to the end surface 120b.

[0038] When the laminate film 120 has a metal layer 122, the end surface 120b of the laminate film on which the insulating member 130 is disposed may be an end surface where the metal layer 122 is exposed. Such an end surface 120b may be, for example, a cut surface formed by cutting the end of the laminate film 120 at the periphery of the electrode stack 110.

[0039] 4, the laminate films 120 may be joined to each other at the edge surfaces 120b. That is, a peripheral joint 120a may be formed at the edge surfaces 120b. In this case, the insulating member 130 may be arranged at the peripheral joint 120a to cover the edge surfaces 120b of the laminate films 120 and at least a portion of the main surface 120c of the laminate films 120 adjacent to the edge surfaces 120b.

[0040] As illustrated in FIG. 5, the laminate films 120 may not be bonded to each other at the edge surfaces 120b. That is, a peripheral bonded portion 120a may be formed in a portion other than the edge surfaces 120b. In this case, the insulating member 130 may penetrate between the laminate films 120 at the edge surfaces of the laminate films. If the laminate film has a sealant resin layer, the insulating member 130 may penetrate between the opposing sealant resin layers 121. That is, the insulating member may also be disposed between the sealant resin layers. This configuration makes the insulating member 130 even less likely to peel off from the laminate film 120.

[0041] The insulating member 130 is not particularly limited, but may be a resin such as a thermoplastic resin, a curable resin, etc. From the viewpoint of productivity, the insulating member may particularly be a thermoplastic resin.

[0042] The thermoplastic resin is not particularly limited and may be either a non-reactive type or a reactive type. Examples of non-reactive thermoplastic resins include, but are not particularly limited to, ethylene vinyl acetate (EVA)-based, synthetic rubber-based, olefin-based, polyamide-based, and polyester-based resins such as polyethylene terephthalate (PET). Examples of reactive resins include, but are not particularly limited to, urethane-based resins.

[0043] The curable resin is not particularly limited, and examples thereof include thermosetting resins and photocurable resins, such as acrylic and epoxy resins.

[0044] <Collector terminal> The battery of the present disclosure may further include a current collecting terminal 140. The current collecting terminal may be electrically connected to the current collecting portion of the electrode stack. The material of the current collecting terminal is not particularly limited as long as it has a current collecting function. As illustrated in Figures 2 and 3, the current collecting terminal may be disposed on a pair of opposing side surfaces of the electrode stack.

[0045] The shape and size of the current collecting terminal are not particularly limited.

[0046] When the battery of the present disclosure has a current collecting terminal, the laminate film may house the electrode laminate together with the current collecting terminal. Specifically, the laminate film may house the electrode laminate together with the current collecting terminal by winding the electrode laminate and the current collecting terminal. The laminate film may also be composed of first and second films. In this case, the first and second films may sandwich the electrode laminate and the current collecting terminal from above and below in the stacking direction of the electrode laminate, housing the electrode laminate together with the current collecting terminal.

[0047] <<Method for manufacturing laminate film with end insulating members>> The disclosed method for manufacturing a laminate film 220 with edge insulating members includes disposing an insulating member 230 so as to cover an edge surface 220b of the laminate film and at least a portion of a main surface 220c of the laminate film adjacent to the edge surface.

[0048] The present inventors have found that, according to this method, it is possible to easily manufacture a laminate film having insulating members disposed on the edges.

[0049] For the method of disposing the insulating member, reference can be made to the above description of the manufacturing method of the battery of the present disclosure. For example, when a method of disposing the insulating member by immersing the laminate film in the insulating member is adopted, the laminate film can be immersed in the insulating member as exemplified in FIG. 1(c).

[0050] <Laminated film with insulating edge> As illustrated in FIG. 6, in a laminate film 220 with end insulating members according to the present disclosure, an insulating member 230 is disposed so as to cover an end surface 220b and at least a portion of a main surface 220c adjacent to the end surface 220b.

[0051] The laminate film with end insulating members is easy to manufacture, and the insulating members are unlikely to peel off from the laminate film.

[0052] The laminate film 220 with end insulating members may have a sealant resin layer 221, a metal layer 222, and a protective resin layer 223 in this order.

[0053] The end faces of the laminate film with end insulating members of the present disclosure may be cut surfaces of the laminate film that can accommodate the electrode laminate, taking into consideration the size and shape of the electrode laminate, and that minimize the portion of the laminate film that will be present on the periphery of the electrode laminate.

[0054] A battery may also be provided in which an electrode stack is housed in a laminate film with edge insulation. That is, the battery 20 includes an electrode stack 210 and a laminate film with edge insulation 220 of the present disclosure that houses the electrode stack 210. The laminate film with edge insulation 220 may have a peripheral joint 220a that is at least partially joined to each other around the periphery of the electrode stack 210. For the laminate film with edge insulation 220 of the present disclosure, reference can be made to the above description of the laminate film with edge insulation of the present disclosure.

[0055] In this way, by using a laminate film with end insulating members in which insulating members are arranged in desired positions in advance, it is possible to easily manufacture a battery in which the insulating members are less likely to peel off from the laminate film, as exemplified in Figure 7. Figure 7 is a schematic cross-sectional view showing an enlarged view of an end of laminate film 220 with end insulating members of battery 20 of the present disclosure.

[0056] For the elements constituting the battery, reference can be made to the above description of the battery of the present disclosure. [Explanation of symbols]

[0057] 10, 20 batteries 110, 210 Electrode laminate 120 Laminating Film 220 Laminated film with edge insulation 120a, 220a Peripheral joint 120b, 220b end face 120c, 220c main surface 121, 221 Sealant resin layer 122, 222 metal layer 123, 223 Protective resin layer 130, 230 Insulating member 140 Current collector terminal

Claims

1. A method for manufacturing a battery, comprising the steps of: (a) providing an electrode stack housed in a laminate film; (b) at least partially joining the laminate films to each other around the periphery of the electrode stack to form a peripheral joint; (c) The insulating member is arranged so as to cover the end surface of the laminate film and at least a part of the main surface of the laminate film adjacent to the end surface.

2. The method according to claim 1 , wherein in step (b), a peripheral bond is formed on the edge surface of the laminate film.

3. The method according to claim 1 , wherein in step (b), a peripheral joint is formed on a portion other than the end surface of the laminate film.

4. The method according to claim 3 , wherein in the step (c), the insulating member is disposed so as to be inserted between the laminate films.

5. The method according to any one of claims 1 to 4, further comprising the step of cutting the edges of the laminate film after step (b).

6. A battery comprising an electrode stack and a laminate film housing the electrode stack, the laminate film has a peripheral joint portion at which the laminate film is at least partially joined to each other at a peripheral edge of the electrode stack; an insulating member is disposed so as to cover an end surface of the laminate film and at least a part of a main surface of the laminate film adjacent to the end surface; battery.

7. The battery according to claim 6 , wherein the laminate film has a sealant resin layer, a metal layer, and a protective resin layer in this order.

8. The battery according to claim 6 or 7, wherein the laminate films are joined to each other at the end faces.

9. The battery according to claim 6 or 7, wherein the laminate films are not joined to each other at the end surfaces.

10. The battery according to claim 9 , wherein the insulating member is interposed between the laminate films at the end surfaces.

11. A method for producing a laminate film with an end insulating member, comprising the following steps: The insulating member is arranged so as to cover the end surface of the laminate film and at least a part of the main surface of the laminate film adjacent to the end surface.

12. A laminated film with end insulating members, wherein an insulating member is arranged to cover an end surface and at least a portion of a main surface adjacent to the end surface.

13. an electrode stack, and The laminate film with end insulating members according to claim 12, which houses the electrode stack. A battery comprising:

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