Electrode member

Abstract

An electrode member includes a base material including a resin base material and a conductive layer formed on the resin base material, and an active material layer formed on the conductive layer. The base material has a coated region coated with the active material layer and an uncoated region uncoated with the active material layer. The resin base material is composed of a crystalline polymer. The crystallinity of the crystalline polymer located in the coated region is greater than the crystallinity of the crystalline polymer located in the uncoated region.

Description

Technical Field

[0001] This disclosure relates to electrode components. Background Technology

[0002] As a conventional electrode, Japanese Patent Application Publication No. 2019-096592 discloses a structure in which at least one of a sheet-like positive electrode member and a negative electrode member is formed by sequentially laminating a conductive layer and an active material layer on the surface of an insulating substrate, with a spacer disposed between the positive electrode member and the negative electrode member, and the two are wound together. The conductive layer includes a first portion coated with an active material layer and a second portion protruding from the first portion, and through holes extending in the thickness direction are provided in the second portion and in the portion of the insulating substrate corresponding to the second portion. Summary of the Invention

[0003] In the manufacturing process of electrode components, a pressing process is performed where the active material layer coated on the substrate is clamped between rollers and pressed to ensure its adhesion. Uncoated areas without the active material layer are formed on the substrate. During the pressing process, the rollers contact the active material layer but not the uncoated areas. Therefore, the coated areas with the active material layer elongate under pressing, while the uncoated areas are less likely to elongate, potentially creating a difference in elongation between the coated and uncoated areas. When using a substrate containing resin components, there is a concern that this difference in elongation may cause the uncoated areas to bend or wrinkle.

[0004] This disclosure was made in view of the aforementioned problems, and the object of this disclosure is to provide an electrode component capable of suppressing the generation of wrinkles and / or bending in uncoated areas where no active material layer is coated.

[0005] The electrode component based on this disclosure includes: a substrate comprising a resin substrate and a conductive layer formed on the resin substrate; and an active material layer formed on the conductive layer. The substrate has a coated area with the active material layer and an uncoated area without the active material layer. The resin substrate is composed of a crystalline polymer. The crystalline polymer located in the coated area has a higher crystallinity than the crystalline polymer located in the uncoated area.

[0006] Typically, in the manufacture of electrode components, a pressing process is performed where the active material layer and the substrate are clamped and pressed together using a pair of rollers to ensure that the active material layer is firmly attached to the substrate. During this pressing process, the coated area of ​​the substrate with the active material layer is clamped by the rollers, making it easier to elongate. On the other hand, the uncoated area of ​​the substrate without the active material layer is not clamped by the rollers, making it difficult to elongate.

[0007] In the above configuration, the resin substrate has high crystallinity in the easily elongated coated areas, thereby suppressing elongation in the coated areas. Conversely, in the pressing process, the resin substrate has low crystallinity in the difficult-to-elongate uncoated areas, thereby promoting elongation in these areas. As a result, the elongation difference between the uncoated and coated areas can be reduced. Consequently, the formation of wrinkles and / or deformation into curved shapes in the difficult-to-elongate areas where no active material layer has been formed can be suppressed.

[0008] In the electrode components based on the present disclosure, the crystalline polymer can be polypropylene.

[0009] Polypropylene is a material that is difficult to stretch compared to materials such as polyethylene. Therefore, by using polypropylene in a resin substrate, the elongation difference between the coated and uncoated areas of the resin substrate can be further reduced.

[0010] According to this disclosure, an electrode component can be provided that can suppress the generation of wrinkles and / or bending in uncoated areas where no active material layer is coated. Attached Figure Description

[0011] The features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, in which the same reference numerals denote the same elements, and wherein:

[0012] Figure 1 This is a perspective view of the battery according to Embodiment 1;

[0013] Figure 2 This is an exploded perspective view of the battery according to Embodiment 1;

[0014] Figure 3 Observe in the direction of the arrow on line III-III Figure 1 A cross-sectional view obtained from the battery;

[0015] Figure 4 Observe in the direction of the arrow on line IV-IV. Figure 3 A cross-sectional view obtained from the electrode body;

[0016] Figure 5 This is a cross-sectional view of the first electrode component of Embodiment 1 in its unfolded state; and

[0017] Figure 6 This is a cross-sectional view of the second electrode component of variant example 1 in its unfolded state. Detailed Implementation

[0018] Hereinafter, Embodiment 1 of the present disclosure will be described in detail with reference to the accompanying drawings. Furthermore, in Embodiment 1 shown below, the same or common parts will be labeled with the same reference numerals in the drawings, and their descriptions will not be repeated.

[0019] Implementation Method 1

[0020] Figure 1 This is a perspective view of the battery according to Embodiment 1. (e.g.) Figure 1 As shown, the battery 1 in this embodiment is a so-called prismatic battery. Battery 1 can be a rechargeable secondary battery, such as a lithium-ion battery or a nickel-metal hydride battery. Battery 1 can, for example, be used as a single battery included in an energy storage module mounted in an electrified vehicle.

[0021] Figure 2 This is an exploded perspective view of the battery according to Embodiment 1. Figure 3 Observe in the direction of the arrow on line III-III Figure 1 A cross-sectional view obtained from the battery. (e.g.) Figures 1 to 3 As shown, the battery 1 of Embodiment 1 includes an electrode body 10, a housing 20, a first external terminal 30A, a second external terminal 30B, a first connecting member 40A, a second connecting member 40B, a first sealing ring 50A, a second sealing ring 50B, a first terminal support portion 60A, a second terminal support portion 60B, an insulating member 70, and a fuse protection portion 80.

[0022] The housing 20 is conductive. The conductive parts of the housing 20 are made of a metal such as aluminum. The housing 20 houses the electrode body 10. The housing 20 also houses an electrolyte (not shown).

[0023] The housing 20 includes a housing body 21 and a cover 22. The housing body 21 includes a bottom wall 21a and a peripheral wall 21b rising from the bottom wall 21a.

[0024] The bottom wall 21a includes a bottom body 21aa, a pressure relief valve 21ab, an outer protective membrane 21ac, and an inner protective membrane 21ad. The peripheral wall 21b rises from the bottom body 21aa. The pressure relief valve 21ab is disposed on the bottom body 21aa. The outer protective membrane 21ac covers the pressure relief valve 21ab from the outside. The inner protective membrane 21ad covers the pressure relief valve 21ab from the inside. The bottom body 21aa and the pressure relief valve 21ab are made of metal such as aluminum.

[0025] An opening is formed at the upper end of the peripheral wall 21b. The peripheral wall 21b has a generally rectangular shape when viewed from the opening direction (the normal direction of the opening surface). The opening and the bottom wall 21a are aligned in a first direction D1. The first direction D1 can be the height direction of the battery 1 or the vertical direction. The peripheral wall 21b is made of a metal such as aluminum.

[0026] The cover 22 includes a cover body 22a, a sealing bolt 22b, a bolt cover 22c, and an insulating cover 22d.

[0027] The cover body 22a is joined to the peripheral wall 21b by welding or the like to close the opening of the peripheral wall 21b. A first connecting hole 22aa, a second connecting hole 22ab, and an electrolyte injection hole 22ac are formed in the cover body 22a. The electrolyte injection hole 22ac is a through hole for injecting electrolyte into the casing body 21 during the manufacturing process of the battery 1.

[0028] The sealing plug 22b seals the injection hole 22ac. The plug cover 22c covers the injection hole 22ac and the sealing plug 22b. The insulating cover 22d covers the injection hole 22ac, the sealing plug 22b, and the plug cover 22c.

[0029] The first external terminal 30A and the second external terminal 30B are arranged to be exposed to the outside in the battery 1. The first connecting structural member 40A and the second connecting structural member 40B are conductive. At least a portion of the first connecting structural member 40A and the second connecting structural member 40B is disposed inside the housing 20.

[0030] The first external terminal 30A or the first connecting member 40A is inserted into the first connecting hole 22aa. The first external terminal 30A and the first connecting member 40A are engaged with each other. The first connecting member 40A is engaged with the electrode body 10. Thus, the first external terminal 30A is electrically connected to the electrode body 10.

[0031] The second external terminal 30B or the second connecting member 40B is inserted into the second connecting hole 22ab. The second external terminal 30B and the second connecting member 40B are engaged with each other. The second connecting member 40B is engaged with the electrode body 10. Thus, the second external terminal 30B is electrically connected to the electrode body 10.

[0032] In this embodiment, the first external terminal 30A is the positive terminal and the second external terminal 30B is the negative terminal. The first external terminal 30A and the second external terminal 30B are arranged in the second direction D2. The second direction D2 is orthogonal to the first direction D1.

[0033] A first sealing ring 50A is disposed along the first connecting hole 22aa. The first sealing ring 50A is disposed in the gap between the cover body 22a and the first external terminal 30A, sealing the gap. A second sealing ring 50B is disposed along the second connecting hole 22ab. The second sealing ring 50B is disposed in the gap between the cover body 22a and the second external terminal 30B, sealing the gap. The first sealing ring 50A and the second sealing ring 50B are electrically insulating.

[0034] The first terminal support portion 60A is engaged with the cover body 22a. The first terminal support portion 60A supports the first external terminal 30A from its outer periphery. The first terminal support portion 60A includes a first locking ring 61A and a first covering ring 62A. The first locking ring 61A extends annularly around the first connecting hole 22aa and is directly engaged with the cover body 22a. The first covering ring 62A covers the first locking ring 61A. The first locking ring 61A supports the first external terminal 30A via the first covering ring 62A. The first covering ring 62A is made of a resin member having electrical insulation or relatively weak conductivity.

[0035] The second terminal support portion 60B is engaged with the cover body 22a. The second terminal support portion 60B supports the second external terminal 30B from its outer periphery. The second terminal support portion 60B includes a second locking ring 61B and a second covering ring 62B. The second locking ring 61B extends annularly around the second connecting hole 22ab and is directly engaged with the cover body 22a. The second covering ring 62B covers the second locking ring 61B. The second locking ring 61B supports the second external terminal 30B via the second covering ring 62B. The second covering ring 62B is made of an electrically insulating resin component.

[0036] The insulating member 70 is electrically insulating. The insulating member 70 is disposed between the plurality of electrode bodies 10 and the housing 20. The insulating member 70 electrically insulates the plurality of electrode bodies 10 from the housing 20. The insulating member 70 includes an insulating bracket 71, a peripheral insulating portion 72, and a bottom insulating portion 73.

[0037] An insulating bracket 71 is disposed between the plurality of electrode bodies 10 and the cover body 22a. The insulating bracket 71 has high rigidity and is in contact with both the electrode bodies 10 and the cover body 22a. Thus, the electrode bodies 10 are fixed to the housing 20 in the first direction D1.

[0038] A peripheral insulating portion 72 is disposed between the plurality of electrode bodies 10 and the peripheral wall 21b. The peripheral insulating portion 72 is composed of a film-like component.

[0039] A bottom insulating portion 73 is disposed between each electrode body 10 and the bottom wall 21a. The bottom insulating portion 73 is composed of a film-like component. In this embodiment, the bottom insulating portion 73 is bonded to the electrode body 10. Alternatively, the bottom insulating portion 73 only covers a portion of the bottom surface of the electrode body 10. Furthermore, the bottom insulating portion 73 may also completely cover the bottom surface.

[0040] like Figure 2As shown, the battery 1 of this embodiment includes a plurality of electrode bodies 10. Typically, the battery 1 includes two electrode bodies 10. These electrode bodies 10 are arranged in a third direction D3. The third direction D3 is a direction orthogonal to both the first direction D1 and the second direction D2. Furthermore, the peripheral insulating portion 72 can integrally cover the plurality of electrode bodies 10, thereby fixing these electrode bodies 10 to each other.

[0041] The electrode body 10 is provided with a plurality of first electrode tabs 150A and a plurality of second electrode tabs 150B. One end of the plurality of first electrode tabs 150A is connected to the first electrode member 11A described later (see reference). Figure 4 The first conductive layer 121 (refer to) Figure 5 ) and the second conductive layer 122 (refer to) Figure 5 The other ends of the plurality of first tabs 150A are joined to the aforementioned first connecting structural member 40A by means of ultrasonic welding or the like.

[0042] One end of the plurality of second electrode tabs 150B is connected to the second electrode member 11B described later (see reference). Figure 4 The second substrate 100B is connected. The other ends of the plurality of second tabs 150B are joined to the aforementioned second connecting structure 40B by means of ultrasonic welding or the like.

[0043] Figure 4 Observe in the direction of the arrow on line IV-IV. Figure 3 The cross-sectional view obtained from the electrode body. The electrode body 10 includes a first electrode member 11A, a second electrode member 11B, a separator 12, and a strip member 13. The electrode body 10 is wound around the winding axis Z with the first electrode member 11A, the second electrode member 11B, and the separator 12. In this embodiment 1, the case of the electrode body 10 being a wound electrode body is illustrated, but it is not limited to this. The electrode body 10 may also be a stacked electrode body in which the first electrode member 11A, the second electrode member 11B, and the separator 12 are stacked in one direction (e.g., the third direction D3). It should be noted that in Figure 4 In the middle, the separator 12 is schematically represented by a dashed line.

[0044] The first electrode member 11A and the second electrode member 11B have a sheet-like shape. The electrode body 10 is constructed by winding the first electrode member 11A and the second electrode member 11B with one or more separators 12 in between. The first electrode member 11A is, for example, a positive electrode, and the second electrode member 11B is a negative electrode.

[0045] The first electrode component 11A includes a first substrate 100A and a first active material layer 200A. The first active material layer 200A has the same polarity as the first electrode component 11A. The first active material layer 200A is, for example, a positive electrode active material layer. As the positive electrode active material layer, a known positive electrode active material layer can be used.

[0046] The first active material layer 200A is disposed on the surface and back side of the first substrate 100A. For a detailed description of the structure of the first substrate 100A, please refer to... Figure 5 To be described later.

[0047] The second electrode component 11B includes a second substrate 100B and a second active material layer 200B. The second active material layer 200B has the same polarity as the second electrode component 11B. The second electrode component 11B is, for example, a negative electrode active material layer. As the negative electrode active material layer, a known negative electrode active material layer can be used.

[0048] The second substrate 100B is made of a copper-containing metal component, such as copper foil. The second active material layer 200B is disposed on the surface and back side of the second substrate 100B.

[0049] A separator 12 is disposed between the first electrode member 11A and the second electrode member 11B. The separator 12 allows ions to move between the first electrode member 11A and the second electrode member 11B, and separates the first electrode member 11A and the second electrode member 11B. The ions are, for example, lithium ions. The separator 12 is electrically insulating.

[0050] In the electrode body 10, the separator 12 is located on the innermost circumferential side. Additionally, in the electrode body 10, the separator 12 is located on the outermost circumferential side. The outer circumferential edge of the separator 12 in the winding direction DR is fixed by a strip member 13 disposed on the outer circumferential surface of the separator 12.

[0051] The separator 12 may, for example, comprise a polyolefin resin. The separator 12 may, for example, be substantially composed of a polyolefin resin. The polyolefin resin may, for example, comprise at least one selected from polyethylene (PE) and polypropylene (PP).

[0052] Figure 5 This is a cross-sectional view of the first electrode component of Embodiment 1 in its unfolded state. Figure 5 A cross-sectional view of the first electrode member 11A at a section perpendicular to the second direction described above.

[0053] like Figure 5As shown, the first substrate 100A of the first electrode component 11A has a coated area R1 on which the first active material layer 200A is coated, and an uncoated area R2 on which the first active material layer 200A is not coated. In the first electrode component 11A, the first substrate 100A includes a first resin substrate 110 as a resin substrate, and a first conductive layer 121 and a second conductive layer 122 stacked on the first resin substrate 110.

[0054] The first resin substrate 110 has a first surface 110a and a second surface 110b in the thickness direction. Furthermore, the thickness direction is parallel to the lamination direction in which the first substrate 100A and the first active material layer 200A are laminated.

[0055] The first resin substrate 110 has a first portion 111 and a second portion 112 in a width direction orthogonal to the aforementioned lamination direction. Furthermore, in the wound state, the width direction becomes a direction parallel to the first direction D1.

[0056] Part 111 is located in the central part in the width direction. Part 111 overlaps with the first active material layer 200A in the stacking direction. Part 111 is located in the coating area R1.

[0057] Part 2 112 is located on both outer sides of Part 111 in the width direction. Part 2 112 does not overlap with the first active material layer 200A in the stacking direction. Part 2 112 is located in the uncoated region R2.

[0058] The first resin substrate 110 is composed of a crystalline polymer. Examples of crystalline polymers include polyethylene (PE), polypropylene (PP), polyamide (PA), polyethylene terephthalate (PET), and polyphenylene sulfide (PPS).

[0059] The crystallinity of the first resin substrate 110 (crystalline polymer) located in the coated area R1 is greater than that of the first resin substrate 110 (crystalline polymer) located in the uncoated area R2. It should be noted that the crystallinity can be measured using a differential scanning calorimeter (DSC).

[0060] A first conductive layer 121 is formed on a first surface 110a. The first conductive layer 121 is formed in both the coated region R1 and the uncoated region R2. A second conductive layer 122 is formed on a second surface 110b. The second conductive layer 122 is formed in both the coated region R1 and the uncoated region R2.

[0061] The first conductive layer 121 and the second conductive layer 122 are made of a metal component containing aluminum. The first conductive layer 121 and the second conductive layer 122 can also be formed on the first surface 110a and the second surface 110b by means of vapor deposition or the like. Alternatively, the first conductive layer 121 and the second conductive layer 122 can also be made of metal foil and bonded to the first surface 110a and the second surface 110b by an adhesive.

[0062] The first active material layer 200A is formed on the first conductive layer 121 and the second conductive layer 122. Specifically, the first active material layer 200A is formed on the first conductive layer 121 and the second conductive layer 122 at the central portion in the aforementioned width direction.

[0063] The first active material layer 200A has a first portion 210A and a second portion 220A. The first portion 210A is formed on the first conductive layer 121. The second portion 220A is formed on the second conductive layer 122.

[0064] Typically, in the manufacture of electrode components, a pressing process is performed whereby the first active material layer 200A and the first substrate 100A are clamped and pressed together using a pair of rollers in order to fix the first active material layer 200A onto the first substrate 100A. During the pressing process, the coated area R1 of the first substrate 100A, to which the first active material layer 200A is coated, is clamped by the pair of rollers, thus making it easy to elongate. On the other hand, the uncoated area R2 of the first substrate 100A, to which the first active material layer 200A is not formed, is not clamped by the pair of rollers, thus making it difficult to elongate.

[0065] In this embodiment, the crystallinity of the first resin substrate 110 in the easily elongated coated region R1 is higher than that in the difficult-to-elongate uncoated region R2, thereby suppressing the elongation of the coated region R1. Furthermore, during the pressing process, the crystallinity of the first resin substrate 110 in the difficult-to-elongate uncoated region R2 is low, thereby promoting elongation in the uncoated region R2. As a result, the elongation difference between the uncoated region R2 and the coated region R1 can be reduced. Consequently, the generation of wrinkles and / or deformation into a curved shape in the difficult-to-elongate region where the first active material layer 200A is not formed can be suppressed.

[0066] Furthermore, when polypropylene is used as the crystalline polymer constituting the first resin substrate 110, since polypropylene is a material that is difficult to stretch compared to polyethylene, the elongation difference between the coated area R1 and the uncoated area R2 of the first resin substrate 110 can be further reduced.

[0067] Variant Example 1

[0068] Figure 6 This is a cross-sectional view of the second electrode component of variant example 1 in its unfolded state. (Refer to...) Figure 6 The second electrode member 11X of Modified Example 1 will be described. Furthermore, the second electrode member 11X of Modified Example 1 can be applied to the electrode body 10 of Embodiment 1.

[0069] like Figure 6 As shown, the second electrode member 11X differs from the second electrode member 11B in embodiment 1 in the configuration of the second substrate 100B. Other configurations are largely the same.

[0070] like Figure 6 As shown, the second substrate 100B of the second electrode component 11X has a coated area R3 on which the second active material layer 200B is coated, and an uncoated area R4 on which the second active material layer 200B is not coated. In the second electrode component 11X, the second substrate 100B includes a second resin substrate 110X, and a third conductive layer 121X and a fourth conductive layer 122X stacked on the second resin substrate 110X.

[0071] The second resin substrate 110X has a first surface 110a1 and a second surface 110b1 in the thickness direction. Furthermore, the thickness direction is parallel to the lamination direction in which the second substrate 100B and the second active material layer 200B are laminated. The second resin substrate 110X has a first portion 111X and a second portion 112X in the width direction.

[0072] Part 111X is located in the central part in the width direction. Part 111X overlaps with the second active material layer 200B in the stacking direction. Part 111X is located in the coating area R3.

[0073] Part 2 112X is located on both outer sides of Part 1 111X in the width direction. Part 2 112X does not overlap with the second active material layer 200B in the stacking direction. Part 2 112X is located in the uncoated area R4.

[0074] The second resin substrate 110X is composed of a crystalline polymer. Examples of crystalline polymers include polyethylene (PE), polypropylene (PP), polyamide (PA), polyethylene terephthalate (PET), and polyphenylene sulfide (PPS).

[0075] The crystallinity of the second resin substrate 110X (crystalline polymer) located in the coated area R3 is greater than that of the second resin substrate 110X (crystalline polymer) located in the uncoated area R4.

[0076] A third conductive layer 121X is formed on the first surface 110a1. The third conductive layer 121X is formed in both the coated region R3 and the uncoated region R4. A fourth conductive layer 122X is formed on the second surface 110b1. The fourth conductive layer 122X is formed in both the coated region R3 and the uncoated region R4.

[0077] The third conductive layer 121X and the fourth conductive layer 122X are made of metal components containing copper. The third conductive layer 121X and the fourth conductive layer 122X can also be formed on the first surface 110a1 and the second surface 110b1 by means of vapor deposition or the like. Alternatively, the third conductive layer 121X and the fourth conductive layer 122X can also be made of metal foil and bonded to the first surface 110a1 and the second surface 110b1 by an adhesive.

[0078] The second active material layer 200B is formed on the third conductive layer 121X and the fourth conductive layer 122X. Specifically, the second active material layer 200B is formed on the third conductive layer 121X and the fourth conductive layer 122X at the central portion in the aforementioned width direction.

[0079] The second active material layer 200B has a first portion 210B and a second portion 220B. The first portion 210B is formed on the third conductive layer 121X. The second portion 220B is formed on the fourth conductive layer 122X.

[0080] Even when configured as described above, the second electrode member 11B of Modified Example 1 can achieve approximately the same effect as the first electrode member 11A of Embodiment 1.

[0081] Furthermore, in the battery having the second electrode member 11B of Modified Example 1, the crystallinity of the crystalline polymer in the coated region is higher than that in the uncoated region of both the first electrode member 11A and the second electrode member 11B. Therefore, the generation of wrinkles and / or bending in the uncoated region can be suppressed in both the first electrode member 11A and the second electrode member 11B.

[0082] Other variations

[0083] In the above-described embodiment 1, the case where the first electrode member 11A is a positive electrode and the second electrode member 11B is a negative electrode is illustrated, but it is not limited to this. Alternatively, the first electrode member 11A may be a negative electrode and the second electrode member 11B a positive electrode. In this case, each component constituting the first electrode member 11A and the second electrode member 11B uses a component with a polarity suitable for the substrate.

[0084] The embodiments and modifications disclosed herein are illustrative in all respects and are not restrictive. The scope of this invention is defined by the claims, which include all modifications within the meaning and scope equivalent to the claims.

Claims

1. An electrode component comprising: Substrate, comprising a resin substrate and a conductive layer formed thereon on the resin substrate; and An active material layer is formed on the conductive layer. The substrate has a coated area with the active substance layer and an uncoated area without the active substance layer. The resin substrate is composed of a crystalline polymer. The crystallinity of the crystalline polymer located in the coated area is greater than that of the crystalline polymer located in the uncoated area.

2. The electrode component according to claim 1, The crystalline polymer is polypropylene.

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