Power storage cell

Abstract

A capacitor cell comprises a wound electrode body including a positive electrode plate (first electrode), a negative electrode plate (second electrode), and a separator, and a fixing member for fixing the wound electrode body so as to maintain the wound state of the wound electrode body. The wound electrode body includes an end surface (first end surface) on one side in the Z direction (axial direction) where the winding axis extends, and an end surface (second end surface) on the other side in the Z direction. The fixing member is provided at least on the end surface.

Description

Technology Field

[0001] The present disclosure relates to a capacitor cell. Background Technology

[0002] International Publication No. 2018 / 105398 discloses a secondary battery having an electrode body in which a positive electrode and a negative electrode are wound in a wound shape with a separator interposed therebetween. A tape is attached to the outer surface of the electrode body to secure the end of the winding. The electrode body is housed in a case. The problem to be solved

[0003] In the above International Publication No. 2018 / 105398, the space between the outer surface of the electrode and the inner surface of the case is made small in order to restrict the movement of the electrode. Because of this, when the electrode expands, etc., the tape and the case interfere, and local pressure is generated at the location where the tape is attached.

[0004] The present disclosure is made to solve the above problem, and its purpose is to provide a capacitor cell capable of maintaining the wound state of a wound electrode while suppressing the occurrence of local pressure in the wound electrode. means of solving the problem

[0005] A capacitor cell according to one aspect of the present disclosure comprises a wound electrode body including a first electrode, a second electrode, and a separator disposed between the first electrode and the second electrode, and a fixing member for fixing the wound electrode body so as to maintain the wound state of the wound electrode body. The wound electrode body is wound such that the first electrode, the second electrode, and the separator surround the winding axis. The wound electrode body includes a first end surface on one side of the axial direction to which the winding axis extends, and a second end surface on the other side of the axial direction. The fixing member is provided at least on the first end surface.

[0006] In a capacitor cell according to one aspect of the present disclosure, a fixing member is provided on a first end surface as described above. Accordingly, the wound state of the wound electrode can be maintained by the fixing member on the first end surface without attaching a fixing tape to the side of the wound electrode. As a result, the wound state of the wound electrode can be maintained while suppressing local pressure caused by the attachment of the tape from occurring on the wound electrode.

[0007] In the capacitor cell according to the above-described phase, preferably, a fixing member is also provided on the second end surface. By configuring it in this way, the wound state of the wound electrode body can be maintained by utilizing the fixing member on the second end surface in addition to the fixing member on the first end surface. As a result, the wound state of the wound electrode body can be maintained more firmly.

[0008] In the capacitor cell according to the above-described phase, preferably, the wound electrode body includes a circumferential surface located between a first end surface and a second end surface. A fixing member is provided at a position closer to the circumferential surface than to the winding axis. By configuring it in this way, since the fixing member is positioned in the portion of the wound electrode body that is radially outer, it is possible to prevent the winding of the wound electrode body from unwinding in the radially outer direction.

[0009] In this case, preferably, the fixing member is provided to extend along the diameter direction of the wound electrode body between the winding axis and the circumferential surface. By configuring it in this way, the length of the fixing member in the diameter direction can be made relatively large, thereby maintaining the wound state of the wound electrode body even more firmly. Furthermore, compared to the case where the fixing member is not extended in the diameter direction, the portion of the wound electrode body inside the diameter direction can also be easily fixed by the fixing member. As a result, the unwinding of the wound electrode body inside the diameter direction can be suppressed during handling of the wound electrode body, etc.

[0010] The capacitor cell, in which the above-mentioned fixed member extends along the diameter direction, comprises a case having a cylindrical shape that accommodates a wound electrode body. The length of the fixed member in the diameter direction is less than or equal to the radius of the case. By configuring it in this way, even if two fixed members are arranged along the diameter direction, interference between the fixed members and the case can be suppressed.

[0011] In the capacitor cell according to the above-described phase, preferably, the wound electrode body includes a terminal end of the wound. A fixing member is provided at the terminal end. By configuring it in this way, the winding of the wound electrode body can be prevented from unwinding from the terminal end.

[0012] In the capacitor cell according to the above-described aspect, preferably, the wound electrode body includes an exposed portion in which no fixing member is disposed when viewed along the axial direction. By configuring it in this way, when the electrolyte is injected from the axial direction of the wound electrode body, the obstruction of the flow of the electrolyte by the fixing member can be suppressed compared to the case where the fixing member covers the entire surface of the wound electrode body.

[0013] In the capacitor cell according to the above-described aspect, preferably, the fixing member comprises a substrate and an adhesive layer provided on the substrate. The substrate is formed of an elastically deformable resin. By configuring it in this way, the substrate can be elastically deformed when the first electrode expands in the axial direction. This prevents the substrate from cracking.

[0014] In the capacitor cell according to the above-described phase, preferably, the first electrode comprises a first current collector and a first electrode material layer that is coated on a part of the first current collector and faces a separator in the diameter direction of the wound electrode body. The first current collector has a first coated portion where the first electrode material layer is coated, and a first uncoated portion where the first electrode material layer is not coated, located on a first end surface on one side in the axial direction from the first coated portion. A fixing member is provided in the first uncoated portion. By configuring it in this way, since the fixing member is provided in the first uncoated portion where the first electrode material layer is not coated, the load applied to the first electrode material layer by the fixing member during the expansion of the wound electrode body can be suppressed.

[0015] In the capacitor cell according to the above-described phase, preferably, the second electrode comprises a second current collector and a second electrode material layer that is coated on a part of the second current collector and faces the separator in the diameter direction. The second current collector has a second coated portion where the second electrode material layer is coated, and a second uncoated portion located on a second end surface on the axial side opposite to the second coated portion where the second electrode material layer is not coated. A fixing member is provided in the second uncoated portion. By configuring it in this way, since the fixing member is provided in the second uncoated portion where the second electrode material layer is not coated, the load applied to the second electrode material layer by the fixing member during the expansion of the wound electrode body can be suppressed.

[0016] According to the present disclosure, the wound state of the wound electrode can be maintained while suppressing the occurrence of local pressure in the wound electrode.

[0017] The above and other objects, features, aspects, and advantages of the present invention will become clear from the following detailed description according to the present invention, understood in conjunction with the accompanying drawings. Brief explanation of the drawing

[0018] FIG. 1 is a cross-sectional view showing the configuration of a capacitor cell according to one embodiment. FIG. 2 is a schematic perspective view showing the configuration of a wound electrode body according to one embodiment. Figure 3 is a magnified view of the positive pole side of Figure 1. Figure 4 is a magnified view of the negative side of Figure 1. FIG. 5 is a perspective view showing the configuration of a wound electrode body according to one embodiment. FIG. 6 is a plan view of a wound electrode body according to one embodiment, viewed from the Z1 side. FIG. 7 is a plan view of a wound electrode body according to one embodiment, viewed from the Z2 side. FIG. 8 is a cross-sectional view along line VIII-VIII of FIG. 5. FIG. 9 is a cross-sectional view along line IX-IX of FIG. 5. FIG. 10 is a plan view of a wound electrode body according to a first modified example of one embodiment, viewed from the Z1 side. FIG. 11 is a plan view of a wound electrode body according to a second modified example of one embodiment, viewed from the Z1 side. FIG. 12 is a plan view of a wound electrode body according to a third modified example of one embodiment, viewed from the Z1 side. FIG. 13 is a plan view of a wound electrode body according to a fourth modified example of one embodiment, viewed from the Z1 side. FIG. 14 is a side view of a wound electrode body according to a fifth modified example of one embodiment, viewed from the outer side in the diameter direction. FIG. 15 is a side view of a wound electrode body according to a sixth modified example of one embodiment, viewed from the outer side in the diameter direction. FIG. 16 is a perspective view of a wound electrode body according to a seventh modified example of one embodiment. Specific details for implementing the invention

[0019] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In addition, identical or substantial parts in the drawings are denoted by the same reference numerals, and their descriptions will not be repeated.

[0020] FIG. 1 is a cross-sectional view showing the overall configuration of a storage cell (100) according to an embodiment of the present disclosure. The storage cell (100) is, for example, a lithium-ion battery mounted in a vehicle. In addition, the use and type of the storage cell (100) are not limited to the above examples.

[0021] The capacitor cell (100) comprises a wound electrode body (1), a case (2), a positive electrode terminal (3), a positive electrode collector plate (4), an external gasket (5), an internal gasket (6), a negative electrode collector plate (7), and a fixing member (8) (see FIG. 2). Additionally, FIG. 1 is a cross-sectional view in a direction where the fixing member (8) is not visible.

[0022] The wound electrode body (1) is housed in a case (2). The case (2) has a cylindrical shape. That is, the capacitor cell (100) is a cylindrical battery. In addition, the case (2) is formed of copper or aluminum, etc.

[0023] The wound electrode body (1) includes a positive electrode plate (10), a negative electrode plate (20), and a separator (30). The separator (30) is provided between the positive electrode plate (10) and the negative electrode plate (20). The separator (30) separates the positive electrode plate (10) and the negative electrode plate (20) while enabling the movement of ions (e.g., lithium ions) between the positive electrode plate (10) (positive active material) and the negative electrode plate (20) (negative active material). The wound electrode body (1) is composed of a group of electrode plates in which the positive electrode plate (10) and the negative electrode plate (20) are wound with the separator (30) interposed. Additionally, the positive electrode plate (10) and the negative electrode plate (20) are each examples of the "first electrode" and "second electrode" of the present disclosure.

[0024] As shown in FIG. 2, the wound electrode body (1) is wound such that the positive electrode plate (10), the negative electrode plate (20), and the separator (30) surround the winding axis α. In FIG. 2, the wound state of the wound electrode body (1) is shown with the winding slightly unwound so that the wound state of the wound electrode body (1) is easily understood.

[0025] Referring again to FIG. 1, the positive terminal (3) includes a disk portion (3a) and a rivet portion (3b). The rivet portion (3b) is connected to the disk portion (3a). The rivet portion (3b) is provided to extend from the center of the disk portion (3a) toward the Z2 side. Additionally, the positive terminal (3) is formed of aluminum.

[0026] As shown in FIG. 3, the disk portion (3a) is positioned on the upper surface (2a) (Z1 side surface) of the case (2). A through hole (2b) is provided on the upper surface (2a) of the case (2). The rivet portion (3b) extends from the disk portion (3a), which is positioned on the outside of the case (2), through the through hole (2b) to the inside of the case (2).

[0027] The positive electrode collector plate (4) is housed in the case (2). The positive electrode collector plate (4) is welded to the positive electrode uncoated portion (11b) described later on the Z1 side of the wound electrode body (1). By this, the positive electrode collector plate (4) is positively charged. The positive electrode collector plate (4) is welded to the end (3c) on the Z2 side of the rivet portion (3b). By this, the positive electrode terminal (3) is positively charged.

[0028] The external gasket (5) is positioned between the disk portion (3a) of the positive terminal (3) and the upper surface (2a) of the case (2). By doing so, the positive terminal (3) and the case (2) are insulated.

[0029] The internal gasket (6) is positioned inside the case (2) between the case (2) and the positive electrode collector plate (4). As a result, the case (2) and the positive electrode collector plate (4) are insulated. Additionally, the rivet portion (3b) is in contact with the positive electrode collector plate (4) by penetrating the internal gasket (6).

[0030] The positive electrode plate (10) includes a positive electrode current collector (11) and a positive electrode composite layer (12). The positive electrode composite layer (12) is coated on both sides in the diameter direction (R direction) of the positive electrode current collector (11) (positive electrode coating portion (11a) described later). The positive electrode composite layer (12) faces the separator (30) in the R direction. Additionally, the positive electrode current collector (11) and the positive electrode composite layer (12) are each examples of a "first current collector" and a "first electrode material layer."

[0031] For the positive electrode current collector (11), materials such as aluminum are used. The positive electrode composite layer (12) is formed by coating a positive electrode slurry onto the surface of the positive electrode current collector (11) and drying it. The positive electrode slurry is a slurry prepared by mixing a solvent with a material of the positive electrode composite layer (12) (positive electrode active material, binder, etc.). The positive electrode composite layer (12) is in close contact with the separator (30). The thickness of the positive electrode composite layer (12) is, for example, 0.1 μm or more and 1000 μm or less.

[0032] The positive electrode collector (11) includes a positive electrode coated portion (11a) and a positive electrode uncoated portion (11b). The positive electrode coated portion (11a) is the part of the positive electrode collector (11) where the positive electrode composite layer (12) is coated. The positive electrode coated portion (11a) is sandwiched between the separators (30). Additionally, the positive electrode coated portion (11a) and the positive electrode uncoated portion (11b) are each examples of the “first coated portion” and “first uncoated portion” of the present disclosure.

[0033] The positive electrode uncoated portion (11b) is a portion of the positive electrode current collector (11) where the positive electrode composite layer (12) is not coated. The positive electrode uncoated portion (11b) is located on the Z1 side rather than the positive electrode coated portion (11a). Specifically, the positive electrode uncoated portion (11b) protrudes from the positive electrode coated portion (11a) toward the Z1 side. Furthermore, the Z1 side is an example of the “axial side” of the present disclosure.

[0034] The positive electrode coating portion (11b) includes a portion (11c) extending along the Z direction and a portion (11d) extending along the R direction. The positive electrode coating portion (11b) is bent inward in the diameter direction. The positive electrode coating portion (11b) is bent in an L-shape. The portion (11d) of the positive electrode coating portion (11b) is in contact with the positive electrode collector plate (4). As a result, the positive electrode collector plate (4) is positively charged. Additionally, the positive electrode coating portion (11b) (part (11d)) is joined to the positive electrode collector plate (4) by welding.

[0035] The positive electrode coatings (11b) are arranged in multiple parallel along the winding direction. A slit (11g) (see FIG. 5) is provided between adjacent positive electrode coatings (11b) in the winding direction. Among the multiple positive electrode coatings (11b), the positive electrode coatings (11b) adjacent in the R direction are arranged to partially overlap each other.

[0036] As shown in FIG. 4, the negative electrode collector plate (7) is housed in the case (2). The negative electrode collector plate (7) is welded to the negative electrode uncoated portion (21b) described later on the negative electrode plate (20) on the Z2 side of the wound electrode body (1). By this, the negative electrode collector plate (7) is negatively charged. Additionally, the negative electrode collector plate (7) is in contact with the case (2). By this, the case (2) is negatively charged.

[0037] The negative electrode plate (20) includes a negative electrode current collector (21) and a negative electrode composite layer (22). The negative electrode composite layer (22) is coated on both sides in the diameter direction (R direction) of the negative electrode current collector (21) (negative electrode coating portion (21a) described later). The negative electrode composite layer (22) faces the separator (30) in the R direction. Additionally, the negative electrode current collector (21) and the negative electrode composite layer (22) are each examples of the "second current collector" and "second electrode material layer" of the present disclosure.

[0038] For the negative electrode current collector (21), for example, copper is used. The negative electrode composite layer (22) is formed by coating the surface of the negative electrode current collector (21) with a negative electrode slurry and drying it. The negative electrode slurry is a slurry prepared by mixing a solvent with the material of the negative electrode composite layer (22) (such as a negative electrode active material or binder). The negative electrode composite layer (22) is in close contact with the separator (30). The thickness of the negative electrode composite layer (22) is, for example, 0.1 μm or more and 1000 μm or less.

[0039] The negative electrode current collector (21) includes a negative electrode coated portion (21a) and a negative electrode uncoated portion (21b). The negative electrode coated portion (21a) is the part of the negative electrode current collector (21) where the negative electrode composite layer (22) is coated. The negative electrode coated portion (21a) is sandwiched between the separators (30). Additionally, the negative electrode coated portion (21a) and the negative electrode uncoated portion (21b) are each examples of the “second coated portion” and “second uncoated portion” of the present disclosure.

[0040] The negative electrode uncoated portion (21b) is a portion of the negative electrode current collector (21) where the negative electrode composite layer (22) is not coated. The negative electrode uncoated portion (21b) is located on the Z2 side rather than the negative electrode coated portion (21a). Specifically, the negative electrode uncoated portion (21b) protrudes from the negative electrode coated portion (21a) toward the Z2 side. Furthermore, the Z2 side is an example of the “other side in the axial direction” of the present disclosure.

[0041] The negative electrode uncoated portion (21b) includes a portion (21c) extending along the Z direction and a portion (21d) extending along the R direction. The negative electrode uncoated portion (21b) is bent inward in the diameter direction. The negative electrode uncoated portion (21b) is bent in an L-shape. The portion (21d) of the negative electrode uncoated portion (21b) is in contact with the negative electrode collector plate (7). As a result, the negative electrode collector plate (7) is negatively charged. Additionally, the negative electrode uncoated portion (21b) (part (21d)) is joined to the negative electrode collector plate (7) by welding.

[0042] Additionally, multiple negative electrode coating sections (21b) are arranged side by side along the winding direction. A slit (21g) (see FIG. 5) is provided between adjacent negative electrode coating sections (21b) in the winding direction. Furthermore, among the multiple negative electrode coating sections (21b), the negative electrode coating sections (21b) adjacent in the R direction are arranged to partially overlap each other.

[0043] As illustrated in FIG. 5, the wound electrode body (1) includes an end surface (1a), an end surface (1b), a circumferential surface (1c), and a terminal end (1d). The end surface (1a) is the end surface on the Z1 side of the wound electrode body (1). The end surface (1b) is the end surface on the Z2 side of the wound electrode body (1). The circumferential surface (1c) is the outer surface of the wound electrode body (1) located between the end surface (1a) and the end surface (1b). The terminal end (1d) is the wound terminal end of the wound electrode body (1).

[0044] Here, in the configuration of a conventional capacitor cell, a fixing tape is attached to the side of the wound electrode to maintain the wound state of the wound electrode. Additionally, to restrict the movement of the wound electrode, the space between the side of the wound electrode and the inner surface of the case is made small. Consequently, when the wound electrode expands, the tape and the case interfere, and localized pressure is generated at the location where the tape is attached.

[0045] Accordingly, in this embodiment, as shown in FIGS. 2 and FIGS. 5, a fixing member (8) is provided on the end surface (1a). The fixing member (8) is a member that fixes the wound electrode body (1) so as to maintain the wound state of the wound electrode body (1). The end surface (1a) is formed by a positive electrode uncoated portion (11b) that is provided to be wound around the circumference of the wound axis α.

[0046] That is, the fixing member (8) is provided in the positive electrode fine coating section (11b). Specifically, the fixing member (8) is installed in the part (11d) of the positive electrode fine coating section (11b).

[0047] Two fixing members (8) are provided on the end surface (1a). The two fixing members (8) on the end surface (1a) are provided on opposite sides (facing each other) with the winding axis α in between. That is, the two fixing members (8) on the end surface (1a) are provided on a straight line passing through the winding axis α.

[0048] A fixed member (8) is also provided on the end surface (1b). The end surface (1b) is formed by a negative electrode uncoated section (21b) that is provided to be wound around the circumference of the winding axis α. That is, the fixed member (8) is provided on the negative electrode uncoated section (21b). Specifically, the fixed member (8) is installed on a portion (21d) of the negative electrode uncoated section (21b).

[0049] Two fixing members (8) are provided on the end surface (1b). The two fixing members (8) on the end surface (1b) are provided on opposite sides of each other with the winding axis α in between. That is, the two fixing members (8) on the end surface (1b) are provided on a straight line passing through the winding axis α.

[0050] Additionally, one or more fixing members (8) may be provided on each of the end surface (1a) and the end surface (1b). Also, the number of fixing members (8) provided on the end surface (1a) and the number of fixing members (8) provided on the end surface (1b) may be different.

[0051] The fixing member (8) in the end surface (1a) is provided in a position that overlaps (matches) the fixing member (8) in the Z direction with the fixing member (8) in the end surface (1b).

[0052] One of the two fixing members (8) in each of the end surface (1a) and end surface (1b) is provided at the end portion (1d). Specifically, the fixing member (8) and the end portion (1d) overlap (are adjacent) in the diameter direction (R direction) of the wound electrode body (1) when viewed from the Z1 side. Additionally, the fixing member (8) may not be provided at a position that overlaps with the end portion (1d) in the diameter direction, but may be provided near the end portion (1d) in the circumferential direction.

[0053] As shown in FIG. 6, the fixing member (8) is installed in the portion (11e) provided on the outer circumference (1e) of the wound electrode body (1) among the positive electrode uncoated portions (11b) (part (11d)). That is, the portion (11e) is the positive electrode uncoated portion (11b) that protrudes toward the Z1 side from the positive electrode coated portion (11a) that is wound furthest outward in the diameter direction among the positive electrode current collectors (11). Also, in FIG. 6, the fixing member (8) is shown diagonally.

[0054] Additionally, the fixed member (8) is installed in a plurality of parts (11f) arranged in the inner diameter direction with respect to part (11e) of the positive electrode uncoated part (11b) (part (11d)) when viewed from the Z1 side. Part (11f) is a positive electrode uncoated part (11b) that protrudes toward the Z1 side from the positive electrode coated part (11a) which is wound in the inner diameter direction rather than the positive electrode coated part (11a) which is wound in the outer diameter direction. That is, part (11f) is a part that protrudes from the positive electrode coated part (11a) at a position closer to the winding axis α than the position where part (11e) protrudes from the positive electrode coated part (11a).

[0055] The fixing member (8) is provided across a portion (11e) and a plurality of portions (11f) arranged side by side in the radial direction. By this, the portion (11e) and the plurality of portions (11f) are bonded to each other by an adhesive layer (8d) described later. Additionally, adjacent positive electrode uncoated portions (11b) in the radial direction are provided to partially overlap each other in the Z direction (parts (11e) and parts (11f) / parts (11f) together).

[0056] The fixed member (8) is provided to extend along the diameter direction of the wound electrode body (1) between the winding axis α and the circumferential surface (1c) (the outer circumference (1e) of the wound electrode body (1)). The fixed member (8) is provided to extend inward in the diameter direction from the portion (11e). The fixed member (8) has a rectangular shape (see FIG. 6) in which the side extending in the diameter direction is the longer side. In addition, when the diameter r (see FIG. 1) of the case (2) is, for example, 46 mm, it is preferable that the length L1 (see FIG. 6) of the fixed member (8) in the diameter direction is 1 mm or more and 23 mm or less (i.e., less than or equal to the radius of the case (2)). By doing so, it is possible to suppress interference between the fixed member (8) and the case (2). In addition, the diameter r may be the outer diameter of the case (2).

[0057] The fixed member (8) is positioned closer to the circumferential surface (1c) than to the winding axis α. Specifically, when viewed from one side in the axial direction (Z1 side), the distance D1 between the outer end (8a) in the diameter direction of the fixed member (8) and the circumferential surface (1c) (outer periphery (1e)) is smaller than the distance D2 between the inner end (8b) in the diameter direction of the fixed member (8) and the winding axis α. Additionally, when viewed from the Z1 side, the distance D1 is smaller than the distance D3 between the inner periphery (11h) of the end surface (1a) and the end (8b). Furthermore, the phrase “viewed from the Z1 side” means viewing the winding electrode body (1) from point P1 (see FIG. 5) on the winding axis α on the Z1 side of the winding electrode body (1).

[0058] As can be seen from the above description, the wound electrode body (1) includes an exposed portion in which the fixed member (8) is not positioned and is exposed when viewed along the axial direction. That is, the fixed member (8) is provided in a part of the wound electrode body (1) when viewed from the Z1 side. In the example illustrated in FIG. 6, the exposed portion refers to a portion other than the area where the fixed member (8) is provided.

[0059] The negative electrode side is configured in the same way. Specifically, as shown in FIG. 7, the fixing member (8) is installed in the part (21e) provided on the outer circumference (1e) of the wound electrode body (1) among the negative electrode uncoated portions (21b) (part (21d)). That is, the part (21e) is the negative electrode uncoated portion (21b) that protrudes toward the Z2 side from the negative electrode coated portion (21a) that is wound furthest outward in the diameter direction among the negative electrode current collectors (21). Also, in FIG. 7, the fixing member (8) is indicated by a diagonal line for ease of understanding.

[0060] Additionally, the fixed member (8) is installed in a plurality of parts (21f) arranged in the inner diameter direction with respect to part (21e) of the negative electrode uncoated part (21b) (part (21d)) when viewed from the Z2 side. Part (21f) is a negative electrode uncoated part (21b) that protrudes toward the Z2 side from the negative electrode coated part (21a) which is wound in the inner diameter direction rather than the negative electrode coated part (21a) which is wound in the outer diameter direction. That is, part (21f) is a part that protrudes from the negative electrode coated part (21a) at a position closer to the winding axis α than the position where part (21e) protrudes from the negative electrode coated part (21a). Furthermore, the phrase “viewed from the Z2 side” means viewing the wound electrode body (1) from point P2 (see FIG. 5) on the winding axis α on the Z2 side of the wound electrode body (1).

[0061] The fixing member (8) is provided across a portion (21e) and a plurality of portions (21f) arranged side by side in the radial direction. By this, the portion (21e) and the plurality of portions (21f) are bonded to each other by an adhesive layer (8d) described later. Additionally, adjacent negative electrode uncoated portions (21b) in the radial direction are provided to partially overlap each other in the Z direction (parts (21e) and parts (21f) / parts (21f) together).

[0062] In addition, regarding the position and shape of the fixing member (8) in the end surface (1b), since it is the same as the fixing member (8) in the end surface (1a) described above, a repeated explanation is omitted.

[0063] FIG. 8 is a cross-sectional view along line VIII-VIII of FIG. 5. The fixing member (8) includes a substrate (8c) and an adhesive layer (8d) provided on the substrate (8c). The adhesive layer (8d) is applied to the surface of the substrate (8c). The fixing member (8) is positioned on the wound electrode body (1) with the adhesive layer (8d) facing toward the wound electrode body (1) side (Z2 side). As a result, the positive electrode uncoated portions (11b) arranged in the diameter direction are bonded to each other by the adhesive layer (8d) (parts (11e) and parts (11f) / parts (11f) together). Additionally, the portions (11e, 11f) in contact with the fixing member (8) are not in contact with the positive electrode collector plate (4).

[0064] FIG. 9 is a cross-sectional view along line IX-IX of FIG. 5. A fixing member (8) is placed on a wound electrode body (1) with the adhesive layer (8d) facing toward the wound electrode body (1) side (Z1 side). As a result, the negative electrode uncoated portions (21b) arranged in the diameter direction are bonded to each other by the adhesive layer (8d) (parts (21e) and parts (21f) / parts (21f) together). Additionally, the portions (21e, 21f) in contact with the fixing member (8) are not in contact with the negative electrode collector plate (7).

[0065] In this embodiment, the substrate (8c) is formed from an elastically deformable resin. That is, the substrate (8c) is formed from a resin with a low elastic modulus. The type of substrate (8c) is determined by considering the expansion amount of the wound electrode body (1) (e.g., negative electrode plate (20)). Specifically, a substrate (8c) capable of deformation greater than the expansion amount (within an allowable range) is selected. For example, the substrate (8c) may be formed from an epoxy resin.

[0066] As described above, in this embodiment, the fixing member (8) is provided on the end surface [1a (1b)] of the wound electrode body (1). By doing so, the fixing member (8) for maintaining the wound state of the wound electrode body (1) can be placed on one side (the other side) of the axial direction of the wound electrode body (1) where there is relatively more space. By doing so, interference between the fixing member (8) and the case (2) can be suppressed even when the wound electrode body (1) expands. As a result, the wound state of the wound electrode body can be maintained while suppressing local pressure from occurring on the wound electrode body.

[0067] In the above embodiment, an example is shown in which the fixing member (8) is provided on the portion (11e) of the outer circumference (1e) (end portion (1d)) of the wound electrode body (1), but the present disclosure is not limited thereto. The fixing member (8) does not have to be provided on the portion (11e) of the outer circumference (1e) (end portion (1d)). For example, in the example shown in FIG. 10, the fixing member (18) is provided on the inner side in the radial direction from the portion (11e) of the outer circumference (1e). The negative electrode side may be configured in the same way.

[0068] In the above embodiment, an example is shown in which the fixed member (8) is positioned closer to the circumferential surface (1c) than to the winding axis α, but the present disclosure is not limited thereto. For example, as shown in FIG. 11, the fixed member (28) may be positioned closer to the winding axis α than to the circumferential surface (1c) (outer periphery (1e)). In addition, it may be configured in the same way on the negative side.

[0069] In the above embodiment, an example is shown in which the fixing member (8) is provided to extend in the radial direction, but the present disclosure is not limited thereto. The fixing member (8) does not have to be extended in the radial direction. For example, in the example shown in FIG. 12, the fixing member (8) is provided to extend in directions that intersect the radial direction and the circumferential direction, respectively. In addition, the negative side may be configured in the same way.

[0070] In the above embodiment, an example is shown in which a fixing member (8) having a rectangular shape is formed in a straight line along the diameter direction, but the present disclosure is not limited thereto. For example, as shown in FIG. 13, a plurality of fixing members (38) may be arranged side by side along the diameter direction. In addition, the fixing member may not be rectangular but circular (e.g., perfect circle, ellipse, and oblong). In addition, only one of the plurality of fixing members (38) in FIG. 13 may be provided.

[0071] In the above embodiment, an example is shown in which a fixing member (8) is formed on each of the end surface (1a) and the end surface (1b), but the present disclosure is not limited thereto. The fixing member (8) may be provided on only one of the end surface (1a) and the end surface (1b). FIG. 14 illustrates an example in which the fixing member (8) is provided only on the end surface (1a).

[0072] In the above embodiment, an example is shown in which a fixing member (8) is provided on a tapless type wound electrode body (1) in which the uncoated portion (11b, 21b) protrudes axially from the coated portion (11a, 21a), but the present disclosure is not limited thereto. As shown in FIG. 15, a fixing member (8) may be provided on a wound electrode body (31) comprising a tap lead (111) installed on a positive electrode plate (110) and a tap lead (121) installed on a negative electrode plate (120).

[0073] In the above embodiment, an example is shown in which each of the positive electrode uncoated portion (11b) and the negative electrode uncoated portion (21b) is bent inward in the diameter direction, but the present disclosure is not limited thereto. At least one of the positive electrode uncoated portion (11b) and the negative electrode uncoated portion (21b) may be bent outward in the diameter direction.

[0074] In the above embodiment, an example is shown in which a slit (11g) is provided between a plurality of positive electrode coating portions (11b), but the present disclosure is not limited thereto. A slit does not need to be provided in the positive electrode coating portion. That is, the positive electrode current collector may include a single positive electrode coating portion wound around the winding axis α. The same may apply to the negative electrode side.

[0075] In the above embodiment, an example is shown in which a plurality of positive electrode uncoated portions (11b) including portions (11c) and (11d) are provided, but the present disclosure is not limited thereto. A plurality of portions (11d) may be connected to a single portion (a portion corresponding to portion (11c)) extending in the winding direction. The same may be true for the negative electrode side.

[0076] In the above embodiment, an example is shown in which two fixing members (8) are arranged side by side in the diameter direction, but the present disclosure is not limited thereto. As shown in FIG. 16, one fixing member (48) may be extended in the diameter direction through the winding center of the wound electrode body (1). In addition, when the diameter r (see FIG. 1) of the case (2) is 46 mm, it is preferable that the length L2 of the fixing member (48) in the diameter direction be 46 mm or less. By doing so, it is possible to suppress interference between the fixing member (48) and the case (2).

[0077] In addition, the configurations of the above embodiments and each of the above variations may be combined with each other.

[0078] Although embodiments of the present invention have been described, the embodiments disclosed herein should be considered illustrative in all respects and not restrictive. The scope of the present invention is exemplified by the claims, and all modifications within the meaning and scope equivalent to the claims are intended to be included.

Claims

Claim 1 A capacitor cell comprising a wound electrode body including a first electrode, a second electrode, and a separator disposed between the first electrode and the second electrode, and a fixing member for fixing the wound electrode body so as to maintain the wound state of the wound electrode body, wherein the wound electrode body is wound such that the first electrode, the second electrode, and the separator surround the winding axis, and the wound electrode body includes a first end surface on one side of the axial direction to which the winding axis extends and a second end surface on the other side of the axial direction, and the wound electrode body includes a periphery surface located between the first end surface and the second end surface, and the fixing member is provided at least on the first end surface and extends along the diameter direction of the wound electrode body between the winding axis and the periphery surface, and is provided not to extend to the periphery surface. Claim 2 In claim 1, the fixed member is a capacitor cell that is also provided on the second end surface. Claim 3 In claim 1 or 2, the fixed member is a capacitor cell provided at a position closer to the circumferential surface than to the winding axis. Claim 4 delete Claim 5 A capacitor cell according to claim 1, further comprising a cylindrical case accommodating the wound electrode body, wherein the length of the fixed member in the diameter direction is less than or equal to the radius of the case. Claim 6 A capacitor cell according to claim 1 or 2, wherein the wound electrode body includes a winding end portion, and the fixed member is provided adjacent to the end portion in the diameter direction of the wound electrode body when the wound electrode body is viewed at a position spaced apart from the wound electrode body in the axial direction. Claim 7 A capacitor cell according to claim 1 or 2, wherein the wound electrode body includes an exposed portion where the fixed member is not disposed when viewed along the axial direction. Claim 8 A capacitor cell according to claim 1 or 2, wherein the fixing member comprises a substrate and an adhesive layer provided on the substrate, and the substrate is formed by an elastically deformable resin. Claim 9 A capacitor cell according to claim 1 or 2, wherein the first electrode comprises a first current collector and a first electrode material layer facing the separator in the diameter direction of the wound electrode body, which is coated on a part of the first current collector, and the first current collector has a first coated portion where the first electrode material layer is coated and a first uncoated portion where the first electrode material layer is not coated, which is located on one side in the axial direction from the first coated portion, and the fixing member is provided on the first end surface formed by the first uncoated portion. Claim 10 In paragraph 2, the second electrode comprises a second current collector and a second electrode material layer facing the separator in the diameter direction of the wound electrode body, which is coated on a part of the second current collector, and the second current collector has a second coated portion where the second electrode material layer is coated and a second uncoated portion where the second electrode material layer is not coated, which is located on the other side in the axial direction from the second coated portion, and the fixing member is provided on the second end surface formed by the second uncoated portion, forming a capacitor cell.

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