Stacked electrode assembly and power storage module

Abstract

A laminated electrode body comprises a plurality of electrodes and a plurality of separators. Each electrode and each separator is alternately laminated in a first direction. The laminated electrode body extends in a second direction perpendicular to the first direction. The laminated electrode body further comprises a periphery surface extending in the second direction. The length of each separator in a third direction perpendicular to the first and second directions is longer than the length of each electrode in the third direction. The periphery surface has first and second main surfaces on the first direction side and first and second side surfaces on the third direction side, each of which is continuous with the first and second main surfaces. On at least one of the first side surface and the second side surface, each separator is welded along the length of the first direction of the laminated electrode body.

Description

Technology Field

[0001] The present disclosure relates to a stacked electrode body and a capacitor module. Background Technology

[0002] Conventionally, a storage module is known. Japanese Patent Publication No. 2012-209054 discloses an electrode stack (stacked electrode body) of a stacked battery, which is a storage module. The electrode stack is formed by stacking a plurality of electrodes, each arranged between separators. The electrode stack has a separator joint formed by joining the stacked plurality of separators together, provided at multiple positions around the electrodes. The multiple positions are positions that restrict the movement of the electrodes in a direction intersecting the stacking direction of the electrode stack.

[0003] In Japanese Patent Publication No. 2012-209054, the position of the separator junction with respect to the stacking direction of the electrode stack is the same as the position of the separator placed at the bottom or middle of the stacking direction. A portion of each separator, excluding the separator placed at the bottom or middle, extends toward the separator junction from the outer edge of each stacked positive electrode and negative electrode. Therefore, in Japanese Patent Publication No. 2012-209054, a large space that does not contribute to charging and discharging must be taken from the outer edge of each stacked positive electrode and each negative electrode to the separator junction.

[0004] The present disclosure provides a stacked electrode body capable of suppressing space that does not contribute to charging and discharging while preventing positional misalignment of each separator.

[0005] According to one aspect of the present disclosure, a laminated electrode body comprises a plurality of electrodes and a plurality of separators. Each electrode and each separator is alternately laminated in a first direction. The laminated electrode body extends in a second direction perpendicular to the first direction. The laminated electrode body further comprises a periphery surface extending in the second direction. The length of each separator in a third direction perpendicular to the first direction and the second direction is longer than the length of each electrode in the third direction. The periphery surface has a first and second main surface on the first direction side and a first and second side surface on the third direction side, each of which is continuous with the first and second main surfaces. On at least one of the first side surface and the second side surface, each separator is welded along the length of the first direction of the laminated electrode body.

[0006] According to the above configuration, each separator is welded along the length of the first direction of the laminated electrode body on at least one of the first side and the second side. Therefore, movement of each separator in the third direction within the laminated electrode body is restricted. Thus, it is possible to prevent misalignment of the position of each separator. In addition, according to the above configuration, the amount of protrusion of each separator from the outer edge of each electrode can be suppressed. Thus, it is possible to suppress the space that does not contribute to charging and discharging.

[0007] Preferably, each separator is welded to each other along the length of the first direction of the laminated electrode body at each of a plurality of locations separated in the second direction.

[0008] According to the above configuration, the electrolyte can be impregnated into the interior of the laminated electrode body from a location where the second side is not welded. Therefore, it becomes easier to impregnate the electrolyte into the interior of the laminated electrode body than when the entire second side is welded.

[0009] According to another aspect of the present disclosure, a capacitor module comprises a stacked electrode body and a receptacle for receiving the stacked electrode body. The receptacle has an injection hole formed therein for injecting an electrolyte into the receptacle. The injection hole is formed at the end of the receptacle on the second direction side and is also closer to the first side than the second side. Each separator is welded only on the second side among the first side and the second side.

[0010] According to the above configuration, the electrolyte is more likely to pass through the first side than the second side. Although the flow of the electrolyte into the laminated electrode body is obstructed by the welded portion, since the welded portion is located only on the second side, the electrolyte is more likely to be impregnated into the laminated electrode body compared to when it is located on the first side. Therefore, according to the capacitor module, the electrolyte can be efficiently impregnated into the interior of the laminated electrode body when injected into the electrolyte receptacle compared to when the injection hole is formed on the second side rather than the first side.

[0011] Preferably, each separator is welded to each other along the length of the first direction of the laminated electrode body at each of a plurality of locations separated in the second direction. The length of each of the plurality of locations in the second direction is shorter the further the location is from the injection hole.

[0012] When the electrolyte is injected into the receiver, most of the electrolyte is not immediately impregnated into the laminated electrode body, but first passes around the laminated electrode body and moves to the side opposite to the injection hole. After that, the electrolyte moves within the laminated electrode body (100) from the side opposite to the injection hole toward the injection hole side by capillary action. Through this action, the electrolyte can be supplied throughout the entire interior of the laminated electrode body. In addition, as the amount of electrolyte injected increases over time, the electrolyte can also be supplied into the laminated electrode body from the surroundings. As described above, since the length of the second direction is shorter the further the location is from the injection hole, the electrolyte can be efficiently impregnated into the interior of the laminated electrode body (100C) starting from the part of the second side of the laminated electrode body that is far from the injection hole.

[0013] The above and other objects, features, aspects, and advantages of the present invention will become apparent from the following detailed description of the invention, which is understood in conjunction with the accompanying drawings. Brief explanation of the drawing

[0014] Figure 1 is a perspective view of a capacitor module. Figure 2 is a figure showing a stacked electrode body included in the capacitor module of Figure 1. Figure 3 is a cross-sectional view taken along the line arrow III-III of Figure 1. FIG. 4 is a view of the stacked electrode body of FIG. 3 seen in a predetermined direction. FIG. 5 is a figure showing a first modified example of a stacked electrode body. FIG. 6 is a figure showing a second modified example of a stacked electrode body. FIG. 7 is a figure showing a third modified example of a stacked electrode body. FIG. 8 is a figure showing a fourth modified example of a stacked electrode body. FIG. 9 is a figure showing a fifth modified example of a stacked electrode body. FIG. 10 is a figure showing a sixth modified example of a stacked electrode body. Figure 11 is a cross-section of another capacitor module. Specific details for implementing the invention

[0015] Hereinafter, each embodiment of the present disclosure will be described in detail with reference to the drawings. In addition, in each embodiment shown below, the same reference numerals in the drawings are assigned to identical or common parts, and the description thereof is not repeated.

[0016] [Embodiment 1]

[0017] FIG. 1 is a perspective view of a capacitor module related to the present embodiment. FIG. 2 is a diagram showing a stacked electrode body included in the capacitor module of FIG. 1. As shown in FIG. 1 and FIG. 2, the capacitor module (1) has a blade shape. The capacitor module (1) comprises a stacked electrode body (100) and a receiver (2) that accommodates the stacked electrode body (100). Furthermore, for convenience of explanation, the capacitor module (1) will be described below by taking an example in which the capacitor module (1) assumes a position in which the D3 direction shown in FIG. 1, FIG. 2, etc. is a vertical direction (more specifically, the D31 direction described below is a vertical upward direction), except when the electrolyte is injected as described later.

[0018] In this example, the battery module (1) is a lithium iron phosphate (LFP) type battery. However, it is not limited thereto, and the battery module (1) may be a ternary (NMC) type battery. The battery module (1) is mounted, for example, in an electric vehicle that runs on driving power obtained from electric energy. Specifically, a battery pack comprising a plurality of battery modules (1) arranged side by side in a predetermined direction is mounted in the electric vehicle. The battery pack is mounted on the vehicle body of the electric vehicle. The battery pack constitutes a part of the vehicle body. The battery pack is made to function as a structural element of the vehicle body.

[0019] As shown in FIG. 1, the receptor (2) is approximately rectangular in shape. In this example, the receptor (2) is a metal case. The receptor (2) has first to sixth surfaces (21 to 26). The first surface (21), the second surface (22), the third surface (23), and the fourth surface (24) are continuous in this order. The first surface (21), the second surface (22), the third surface (23), and the fourth surface (24) form the outer surface of the receptor (2).

[0020] The fifth side (25) and the sixth side (26) are cross-sections of the receiver (2). The first side (21) is the top surface, the second side (22) is the bottom surface, and the third side (23) and the fourth side (24) are the sides. On the fifth side (25), an external connection terminal (27) for the negative side is provided. On the sixth side (26), an external connection terminal (not shown) for the positive side is provided.

[0021] As shown in FIG. 2, the stacked electrode body (100) has a plurality of electrodes (negative electrode (110), positive electrode (120)) and a plurality of separators (130). In the stacked electrode body (100), the plurality of electrodes are stacked in the D1 direction (stacking direction). Specifically, in the stacked electrode body (100), each negative electrode (110) and each positive electrode (120) are alternately stacked in the D1 direction with the separator (130) interposed. That is, in the stacked electrode body (100), the negative electrode (110), the separator (130), the positive electrode (120), and the separator (130) are arranged repeatedly in this order. Also, the D1 direction is the width direction of the capacitor module (1). The size of each positive electrode (120) is the same. The size of each negative electrode (110) is the same. The size of each separator (130) is the same.

[0022] The length of each separator (130) in the D3 direction is longer than the length of each positive pole (120) in the D3 direction. Likewise, the length of each separator (130) in the D3 direction is longer than the length of each negative pole (110) in the D3 direction.

[0023] The laminated electrode body (100) further comprises a tab (150) connected to an external connection terminal (27) on the negative side and a tab (160) connected to an external connection terminal on the positive side. The tab (150) is formed by packing copper foil. The tab (160) is formed by packing aluminum foil.

[0024] As shown in FIG. 1, the capacitor module (1) and the receptacle (2) are extended in the D2 direction. As shown in FIG. 2, the stacked electrode body (100) is extended in the D2 direction. The D2 direction is perpendicular to the D1 direction. The D2 direction is the length direction of the capacitor module (1), the receptacle (2), and the stacked electrode body (100). The D3 direction is perpendicular to the D1 direction and the D2 direction. The D3 direction is the height direction of the capacitor module (1).

[0025] The D1 direction is the width direction for each of the first surface (21), the second surface (22), the fifth surface (25), and the sixth surface (26). The D2 direction is the length direction for the first to fourth surfaces (21 to 24). The D3 direction is the width direction for the third and fourth surfaces (23, 24), and also the length direction for the fifth and sixth surfaces (25, 26).

[0026] On the fifth surface (25), an injection hole (2h) for injecting an electrolyte into the interior of the receptacle (2) is formed. The injection hole (2h) is formed on the first surface (21) side rather than the second surface (22) of the receptacle (2). The injection hole (2h) is formed on the first surface (21) side rather than the external connection terminal (27). Also, in the state of FIG. 1, since the electrolyte has already been injected into the interior of the receptacle (2), the injection hole (2h) is in a blocked state. The injection hole (2h) may be temporarily blocked by inserting a removable plug into the injection hole (2h). Alternatively, the injection hole (2h) may be blocked with resin or metal so that the electrolyte cannot be re-injected unless the through hole is opened.

[0027] FIG. 3 is a cross-sectional view taken along the line III-III of FIG. 1. FIG. 3 is a cross-sectional view of a capacitor module (1). As shown in FIG. 3, the capacitor module (1) further comprises, in addition to the receiver (2) and the stacked electrode body (100), a plate-shaped member (201, 202), a tape material (301, 302), and an insulating sheet (500).

[0028] The plate-shaped member (201, 202), the tape material (301, 302), and the insulating sheet (500) are received in the receiver (2), just like the laminated electrode body (100). The plate-shaped member (201, 202), the tape material (301, 302), and the insulating sheet (500) are placed in the gap between the laminated electrode body (100) and the receiver (2).

[0029] The plate-shaped member (201, 202) is extended in the D2 direction. The plate-shaped member (201, 202) is disposed within the receptacle (2) such that the D3 direction is the direction of the thickness of the plate-shaped member (201). In this example, the plate-shaped member (202) has a shape symmetric to the plate-shaped member (201) with respect to the laminated electrode body (100). However, it is not limited thereto.

[0030] A plurality of through holes extending in the D3 direction are formed in the plate-shaped members (201, 202). In the plate-shaped members (201, 202), a plurality of through holes are formed in parallel in the D2 direction. Additionally, the capacitor module (1) does not necessarily have to be equipped with the plate-shaped members (201, 202).

[0031] The plate-shaped members (201, 202) are insulators. In this example, the plate-shaped members (201, 202) are formed of resin. In this example, the plate-shaped members (201, 202) are formed of an insulating material to prevent a short circuit between the positive electrode (120) and the negative electrode (110) of the laminated electrode body (100). Additionally, if sufficient insulation distance is secured between the plate-shaped members (201, 202) and the laminated electrode body (100), it is not necessary to make the plate-shaped members (201, 202) insulators.

[0032] As a material constituting the plate-shaped member (201, 202), for example, polypropylene is used. It is not limited thereto, and polyethylene, polyphenylene sulfide, polyether ether ketone, or PET (polyethylene terephthalate) may also be used.

[0033] A plate-shaped member (201) is placed on top of a stacked electrode body (100). Specifically, the plate-shaped member (201) is placed directly on top of the stacked electrode body (100). The plate-shaped member (201) is installed on the first surface (21) side of the receptor (2). The plate-shaped member (201) is installed in the direction of D31 among the D3 directions with respect to the stacked electrode body (100). Also, as described above, the direction of D31 is a vertical upward direction.

[0034] A plate-shaped member (202) is positioned below the stacked electrode body (100). Specifically, the plate-shaped member (202) is positioned directly below the stacked electrode body (100). The plate-shaped member (202) is installed on the second surface (22) side of the receptacle (2). The plate-shaped member (202) is installed in the direction of D32 among the D3 directions with respect to the stacked electrode body (100). Also, the direction of D32 is a vertical downward direction.

[0035] A plate-shaped member (201) is fixed to a laminated electrode body (100) by a tape material (301). A plate-shaped member (202) is fixed to a laminated electrode body (100) by a tape material (302). The tape materials (301, 302) extend in the D2 direction. The tape materials (301, 302) cover a portion of the laminated electrode body (100).

[0036] The laminated electrode body (100) has a periphery surface (180). The periphery surface (180) extends in the D2 direction. In FIG. 3, a cross-section of the periphery surface (180) is shown. The shape of the cross-section of the periphery surface (180) is a rectangular shape. The periphery surface (180) faces the receptor (2). The periphery surface (180) faces the inner circumference of the receptor (2). The periphery surface (180) faces the receptor (2) by interposing a member such as an insulating sheet (500).

[0037] The perimeter surface (180) has first and second sides (181, 182) on the D3 direction side and first and second sides (183, 184) on the D1 direction side. That is, the perimeter surface (180) has first and second sides (181, 182) in which the normal direction is the D3 direction and first and second sides (183, 184) in which the normal direction is the D1 direction.

[0038] The first side (181) is continuous with the first and second sides (183, 184). The first side (181) is the top surface. Likewise, the second side (182) is also continuous with the first and second sides (183, 184). The second side (182) is the bottom surface.

[0039] The first side (181) is parallel to the first surface (21) of the receptor (2). The second side (182) is parallel to the second surface (22). The first side (181) is a surface closer to the first surface (21) of the receptor (2) than the second side (182). The first main surface (183) is parallel to the third surface (23). The second main surface (184) is parallel to the fourth surface (24). The first main surface (183) is a surface closer to the third surface (23) than the second main surface (184). The width of the first and second sides (181, 182) in the D1 direction is narrower than the width of the first and second main surfaces (183, 184) in the D3 direction.

[0040] An insulating sheet (500) is provided between the periphery surface (180) of a laminated electrode body (100) and a receptacle (2), and also covers the periphery surface (180). The insulating sheet (500) insulates the laminated electrode body (100) and the receptacle (2). The insulating sheet (500) covers the laminated electrode body (100) so that the laminated electrode body (100) does not come into contact with the receptacle (2). The insulating sheet (500) is provided between the laminated electrode body (100) and the receptacle (2) (specifically, the inner surface of the receptacle) to prevent a short circuit of the laminated electrode body (100).

[0041] In detail, the insulating sheet (500) covers the plate-shaped members (201, 202). The insulating sheet (500) covers the plate-shaped member (201) with a tape material (301) interposed therebetween. Likewise, the insulating sheet (500) covers the plate-shaped member (202) with a tape material (302) interposed therebetween.

[0042] The insulating sheet (500) has its two ends welded together. With the plate-shaped member (201, 202) fixed to the laminated electrode body (100) by the tape material (301, 302), the insulating sheet (500) is wound around the tape material (301, 302), the plate-shaped member (201, 202), and the laminated electrode body (100). Then, by welding the two ends of the insulating sheet (500) together, the insulating sheet (500) shown in FIG. 3 is obtained. In the welding area (T1), the ends of the insulating sheet (500) are stacked on top of each other. The welding area (T1) extends in the direction of D2. Additionally, the insulating sheet (500) may be formed by connecting a plurality of insulating sheets.

[0043] In addition, polypropylene is used as a material constituting the insulating sheet (500), for example. It is not limited thereto, and polyethylene, polyphenylene sulfide, polyether ether ketone, nylon, or PET (polyethylene terephthalate) may be used.

[0044] FIG. 4 is a view of the stacked electrode body (100) of FIG. 3 in the direction of arrow B. As shown in FIG. 4, the stacked electrode body (100) additionally has a first cross section (185) and a second cross section (186) in addition to a first side (181), a second side (182), a first main surface (183), and a second main surface (184).

[0045] The first cross-section (185) is the surface on the fifth side (25) where the external connection terminal (27) (Fig. 1) on the negative side is provided. The second cross-section (186) is the surface on the sixth side (26) (Fig. 1) where the external connection terminal on the positive side is provided.

[0046] In the second side (182), each separator (130) is welded along the length of the D1 direction of the stacked electrode body (100). With this configuration, the movement of each separator (130) in the D3 direction within the stacked electrode body (100) is restricted. Therefore, the stacked electrode body (100) can prevent misalignment of the position of each separator (130). In addition, the stacked electrode body (100) can suppress the amount of protrusion of each separator (130) from the outer edge between the negative electrode (110) and the positive electrode (120). Thus, the stacked electrode body (100) can suppress the space that does not contribute to charging and discharging.

[0047] Specifically, each separator (130) is welded to each other along the length of the D1 direction of the stacked electrode body (100) at each of a plurality of locations separated in the D2 direction. In this embodiment, the separators (130) are directly welded to each other. In the stacked electrode body (100), there are a plurality of welded portions (U1) formed by welding of each separator (130).

[0048] The length in the D1 direction of each weld (U1) is the same. The length in the D1 direction is approximately the same as the length in the D1 direction of the laminated electrode body (100). The length in the D2 direction of each weld (U1) is the same. In this example, each weld (U1) is formed evenly in the D2 direction. The distance between adjacent welds (U1) is the same. Each weld (U1) is typically formed by contacting a heat soldering iron to each separator (130).

[0049] Each welded portion (U1) covers a portion of the positive electrode (120) and a portion of the negative electrode (110) in the D1 direction when viewing the laminated electrode body (100) from the second side (182). Each welded portion (U1) may be in contact with the edge portion of the positive electrode (120) and the edge portion of the negative electrode (110).

[0050] A plurality of separators (130) are fixed to each other by each welded portion (U1). On the second side (182), the relative position of each separator (130) is fixed. Therefore, movement of each separator (130) in the D3 direction within the stacked electrode body (100) is restricted. In this way, the capacitor module (1) prevents misalignment of the position of each separator (130). Additionally, the welded portion can be made smaller by welding the separators (130) together over the entire surface of the second side (182).

[0051] As described above, since the separators (130) are directly welded to each other, each separator (130) can be fixed in position without using other components. In addition, in the capacitor module (1), as described above, since each welded portion (U1) is formed evenly in the D2 direction, the effect of preventing misalignment of each separator (130) is higher compared to the case where they are not formed evenly.

[0052] Each positive electrode (120) and each negative electrode (110) are interlocked with each other by separators (130). Therefore, movement in the D3 direction between each positive electrode (120) and each negative electrode (110) with respect to each separator (130) can be restricted. Specifically, positional misalignment in the D31 direction between each positive electrode (120) and each negative electrode (110) with respect to each separator (130) can also be suppressed.

[0053] Additionally, the capacitor module (1) has the following advantages when injecting the electrolyte into the receiver (2) from the injection hole (2h) (Fig. 1). When injecting the electrolyte from the injection hole (2h) during the manufacture of the capacitor module (1), the capacitor module (1) is maintained in such a way that the D2 direction is approximately vertical and the fifth side (25) is positioned higher than the sixth side (26). Due to the gravity of the electrolyte, the electrolyte flows from the fifth side (25) to the sixth side (26). Furthermore, since the electrolyte has a certain degree of viscosity, it falls into the receiver (2) at a relatively slow speed. Accordingly, the electrolyte can be impregnated into the laminated electrode body (100).

[0054] In this regard, on the second side (182) of the laminated electrode body (100), as described above, the separators (130) are not welded to each other between the welded portions (U1). Therefore, when the electrolyte falls into the receptacle (2) or when the fallen electrolyte rises, the electrolyte can be impregnated into the interior of the laminated electrode body (100) from the non-welded portions (hereinafter also referred to as "non-welded portions") of the second side (182). In addition, since there is no welded portion (U1) on the first side (181), when the electrolyte falls into the receptacle (2), the electrolyte can be impregnated into the interior of the laminated electrode body (100) from the entire first side (181).

[0055] In this way, by welding the separators (130) together at each of the multiple locations on the second side (182) along the length of the D1 direction of the laminated electrode body (100), it becomes easier to impregnate the electrolyte into the interior of the laminated electrode body (100) than when the entire second side (182) is welded.

[0056] However, as described above, the injection hole (2h) is formed on the first side (21) side rather than the second side (22) of the receptacle (2). In the D3 direction, the injection hole (2h) is located on the first side (181) side rather than the second side (182) of the laminated electrode body (100). That is, the first side (181), where the weld portion (U1) is not formed, is located closer to the injection hole (2h) than the second side (22), where the weld portion (U1) is formed.

[0057] When the electrolyte is flowed in the D2 direction by gravity through the injection hole (2h), since the injection hole (2h) is closer to the first side (181) than to the second side (182), the electrolyte is more likely to pass through the first side (181) than the second side (182). Although the electrolyte is obstructed from flowing into the laminated electrode body (100) by the welded portion (U1), since the welded portion (U1) is only on the second side (182) side, the electrolyte is more likely to be impregnated into the laminated electrode body (100) compared to when it is on the first side (181) side.

[0058] Therefore, according to this configuration, compared to the case where the injection hole (2h) is formed on the second side (182) side rather than the first side (181), the electrolyte can be efficiently impregnated into the interior of the laminated electrode body (100) when injected into the electrolyte receiver (2).

[0059] In addition, in the first side (181) (Fig. 3), multiple welded portions (U1) may be formed, just as in the second side (182). In this case, positional misalignment of each separator (130) can be prevented more effectively than when each separator (130) is welded in the second side (182). Furthermore, with this configuration, positional misalignment in the direction of D32 between each positive electrode (120) and each negative electrode (110) with respect to each separator (130) can also be suppressed. Accordingly, with this configuration, positional misalignment in the direction of D3 between each positive electrode (120) and each negative electrode (110) with respect to each separator (130) can be suppressed.

[0060] The above is not limited to the above, and the weld portion (U1) may be formed only on the first side (181) among the first side (181) and the second side (182). Each separator (130) may be welded along the length of the D1 direction of the laminated electrode body (100) on at least one of the first side (181) and the second side (182).

[0061] In this example, the injection hole (2h) is formed on the first surface (21) side relative to the external connection terminal (27), but is not limited thereto. The injection hole (2h) may be formed on the second surface (22) side relative to the external connection terminal (27). The injection hole (2h) may be formed on the third surface (23) side relative to the external connection terminal (27). The injection hole (2h) may be formed on the fourth surface (24) side relative to the external connection terminal (27).

[0062] In addition, in this example, a configuration in which the injection hole (2h) is formed on the fifth surface (25) has been described as an example, but it is not limited thereto. For example, the injection hole (2h) may be formed on the sixth surface (26). The injection hole (2h) may be formed on the first surface (21) or the second surface (22). When the injection hole (2h) is formed on the first surface (21) or the second surface (22), from the perspective of injection properties, it is preferable that the injection hole (2h) be formed on the end side (the fifth surface (25) side or the sixth surface (26) side) rather than the center side in the longitudinal direction of the receptacle (2). The injection hole (2h) may be formed on the third surface (23) or the fourth surface (24). The location of formation of the injection hole (2h) is not particularly limited.

[0063] Summary

[0064] As described above, the capacitor module (1) comprises a stacked electrode body (100) impregnated with an electrolyte and a receiver (2) that accommodates the stacked electrode body (100). As shown in FIG. 2, the stacked electrode body (100) has a positive electrode (120), a separator (130), and a negative electrode (110) alternately stacked in the direction of D1 and also extends in the direction of D2 which is perpendicular to the direction of D1.

[0065] As shown in FIG. 3, the stacked electrode body (100) has a periphery surface (180) that extends in the D2 direction and also faces the receptor (2) (specifically, the inner surface of the receptor). The length of each separator (130) in the D3 direction, which is perpendicular to the D1 and D2 directions, is longer than the length of each positive electrode (120) and each negative electrode (110) in the D3 direction. As shown in FIG. 3, the periphery surface (180) has first and second main surfaces (183, 184) on the D1 direction side and first and second side surfaces (181, 182) on the D3 direction side, each of which is continuous with the first and second main surfaces (183, 184).

[0066] As shown in FIG. 3, the width in the D1 direction of the first and second sides (181, 182) is narrower than the width in the D3 direction of the first and second main sides (183, 184). In the example of FIG. 4, each separator (130) is welded along the length in the D1 direction of the laminated electrode body (100) on the second side (182).

[0067] In detail, as shown in FIG. 4, each separator (130) is welded to each other along the length of the D1 direction of the stacked electrode body (100) at each of a plurality of locations separated in the D2 direction.

[0068] More specifically, as shown in FIG. 1, a liquid injection hole (2h) for injecting an electrolyte into the capacitor module (1) is formed in the receptacle (2). As shown in FIG. 1, the liquid injection hole (2h) is formed at the end of the receptacle (2) in the D2 direction and is also closer to the first side (181) than to the second side (182). As shown in FIG. 4, each separator (130) is welded only on the second side (182) among the first side (181) and the second side (182). Furthermore, it is not limited thereto, and each separator (130) may be welded along the length in the D1 direction of the stacked electrode body (100) on at least one of the first side (181) and the second side (182).

[0069] <Variation Example>

[0070] Below, a modified example of the laminated electrode body (100) will be described. In detail, a modified example of the formation location of the welded portion of the separator (130) will be described.

[0071] (1) First variant

[0072] FIG. 5 is a figure showing a first modified example of a stacked electrode body (100). As shown in FIG. 5, in the stacked electrode body (100A), each separator (130) is welded along the length in the D1 direction of the stacked electrode body (100A) on the second side (182), just like in the stacked electrode body (100). Specifically, each separator (130) is welded to each other along the length in the D1 direction of the stacked electrode body (100A) at each of a plurality of locations separated in the D2 direction. The separators (130) are directly welded to each other. In the stacked electrode body (100A), there are a plurality of welded portions (U1) formed by welding between each separator (130).

[0073] In the laminated electrode body (100A), the weld portion (U1) is located in the center of the second side (182) in the D2 direction. In the laminated electrode body (100A), the weld portion (U1) is not located at the end of the second side (182) in the D2 direction.

[0074] With a laminated electrode body (100A) having such a configuration, the same effect as with the laminated electrode body (100) can be obtained. In addition, with the laminated electrode body (100A), it is easier to impregnate the electrolyte into the laminated electrode body than with the laminated electrode body (100). In particular, with the laminated electrode body (100A), it is easier to impregnate the electrolyte from both ends in the D2 direction of the second side (182) than with the laminated electrode body (100).

[0075] (2) Second variant

[0076] FIG. 6 is a figure showing a second modified example of a stacked electrode body (100). As shown in FIG. 6, in the stacked electrode body (100B), each separator (130) is welded along the length in the D1 direction of the stacked electrode body (100B) on the second side (182), just like in the stacked electrode body (100). Specifically, each separator (130) is welded to each other along the length in the D1 direction of the stacked electrode body (100B) at each of a plurality of locations separated in the D2 direction. The separators (130) are directly welded to each other. In the stacked electrode body (100B), there are a plurality of welded portions (U1) formed by welding between each separator (130).

[0077] In the laminated electrode body (100B), the weld portion (U1) is located at the end of the second side (182) in the D2 direction. In the laminated electrode body (100B), the weld portion (U1) is not located in the central part in the D2 direction.

[0078] With a laminated electrode body (100B) having such a configuration, the same effect as with the laminated electrode body (100) can be obtained. In addition, with the laminated electrode body (100B), it is easier to impregnate the electrolyte into the laminated electrode body than with the laminated electrode body (100). In particular, with the laminated electrode body (100B), it is easier to impregnate the electrolyte from the central part in the D2 direction of the second side (182) than with the laminated electrode body (100).

[0079] (3) Third variant

[0080] FIG. 7 is a diagram showing a third modified example of a stacked electrode body (100). As shown in FIG. 7, in the stacked electrode body (100C), each separator (130) is welded along the length in the D1 direction of the stacked electrode body (100C) on the second side (182), just like in the stacked electrode body (100). Specifically, each separator (130) is welded to each other along the length in the D1 direction of the stacked electrode body (100C) at each of a plurality of locations separated in the D2 direction. The separators (130) are directly welded to each other.

[0081] In the laminated electrode body (100C), there are multiple welded portions (U2, U3, U4, U5) formed by welding between each separator (130). From the second cross section (186) side toward the first cross section (185), the welded portion (U2), the welded portion (U3), the welded portion (U4), and the welded portion (U5) exist in this order.

[0082] The length in the D1 direction of the weld section (U2, U3, U4, U5) is the same as the length in the D1 direction of the weld section (U1). The length (width) in the D2 direction of the weld section (U2, U3, U4, U5) is shorter in this order. The weld section (U2, U3, U4, U5) has a shorter length (width) in the D2 direction the further it is from the fifth surface (25) (the surface on the side of the first cross section (185)) of the receiver (2). That is, the weld section (U2, U3, U4, U5) has a shorter length (width) in the D2 direction the further it is from the injection hole (2h).

[0083] However, when the electrolyte is injected into the receiver (2), most of the electrolyte is not immediately impregnated into the laminated electrode body (100C), but first passes around the laminated electrode body (100C) and moves (falls) from the first cross section (185) side to the side opposite to the injection hole (2h) (the second cross section (186) side). After that, the electrolyte moves (rises) within the laminated electrode body (100C) from the side opposite to the injection hole (2h) (the second cross section (186) side) toward the first cross section (185) side (the injection hole (2h) side) by capillary action. Through this action, the electrolyte can be supplied throughout the entire interior of the laminated electrode body (100C).

[0084] In addition, as time passes and the amount of electrolyte injected increases, the electrolyte can be supplied into the laminated electrode body (100C) from the surroundings. At this time, since the length (width) in the D2 direction is shorter the further the welded part is from the injection hole (2h), the electrolyte can be efficiently impregnated into the interior of the laminated electrode body (100C) from the part of the second side (182) of the laminated electrode body (100C) that is far from the injection hole (2h) (specifically, the non-welded part).

[0085] (4) 4th variant

[0086] FIG. 8 is a diagram showing a fourth modified example of a stacked electrode body (100). As shown in FIG. 8, in the stacked electrode body (100D), each separator (130) is welded along the length of the D1 direction of the stacked electrode body (100D) on the second side (182), just like in the stacked electrode body (100). Specifically, each separator (130) is welded to each other along the length of the D1 direction of the stacked electrode body (100D) at each of a plurality of locations separated in the D2 direction. The separators (130) are directly welded to each other.

[0087] In the laminated electrode body (100D), as in the laminated electrode body (100C), there are multiple welded portions (U2, U3, U4, U5) formed by welding between each separator (130). In the laminated electrode body (100D), unlike the laminated electrode body (100C), the welded portion (U5), the welded portion (U4), the welded portion (U3), and the welded portion (U2) exist in this order from the second cross-section (186) side toward the first cross-section (185).

[0088] In the laminated electrode body (100D), the weld portions (U2, U3, U4, U5) have a shorter length (width) in the D2 direction the closer the weld portion is to the fifth surface (25) (the surface on the first cross-section (185) side) of the receiver (2). That is, the weld portions (U2, U3, U4, U5) have a shorter length (width) in the D2 direction the closer the weld portion is to the injection hole (2h).

[0089] With a laminated electrode body (100D) of this configuration, the same effect as that of a laminated electrode body (100) can be obtained. In addition, when injecting into the electrolyte receiver (2), the electrolyte moving (falling) from the first cross-section (185) side to the opposite side of the injection hole (2h) can be efficiently impregnated into the laminated electrode body (100D).

[0090] (5) Fifth variant

[0091] FIG. 9 is a figure showing a fifth modified example of a stacked electrode body (100). As shown in FIG. 9, in the stacked electrode body (100E), each separator (130) is welded along the length in the D1 direction of the stacked electrode body (100E) on the second side (182), just like in the stacked electrode body (100). Specifically, each separator (130) is welded to each other along a length shorter than the length (thickness) in the D1 direction of the stacked electrode body (100E) at each of a plurality of locations separated in the D2 direction. The separators (130) are directly welded to each other.

[0092] In the laminated electrode body (100E), there are multiple welded portions (U6) and multiple welded portions (U7) formed by welding between each separator (130). In the laminated electrode body (100E), the welded portions (U6) and welded portions (U7) are formed alternately in the D2 direction. When viewing the laminated electrode body (100E) in the direction of, for example, D21, the welded portions (U6) and welded portions (U7) partially overlap in the D1 direction. Due to this overlap, all separators (130) are fixed in position.

[0093] In detail, each weld (U6) is formed at equal intervals in the D2 direction. Each weld (U6) is formed from the second main surface (184) toward the first main surface (183) in the D1 direction. Each weld (U6) does not reach the first main surface (183). Each weld (U6) extends from the second main surface (184) to a position between the middle position of the second side (182) in the D1 direction and the position of the first main surface (183).

[0094] Likewise, each weld (U7) is formed at equal intervals in the D2 direction. Each weld (U7) is formed from the first main surface (183) toward the second main surface (184) in the D1 direction. Each weld (U7) does not reach the second main surface (184). Each weld (U7) extends from the first main surface (183) to a position between the intermediate position of the second side (182) in the D1 direction and the position of the second main surface (184).

[0095] With a stacked electrode body (100E) of such a configuration, the same effect as that of a stacked electrode body (100) can be obtained.

[0096] (6) 6th variant

[0097] FIG. 10 is a figure showing a sixth modified example of a stacked electrode body (100). As shown in FIG. 10, in the stacked electrode body (100F), each separator (130) is welded along the length of the D1 direction of the stacked electrode body (100F) on the second side (182), just like in the stacked electrode body (100). The separators (130) are directly welded to each other.

[0098] In the laminated electrode body (100F), one welded portion (U8) is formed. When viewing the second side (182) in the direction of D31, the welded portion (U8) has an X-shape. In the welded portion (U8), at both ends of the second side (182) in the direction of D2, the separators (130) are welded to each other in two areas separated in the direction of D1. In the central part of the second side (182) in the direction of D2, the separators (130) are welded to each other in only one area in the direction of D1.

[0099] With a laminated electrode body (100C) of this configuration, the same effect as that of a laminated electrode body (100) can be obtained. In addition, it becomes easy to weld all separators (130) in a single welding process.

[0100] [Embodiment 2]

[0101] In this embodiment, differences from the capacitor module (1) related to embodiment 1 are explained.

[0102] FIG. 11 is a cross-sectional view of a capacitor module (1A) related to the present embodiment. As shown in FIG. 11, the capacitor module (1A) has a receptacle (2), a stacked electrode body (100), a plate-shaped member (201, 202), a tape material (301, 302), an insulating sheet (500), and a plate-shaped member (400).

[0103] The capacitor module (1A) differs from the capacitor module (1) of Embodiment 1 in that it is equipped with a plate-shaped member (400). The plate-shaped member (400) is located between the laminated electrode body (100) and the plate-shaped member (202). The plate-shaped member (400) extends not only in the D1 direction but also in the D2 direction. The plate-shaped member (400) is typically made of a resin material.

[0104] In the capacitor module (1A), just like in the capacitor module (1), each separator (130) is welded along the length of the D1 direction of the stacked electrode body (100) on the second side (182). Specifically, in the capacitor module (1A), each separator (130) of the stacked electrode body (100) is welded to the plate-shaped member (400). In this way, in the capacitor module (1A), each separator (130) is welded to each other through the plate-shaped member (400).

[0105] The plate-shaped member (400) is preferably composed of a plurality of element members spaced apart in the D2 direction. Each element member can be installed, for example, at a position corresponding to the weldment (U1) of FIG. 4, and each separator (130) can be heat-welded to each element member. The arrangement of each element member is not limited thereto and may be installed at a position corresponding to each weldment in FIG. 5 to FIG. 11.

[0106] With a capacitor module (1A) of this configuration, the same effect as that of the capacitor module (1) of Embodiment 1 can be obtained. In addition, in the capacitor module (1A), since a plate-shaped member (400) is used, it is easier to fix the position of the separator (130) compared to the configuration in which the separator (130) is directly welded together as in Embodiment 1.

[0107] The capacitor module (1A) is equipped with a stacked electrode body (100), similar to the capacitor module (1) associated with embodiment 1. Thus, as described in embodiment 1, in this embodiment, it is possible to prevent misalignment of each separator (130) and to suppress space that does not contribute to charging and discharging.

[0108] Additionally, a plate-shaped member (400) may be positioned between the stacked electrode body (100) and the plate-shaped member (201). A plate-shaped member (400) may be formed between the stacked electrode body (100) and the plate-shaped member (202), and between the stacked electrode body (100) and the plate-shaped member (201), respectively.

[0109] 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 defined by the claims, and all modifications within the meaning and scope equivalent to the claims are intended to be included.

Claims

Claim 1 A laminated electrode body comprising a plurality of electrodes and a plurality of separators, wherein each of the electrodes and each of the separators are alternately laminated in a first direction, wherein the laminated electrode body extends in a second direction perpendicular to the first direction and further comprises a periphery surface extending in the second direction, wherein the length of each separator in a third direction perpendicular to the first direction and the second direction is longer than the length of each electrode in the third direction, and wherein the periphery surface has first and second main surfaces on the first direction side and first and second side surfaces on the third direction side, each of which is continuous with the first and second main surfaces, and wherein each of the separators is welded to each other along the length of the first direction of the laminated electrode body on at least one of the first side surface and the second side surface. Claim 2 In claim 1, each of the separators is welded to each other along the length of the first direction of the laminated electrode at each of the plurality of locations separated in the second direction. Claim 3 A capacitor module comprising a laminated electrode body described in claim 1 and a receptacle for receiving the laminated electrode body, wherein the receptacle has an injection hole formed therein for injecting an electrolyte into the receptacle, wherein the injection hole is formed at the end of the receptacle on the second direction side and is closer to the first side than the second side, and wherein each separator is welded only on the second side among the first side and the second side. Claim 4 In claim 3, each of the separators is welded to each other along the length of the first direction of the laminated electrode body at each of the plurality of locations separated in the second direction, and the length of each of the plurality of locations in the second direction is shorter the further the location is from the injection hole, forming a capacitor module.

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