JP2018120830A - Power storage element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power storage element that suppresses oscillation of an electrode body and a current collector in a case and suppresses damage to the electrode body and the current collector.SOLUTION: A power storage element includes a case 3, an external terminal disposed outside the case 3, an electrode body disposed inside the case 3, a current collector 5 having a connecting portion 52 connected to the electrode body in a state of being superimposed on the outer surface of the electrode body and connecting the electrode body and the external terminal inside the case 3, and a spacer disposed between the case 3 and the current collector 5 to regulate the movement of the electrode body with respect to the case 3, and one of the connecting portion 52 of the current collector 5 and the spacer has a convex portion protruding in the overlapping direction of the connecting portion 52 of the current collector 5 with respect to the electrode body, and the other one of the connecting portion 52 of the current collector 5 and the spacer has a concave portion or a hole including a peripheral edge surrounding the convex portion.SELECTED DRAWING: Figure 10

Description

  The present invention relates to a power storage device including a spacer that restricts movement of an electrode body relative to a case.

  Conventionally, a battery including an insulating cover disposed between an outer can, a positive electrode lead, and a negative electrode lead is known (see Patent Document 1). The battery includes an outer can, a wound electrode group housed in the outer can, a positive electrode lead and a negative electrode lead connected to the wound electrode group, an opening of the outer can, and a positive electrode terminal and a negative electrode terminal. A lid having a positive electrode insulating cover disposed between the positive electrode lead and the outer can, and a negative electrode insulating cover disposed between the negative electrode lead and the outer can.

  The wound electrode group has a positive electrode current collecting tab at one end in the winding axis direction and a negative electrode current collecting tab at the other end. The wound electrode group is accommodated in the outer can so as to be directed in a direction perpendicular to the winding axis.

  The positive electrode lead is a connection plate connected to the positive electrode terminal, and a first and second pinching portion that branches into two from the connection plate and extends in a direction perpendicular to the winding axis to the wound electrode group. Two clamping strips. The first and second strips of the positive electrode lead sandwich the positive electrode current collecting tab from a direction perpendicular to the winding axis, and are joined to the positive electrode current collecting tab by welding.

  The negative electrode lead is a connection plate connected to the negative electrode terminal, and a first and second clamping portions that branch into two from the connection plate and extend in a direction perpendicular to the winding axis to the wound electrode group. Two clamping strips. The first and second strips of the negative electrode lead sandwich the negative electrode current collecting tab from a direction perpendicular to the winding axis, and are joined to the negative electrode current collecting tab by welding.

  The positive and negative insulating covers are respectively fitted to both ends including the current collecting tabs of the wound electrode group sandwiched between the first and second sandwiching strips of the positive and negative leads, and the sandwiching strips and the current collecting tabs are connected to each other. cover.

  As described above, the insulating cover is arranged to suppress the swing of the wound electrode group inside the battery. Thereby, it can prevent that a current collection tab deform | transforms or is damaged, and joining with a lead is removed.

  However, in the battery, since the insulating cover is arranged along the strip of the lead and is not restrained in the extending direction of the strip, the lead and the wound electrode group may be allowed to move in this direction. For this reason, in the said battery, damage to the lead | read | reed and winding electrode group in a vibration environment cannot fully be prevented.

JP 2012-227110 A

  Therefore, an object of the present embodiment is to provide a storage element that suppresses the swing of the electrode body and the current collector inside the case and suppresses the damage of the electrode body and the current collector.

The electricity storage device of this embodiment is
Case and
An external terminal disposed outside the case;
An electrode body disposed inside the case;
A current collector having a connection portion connected to the electrode body in a state of being superimposed on the outer surface of the electrode body, and connecting the electrode body and the external terminal;
A spacer having an insulating property and disposed between the case and the current collector and restricted in movement by the case, and
Either one of the connection part or the spacer of the current collector has a convex part protruding in the overlapping direction of the connection part of the current collector with respect to the electrode body,
Either the connection part or the spacer of the current collector has a recess or a hole including a peripheral edge surrounding the protrusion.

  According to such a configuration, the spacer whose movement is restricted by the case and the current collector (specifically, the connecting portion) connected to the electrode body surround the protruding portion protruding in the overlapping direction and the protruding portion. Therefore, the relative movement of the spacer and the current collector in the direction orthogonal to the overlapping direction can be suppressed. Accordingly, the electrode body can be prevented from swinging in the direction orthogonal to the overlapping direction via the connection portion and the spacer, and damage to the electrode body and the current collector due to the swing can be suppressed.

In the storage element,
The connecting portion includes a first concave portion facing the electrode body and a second convex portion facing the first concave portion, or a first convex portion facing the electrode body and the first convex portion. A second recess in a front-back relationship with
The first concave portion or the first convex portion of the connection portion may be unevenly fitted with the electrode body, and the second convex portion or the second concave portion of the connection portion may be unevenly fitted with the spacer. .

  According to such a configuration, since the electrode body and the spacer are respectively concavo-convexly fitted to the connection portion at the same position (front and back positions) of the connection portion, the portion where the connection portion and the electrode body are concavo-convexly fitted The relative movement of the spacer in the direction perpendicular to the fitting direction with respect to the electrode body and the current collector can be suppressed without separately forming the portions where the connection portion and the spacer are unevenly fitted.

Further, in the power storage element,
The electrode body has a main body in which an active material layer is disposed, and a connected portion that is adjacent to the main body and to which the connecting portion of the current collector is connected,
The fitting part where the spacer, the connection part, and the electrode body are unevenly fitted may be located inside the main body as seen from the direction from the connected part toward the main body.

  According to such a configuration, the fitting portion (the portion where the spacer, the connecting portion, and the electrode body are fitted to the concave and convex portions) is located inside the main body when viewed from the direction (predetermined direction) from the connected portion toward the main body. Therefore, when the case is disposed close to the main body of the electrode body in a direction orthogonal to the predetermined direction, the fitting portion does not get in the way.

In the storage element,
The current collector includes a pair of connection portions that sandwich the electrode body,
The spacer includes a pair of overlapping portions that overlap the pair of connection portions in a direction in which the pair of connection portions are sandwiched,
Each of the pair of connection portions has the second concave portion at a position facing the overlapping portion,
Each of the pair of overlapping portions may be concavo-convexly fitted with the second concave portion of the facing connection portion.

  According to such a configuration, since the pair of connecting portions that sandwich the electrode body are located between the pair of overlapping portions in the sandwiching direction (that is, the overlapping direction of the electrode body and the connecting portion), the overlapping direction The movement of the pair of connection parts to the is restricted, and thereby the movement (swing) of the electrode body in the overlapping direction is also suppressed. That is, the electrode body extends in a direction perpendicular to the overlapping direction (the sandwiching direction) of the electrode body by fitting the convex portion of the spacer and the current collector with the concave portion or the hole including the peripheral edge surrounding the convex portion. Since the swinging is suppressed, the electrode body is positioned between the pair of overlapping portions via the pair of connecting portions and the swinging of the electrode body in the overlapping direction is also suppressed, so that the movement in any direction ( Oscillation) is also suppressed.

Further, in the power storage element,
The electrode body has a wound electrode,
The spacer may be disposed at a position corresponding to each end portion in the winding central axis direction of the electrode body.

  According to this configuration, the spacer and the current collector (specifically, the connecting portion) include the convex portion and the concave portion including the peripheral edge surrounding the convex portion at positions corresponding to the respective end portions in the winding central axis direction of the electrode body. Or since it fits with the hole, the rocking | fluctuation to the direction orthogonal to the said superimposition direction of an electrode body is suppressed more reliably.

  As described above, according to the present embodiment, it is possible to provide a power storage device that suppresses the swing of the electrode body and the current collector in the case and suppresses damage to the electrode body and the current collector.

FIG. 1 is a perspective view of a power storage device according to this embodiment. 2 is a cross-sectional view taken along the line II-II in FIG. FIG. 3 is an exploded perspective view of the power storage element. FIG. 4 is a diagram for explaining an electrode body of the electricity storage element. FIG. 5 is a perspective view of the electricity storage device with a case body, an insulating member, and a spacer removed. FIG. 6 is an enlarged cross-sectional view for explaining a fitting site. FIG. 7 is a diagram for explaining caulking joining. FIG. 8 is a diagram for explaining caulking joining. FIG. 9 is a perspective view of a pair of clip members. FIG. 10 is a partially enlarged cross-sectional view of the position XX in FIG. FIG. 11 is a perspective view of the spacer. 12 is a cross-sectional view at the position XII-XII in FIG. FIG. 13 is a schematic diagram for explaining the positional relationship between the main body of the electrode body and the fitting portion viewed from the X-axis direction. FIG. 14 is a view for explaining a method of arranging the overlapping portion of the spacer outside the connecting portion of the current collector. FIG. 15 is a schematic diagram for explaining a spacer according to another embodiment. FIG. 16 is a schematic diagram for explaining a spacer according to another embodiment. FIG. 17 is a schematic diagram for explaining a spacer according to another embodiment. FIG. 18 is a schematic diagram for explaining a spacer and a fitting portion according to another embodiment. FIG. 19 is a schematic diagram for explaining a spacer and a fitting portion according to another embodiment. FIG. 20 is a schematic diagram for explaining a connection portion between a spacer and a current collector according to another embodiment. FIG. 21 is a schematic diagram of a power storage device including the power storage element of the embodiment.

  Hereinafter, an embodiment of a power storage device according to the present invention will be described with reference to FIGS. Examples of the power storage element include a primary battery, a secondary battery, and a capacitor. In the present embodiment, a chargeable / dischargeable secondary battery will be described as an example of a power storage element. In addition, the name of each component (each component) of this embodiment is a thing in this embodiment, and may differ from the name of each component (each component) in background art.

  The electricity storage device of this embodiment is a nonaqueous electrolyte secondary battery. More specifically, the power storage element is a lithium ion secondary battery that utilizes electron transfer that occurs as lithium ions move. This type of power storage element supplies electrical energy. One or a plurality of power storage elements are used. Specifically, the storage element is used singly when the required output and the required voltage are small. On the other hand, when at least one of a required output and a required voltage is large, the power storage element is used in a power storage device in combination with another power storage element. In the power storage device, a power storage element used in the power storage device supplies electric energy.

  As shown in FIGS. 1 to 5, the power storage element includes an electrode body 2, a case 3 in which the electrode body 2 is disposed, an external terminal 4 in which at least a part is disposed outside the case 3, and a case 3, a current collector 5 that connects the electrode body 2 and the external terminal 4 inside, and a spacer 8 that is disposed between the case 3 and the current collector 5. In addition, the power storage element 1 includes an insulating member 6 that covers the electrode body 2 and the current collector 5 inside the case 3. In the electricity storage device 1 of the present embodiment, the electrode body 2, the current collector 5, and the spacer 8 are unevenly fitted to each other. In FIG. 3, the electrode body 2 and the current collector 5 are shown in a state before the concave and convex fitting.

  The electrode body 2 has wound electrodes (a positive electrode 23 and a negative electrode 24). The electrode body 2 includes a main body 20 on which an active material layer (a positive electrode active material layer 232 and a negative electrode active material layer 242) is disposed, and a connected portion 26 adjacent to the main body 20 and connected to the current collector 5. (See FIG. 4). Details are as follows.

  The electrode body 2 has electrodes (positive electrode 23 and negative electrode 24) wound in a stacked state. Specifically, the electrode body 2 includes a winding core 21, and a stacked body 22 in which a positive electrode 23 and a negative electrode 24 are stacked in a state of being insulated from each other and wound around the winding core 21. As the lithium ions move between the positive electrode 23 and the negative electrode 24 in the electrode body 2, the power storage device 1 is charged and discharged.

  The winding core 21 is usually formed of an insulating material. The core 21 of this embodiment is a flat cylinder shape. The winding core 21 is formed by winding a sheet having flexibility or thermoplasticity.

  The positive electrode 23 includes a strip-shaped metal foil 231 and a positive electrode active material layer 232 stacked on the metal foil 231. This positive electrode active material layer 232 is overlaid on the metal foil 231 in a state where one end portion (uncovered portion) in the width direction of the metal foil 231 is exposed. The metal foil 231 of this embodiment is, for example, an aluminum foil.

  The negative electrode 24 includes a strip-shaped metal foil 241 and a negative electrode active material layer 242 stacked on the metal foil 241. The negative electrode active material layer 242 is formed in a state in which the other edge in the width direction of the metal foil 241 (on the side opposite to the non-covered portion of the metal foil 231 of the positive electrode 23) (uncovered portion) is exposed. 241. The metal foil 241 of this embodiment is, for example, a copper foil.

  In the electrode body 2 of the present embodiment, the positive electrode 23 and the negative electrode 24 configured as described above are wound in a state where they are insulated by the separator 25. That is, in the electrode body 2 of this embodiment, the laminated body 22 of the positive electrode 23, the negative electrode 24, and the separator 25 is wound.

  The separator 25 is an insulating member and is disposed between the positive electrode 23 and the negative electrode 24. Thereby, in the electrode body 2 (specifically, the laminated body 22), the positive electrode 23 and the negative electrode 24 are insulated from each other. The separator 25 holds the electrolytic solution in the case 3. Thereby, at the time of charging / discharging of the electrical storage element 1, a lithium ion can move between the positive electrode 23 and the negative electrode 24 which are alternately laminated on both sides of the separator 25. This separator 25 is comprised by porous membranes, such as polyethylene, a polypropylene, a cellulose, polyamide, for example.

  The dimension of the separator 25 in the width direction is larger than the width of the negative electrode active material layer 242. The separator 25 is disposed between the positive electrode 23 and the negative electrode 24 that are stacked in a state where the positive electrode active material layer 232 and the negative electrode active material layer 242 are displaced in the width direction so as to overlap in the thickness direction (stacking direction). The At this time, the uncoated portion of the positive electrode 23 and the uncoated portion of the negative electrode 24 do not overlap. That is, the uncovered portion of the positive electrode 23 protrudes from the region where the positive electrode 23 and the negative electrode 24 overlap in the width direction (direction orthogonal to the stacking direction), and the non-covered portion of the negative electrode 24 is between the positive electrode 23 and the negative electrode 24. It protrudes in the width direction (direction opposite to the protruding direction of the non-covered portion of the positive electrode 23) from the overlapping region. The electrode body 2 is formed by winding the positive electrode 23, the negative electrode 24, and the separator 25 (that is, the stacked body 22) stacked in such a state.

  In the electrode body 2 of the present embodiment, the electrode body 2 includes a portion where the positive electrode active material layer 232 of the positive electrode 23 is disposed, a portion where the negative electrode active material layer 242 of the negative electrode 24 is disposed, and a portion where the separator 25 is laminated. The main body 20 in FIG. Further, the connected portion 26 in the electrode body 2 is configured by a portion where only the non-covered portion of the positive electrode 23 or the non-covered portion of the negative electrode 24 is laminated.

  The connected portion 26 is a portion that is electrically connected to the current collector 5 in the electrode body 2. The connected portion 26 of the present embodiment has two hollow portions 27 (see FIGS. 3 and 4) sandwiched between the wound positive electrode 23, negative electrode 24, and separator 25, as viewed from the winding central axis C direction. It is divided into parts (divided connected parts) 261.

  The connected portion 26 configured as described above is provided at each pole of the electrode body 2. That is, the connected portion 26 in which only the non-covered portion of the positive electrode 23 is stacked constitutes the connected portion of the positive electrode in the electrode body 2, and the connected portion 26 in which only the non-covered portion of the negative electrode 24 is stacked is the electrode body 2. The negative electrode connected portion in FIG.

  The case 3 includes a case main body 31 having an opening and a cover plate 32 that closes (closes) the opening of the case main body 31. The case 3 houses the electrolytic solution in the internal space together with the electrode body 2 and the current collector 5. Case 3 is formed of a metal having resistance to the electrolytic solution. The case 3 of the present embodiment is formed of an aluminum metal material such as aluminum or an aluminum alloy, for example.

The electrolytic solution is a non-aqueous electrolytic solution. The electrolytic solution is obtained by dissolving an electrolyte salt in an organic solvent. Examples of the organic solvent include cyclic carbonates such as propylene carbonate and ethylene carbonate, and chain carbonates such as dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate. The electrolyte salt is, for example, LiClO ₄ , LiBF ₄ , and LiPF ₆ .

  The case 3 is formed by joining the opening peripheral edge 34 of the case main body 31 and the peripheral edge of the cover plate 32 in an overlapped state. In the case 3, an internal space 33 is defined by the case main body 31 and the lid plate 32 (see FIG. 2).

  The case main body 31 includes a plate-like closing part 311 and a cylindrical body part 312 connected to the periphery of the closing part 311.

  The closing part 311 is located at the lower end of the case body 31 when the case body 31 is arranged with the opening facing upward (that is, the bottom wall of the case body 31 when the opening faces upward). ) Part. The blocking part 311 has a rectangular shape when viewed from the normal direction of the blocking part 311.

  Hereinafter, the long side direction of the blocking part 311 is defined as the X-axis direction, the short side direction of the blocking part 311 is defined as the Y-axis direction, and the normal direction of the blocking part 311 is defined as the Z-axis direction.

  The body portion 312 has a flat rectangular tube shape. The body portion 312 has a pair of long wall portions 313 extending from the long side at the periphery of the closing portion 311 and a pair of short wall portions 314 extending from the short side at the periphery of the closing portion 311. That is, the pair of long wall portions 313 are opposed to each other with an interval in the Y-axis direction (specifically, an interval corresponding to the short side of the periphery of the closing portion 311), and the pair of short wall portions 314 are spaced in the X-axis direction. (In detail, they are opposed to each other with a gap corresponding to the long side of the periphery of the blocking portion 311).

  As described above, the case body 31 has a rectangular tube shape (that is, a bottomed rectangular tube shape) in which one end portion in the opening direction (Z-axis direction) is closed. The case body 31 accommodates the electrode body 2 in a state in which the winding central axis C direction (see FIG. 4) coincides with the X-axis direction.

  The lid plate 32 is a plate-like member that closes the opening of the case body 31. Specifically, the contour shape of the cover plate 32 corresponds to the opening peripheral edge 34 of the case body 31 when viewed from the Z-axis direction. That is, the lid plate 32 is a rectangular plate-like member that is long in the X-axis direction when viewed from the Z-axis direction.

  The lid plate 32 of the present embodiment is provided with a liquid injection hole 325 for injecting an electrolytic solution (see FIG. 3). The liquid injection hole 325 penetrates the lid plate 32 in the Z-axis direction (thickness direction). The liquid injection hole 325 is sealed (sealed) with a liquid injection stopper 326. That is, the case 3 has a liquid injection stopper 326 that seals the liquid injection hole 325 of the lid plate 32. The liquid filling tap 326 of this embodiment is fixed to the lid plate 32 by welding.

  The external terminal 4 is a part that is electrically connected to an external terminal of another power storage element or an external device. The external terminal 4 is formed of a conductive member. For example, the external terminal 4 is formed of a highly weldable metal material such as an aluminum-based metal material such as aluminum or an aluminum alloy, or a copper-based metal material such as copper or a copper alloy. The external terminal 4 of this embodiment has a surface 41 to which a bus bar or the like can be welded (see FIGS. 1 to 3).

  The current collector 5 has a connection portion 52 that is connected to the electrode body 2 in a state of being superimposed on the outer surface of the electrode body 2. The current collector 5 is formed of a conductive member and is disposed along the inner surface of the case 3. The current collector 5 is directly or indirectly connected to the electrode body 2 so as to be energized. The current collector 5 of the present embodiment is connected to the electrode body 2 through the clip member 50 so as to be energized. That is, the electrical storage element 1 includes a clip member 50 that connects the electrode body 2 and the current collector 5 so as to allow energization.

  Specifically, the current collector 5 includes a main body 51 connected to the external terminal 4 and a connection portion 52 extending from the main body 51. The main body 51 is a plate-like portion extending in the X-axis direction along the cover plate 32, and the connecting portion 52 extends from the end on the short wall portion 314 side of the main body 51 toward the closing portion 311 side along the long wall portion 313. It is a plate-like part that extends. In the current collector 5 of the present embodiment, the connection portion 52 extends from one end edge and the other end edge of the main body 51 in the Y-axis direction. That is, the current collector 5 of the present embodiment has one main body 51 and a pair of connection portions 52. Then, the pair of connection portions 52 sandwich the electrode body 2 (specifically, the connected portion 26) in the Y-axis direction. The connecting portion 52 is joined to the connected portion 26 of the electrode body 2 by caulking joining such as joining by TOX (registered trademark). In the electricity storage device 1 according to the present embodiment, as shown in FIG. 6, the connecting portion 52, the clip member 50, and the connected portion 26 of the electrode body 2 are crimped and joined to each other, and are concavo-convexly fitted. doing.

  This caulking-joined part (specifically, the part from the second concave part 522A of the connection part 52 in FIG. 6 to the convex part 502A of the surface of the opposing piece 502 of the clip member 50 on the hollow part side: 7 ”) is configured to protrude toward the hollow portion 27 of the electrode body 2 (that is, the outer side is concave and the hollow portion side is convex).

  In this crimping joint part 7, for example, a part where the divided connected part 261 sandwiched by the clip member 50 and the connection part 52 of the current collector 5 are pressed in the stacking direction, It is formed by crimping. Specifically, for example, as shown in FIGS. 7 and 8, the caulking is performed by arranging a die (female mold) D on the hollow portion 27 side and a punch (male mold) P outside the electrode body 2. Are arranged and overlapped with each other (in the example of this embodiment, the connecting portion 52 of the current collector 5 and the divided connected portion 261 sandwiched between the clip members 50) are punched by the punch P. Is pushed into the concave portion D1, and the pushed portion is locally bent, and is joined (compressed) by forming an interlock portion (a portion having an enlarged diameter) on the inner member. In the present embodiment, bonding is performed by TOX (registered trademark) which is a kind of caulking bonding (mechanical clinch). Moreover, the crimping | jointing joining site | part 7 of this embodiment is formed in two in each connection part 52 (refer FIG. 5).

  In the caulking joint part 7, the connection part 52 has a first convex part 521A formed on the first surface 521 facing the electrode body 2 (connected part 26), and a front-back relationship with the first convex part 521A. And a second recess 522A (on the second surface (back surface of the first surface 521) 522 opposite to the first surface 521). Then, the first convex portion 521A of the connection portion 52 is concavo-convexly fitted to the electrode body 2 (specifically, the electrode body 2 via the clip member 50), and the second concave portion 522A of the connection portion 52 is concavo-convex to the spacer 8. It is mated.

  As shown in FIGS. 2, 3, and 5, the current collector 5 configured as described above is disposed on each of the positive electrode and the negative electrode of the electricity storage device 1. In the power storage device 1 of the present embodiment, the case 3 is disposed at positions corresponding to the positive electrode connected portion 26 and the negative electrode connected portion 26 of the electrode body 2. The positive electrode current collector 5 and the negative electrode current collector 5 are formed of different materials. Specifically, the positive electrode current collector 5 is formed of, for example, aluminum or an aluminum alloy, and the negative electrode current collector 5 is formed of, for example, copper or a copper alloy.

  The clip member 50 is sandwiched so that the positive electrode 23 or the negative electrode 24 stacked in the connected portion 26 (specifically, the divided connected portion 261) of the electrode body 2 is bundled. Thereby, the clip member 50 reliably conducts the positive electrodes 23 or the negative electrodes 24 stacked in the connected portion 26. Specifically, as shown in FIGS. 6 and 9, the clip member 50 includes a pair of opposed pieces 501 that are opposed to each other with the divided connected portion 261 (stacked positive electrode 23 or negative electrode 24) of the connected portion 26 interposed therebetween. , 502 and a connecting portion 503 for connecting corresponding end portions of the opposing pieces 501 and 502 to each other. The clip member 50 is formed of a conductive member. The clip member 50 of the present embodiment is formed by bending a plate-shaped metal material so that the cross section has a U shape.

  In the caulking joint portion 7, the first convex portion 521 </ b> A is fitted into one opposing piece (opposing piece opposed to the current collector 5) 501 of the clip member 50, and the other opposing piece 502 is fitted into the other opposing piece 502. The one opposing piece 501 is fitted through the divided connected portion 261 (concave fitting).

  The spacer 8 has an insulating property and is restricted in movement by the case 3. The spacer 8 of this embodiment is formed of resin. The spacer 8 is disposed at each position corresponding to each end portion (in the example of the present embodiment, the connected portion 26) in the X-axis direction of the electrode body 2. That is, the electricity storage device 1 of this embodiment includes a pair of spacers 8.

  As shown in FIG. 10, each spacer 8 includes a pair of overlapping portions 81 that overlap the pair of connection portions 52 from the outside in the Y-axis direction (that is, the direction in which the pair of connection portions 52 sandwich the connected portion 26), And a connecting portion 82 that connects corresponding end portions of the overlapping portion 81.

  Each of the pair of overlapping portions 81 is concavo-convexly fitted with the second concave portion 522 </ b> A of the connecting portion 52 that is opposed to the pair of overlapping portions 81. Specifically, each overlapping portion 81 includes an inner surface (XZ plane (including the X-axis direction and the Z-axis direction) of the long wall portion 313 at a position corresponding to the connected portion 26 (for example, a position overlapping in the Y-axis direction). It is a plate-shaped part which spreads along the surface)). The overlapping portion 81 of the present embodiment extends from the short wall portion 314 in the X-axis direction to the boundary between the connected portion 26 and the main body 20 or the vicinity thereof, and from the closing portion 311 to the vicinity of the lid plate 32 in the Z-axis direction. It extends. The overlapping portion 81 is in contact with the long wall portion 313 via the insulating member 6.

  As shown in FIGS. 11 and 12, the opposing surface 810 facing the connecting portion 52 in the overlapping portion 81 is an insulating convex portion protruding toward the inside of the second concave portion 522A at a position corresponding to the second concave portion 522A. 810A included. That is, the opposing surface 810 includes an insulating convex portion 810A that fits into the second concave portion 522A. The insulating convex portion 810A is closely or substantially in close contact with the second concave portion 522A. The overlapping portion 81 of the present embodiment has the number of insulating convex portions 810 </ b> A corresponding to the number of the second concave portions 522 </ b> A in the connecting portion 52 facing each other.

  In the electricity storage device 1 of the present embodiment, the fitting portion 9 is configured by the insulating convex portion 810A and the crimping joint portion 7 into which the insulating convex portion 810A is fitted. And the fitting site | part 9 is located inside the main body 20 seeing from the X-axis direction (direction which goes to the main body 20 from the to-be-connected part 26) (refer FIG. 13).

  The connecting portion 82 includes a plate-like main body 821 extending along the inner surface (YZ plane (a surface including the Y-axis direction and the Z-axis direction)) of the short wall portion 314, and the hollow portion 27 of the electrode body 2 from the main body 821. A protrusion 822 that protrudes toward the main body 20 side of the electrode body 2.

  The main body 821 connects ends of the pair of overlapping portions 81 on the short wall portion 314 side. The main body 821 of the present embodiment extends from one long wall portion 313 to the other long wall portion 313 of the pair of long wall portions 313 opposed in the Y-axis direction, and extends from the closing portion 311 to the lid plate 32 in the Z-axis direction. It extends to the vicinity. The main body 821 is in contact with the short wall portion 314 via the insulating member 6.

  The protruding portion 822 protrudes from the main body 821 through the hollow portion 27 to the front of the insulating convex portion 810A in the X-axis direction, and extends in the Z-axis. The protruding portion 822 sandwiches the divided connected portion 261 sandwiched between the clip member 50 and the overlapping portion 81. That is, the divided connected portion 261 is sandwiched between the protruding portion 822 and the overlapping portion 81 together with the clip member 50 sandwiching the divided connected portion 261, so that the Y axis of the divided connected portion 261 and the clip member 50 is The movement in the direction is restricted, which makes it difficult for the insulating convex portion 810A to come off from the second concave portion 522A.

  The spacer 8 (the pair of overlapping portions 81 and the connecting portion 82) configured as described above is integrally formed of resin. Thus, since the spacer 8 is made of resin, for example, as shown in FIG. 14, the pair of connecting portions 52 is expanded (separated) between the ends of the pair of overlapping portions 81 opposite to the connecting portions 82. Corresponding insulating projections 810A can be fitted into the respective second recesses 522A.

  The insulating member 6 is disposed between the case 3 (specifically, the case main body 31) and the electrode body 2, the current collector 5, and the spacer 8. The insulating member 6 is made of an insulating resin. The insulating member 6 of this embodiment is a bag shape formed by bending an insulating sheet-like member cut into a predetermined shape.

  In the power storage device 1 described above, the spacer 8 whose movement is restricted by the case 3 and the current collector 5 (specifically, the connecting portion 52) connected to the electrode body 2 are connected in the Y-axis direction (connected to the electrode body 2). The insulating convex portion 810A protruding in the overlapping direction with the portion 52 and the second concave portion 522A including the peripheral edge surrounding the insulating convex portion 810A are fitted (concavo-convex fitting). For this reason, relative movement of the spacer 8 and the current collector 5 in the direction perpendicular to the Y-axis direction (direction perpendicular to the overlapping direction) is suppressed. As a result, the electrode body 2 can be prevented from swinging in the direction perpendicular to the Y-axis direction via the connecting portion 52 and the spacer 8, and damage to the electrode body 2 and the current collector 5 due to the swing can be suppressed. It is done.

  In the electricity storage device 1 of the present embodiment, the first convex portion 521A of the connection portion 52 is unevenly fitted to the electrode body 2, and the second concave portion 522A of the connection portion 52 is unevenly fitted to the spacer 8. Thus, since the electrode body 2 and the spacer 8 are respectively concavo-convexly fitted to the connection portion 52 at the same position (front and back positions) in the XZ plane direction of the connection portion 52, the power storage according to the present embodiment. In the element 1, the electrode body 2 and the current collector 5 are formed without separately forming a portion where the connection portion 52 and the electrode body 2 are unevenly fitted and a portion where the connection portion 52 and the spacer 8 are unevenly fitted. The relative movement of the spacer 8 in the direction orthogonal to the Y-axis direction (fitting direction) with respect to can be suppressed.

  Moreover, in the electrical storage element 1 of this embodiment, the fitting part 9 in which the spacer 8, the connection part 52, and the electrode body 2 are unevenly fitted is from the X-axis direction (the direction from the connected part 26 toward the main body 20). It is located inside the main body 20 as seen (see FIG. 13). For this reason, when the case 3 is arranged close to the main body 20 of the electrode body 2 in a direction orthogonal to the X-axis direction (Y-axis direction in the example of the present embodiment), the fitting portion 9 does not interfere. That is, when the fitting part 9 is located outside the main body 20 in the orthogonal direction, the case 3 comes into contact with the spacer 8 including the fitting part 9, so that the case 3 is almost covered with the electrode 2. Although it cannot be arranged in a state of being close to the main body 20, in the power storage device 1 of the present embodiment, the case 3 (long wall portion 313) can be arranged in a state of being close to the main body 20 of the electrode body 2 to the limit. Become.

  Moreover, in the electrical storage element 1 of the present embodiment, the spacer 8 includes a pair of overlapping portions 81 that overlap the pair of connection portions 52 in the Y-axis direction, and each of the pair of overlapping portions 81 corresponds to the opposing connection portion 52. The second concave portion 522A and the concave and convex portion are fitted (see FIG. 10).

  For this reason, the pair of connection portions 52 that sandwich the electrode body 2 are located between the pair of overlapping portions 81 in the sandwiching direction (Y-axis direction), and thereby the current collector 5 (the pair of connections in the Y-axis direction). The movement of the part 52) is restricted. As a result, the movement (swing) of the electrode body 2 in the Y-axis direction is also suppressed. That is, the electrode body 2 has a direction perpendicular to the Y-axis direction of the electrode body 2 (direction along the XZ plane) by fitting between the insulating protrusion 810A and the second recess 522A in the spacer 8 and the current collector 5. ) Is suppressed between the pair of overlapping portions 81 via the pair of connection portions 52, and the swing in the Y-axis direction of the electrode body 2 is also suppressed. Movement in the direction (oscillation) is also suppressed.

  Moreover, in the electrical storage element 1 of this embodiment, the spacer 8 is arrange | positioned in each of the position corresponding to each edge part in the X-axis direction (direction where the winding center axis C is extended) of the electrode body 2. FIG. Therefore, the spacer 8 and the current collector 5 (specifically, the connection portion 52) are fitted by the insulating convex portion 810A and the second concave portion 522A at positions corresponding to the respective end portions in the X-axis direction of the electrode body 2. As a result, the swinging of the electrode body 2 in the direction orthogonal to the Y-axis direction (the direction along the XZ plane) is more reliably suppressed.

  In addition, the electrical storage element of this invention is not limited to the said embodiment, Of course, a various change can be added in the range which does not deviate from the summary of this invention. For example, the configuration of another embodiment can be added to the configuration of a certain embodiment, and a part of the configuration of a certain embodiment can be replaced with the configuration of another embodiment. Furthermore, a part of the configuration of an embodiment can be deleted.

  In the power storage device 1 of the above embodiment, the protruding portion 822 of the spacer 8 protrudes from the main body 821 to the front of the insulating convex portion 810A in the X-axis direction, but is not limited to this configuration. For example, as shown in FIG. 15, the protrusion 822 may protrude to a position beyond the insulating protrusion 810A. The projecting portion 822 has a recess 823 into which the caulking joint portion 7 is fitted at a position facing the caulking joint portion 7 projecting from both sides in the Y-axis direction.

  In this case, the overlapping portion 81 and the protruding portion 822 of the spacer 8 overlap with the end portion of the separator 25 in the X-axis direction up to the position where the separator 25 is disposed in the X-axis direction as shown in FIG. Position, i.e. up to the body 20). In this case, the shape of the front end portion in the X-axis direction of the overlapping portion 81 and the protruding portion 822 is made to be a shape along the surface of the electrode body 2, and the electrode body 2 is formed between the front end portions of the overlapping portion 81 and the protruding portion 822. By sandwiching, the end portion of the separator 25 is suppressed against the electrodes 23 and 24. This makes it difficult for a gap to be formed between the end portion of the separator 25 and the electrodes 23 and 24, and as a result, prevents entry of contaminants such as contamination from the gap between the separator 25 and the electrodes 23 and 24. Can do.

  Further, as long as the protruding portion 822 protrudes to a position beyond the insulating protruding portion 810A and has the recessed portion 823, the spacer 8 may be configured without the overlapping portion 81 (see FIG. 17). In this case, the connection part 52 is disposed so as to contact the divided connection part 261 or the facing piece 502 of the clip member 50 from the hollow part side. Even with such a configuration, the spacer 8 and the connecting portion 52 are protruded in the X-axis direction (the overlapping direction of the electrode body 2 and the connecting portion 52) and the recessed portion 823 including the peripheral edge surrounding the protruding portion 502A. Therefore, the relative movement of the spacer 8 and the current collector 5 in the direction perpendicular to the Y-axis direction is suppressed. As a result, the electrode body 2 can be prevented from swinging in the direction perpendicular to the Y-axis direction via the connecting portion 52 and the spacer 8, and damage to the electrode body 2 and the current collector 5 due to the swing can be suppressed. It is done.

  In the electricity storage device 1 of the above embodiment, the spacer 8 and the connection portion 52 are concavo-convexly fitted by the insulating convex portion 810A of the spacer 8 and the concave portion (second concave portion) 522A of the connection portion 52. It is not limited to the configuration. For example, as shown in FIG. 18, the concave and convex fitting may be performed by an insulating concave portion 810 </ b> B provided in the spacer 8 and a convex portion (second convex portion) 522 </ b> B provided in the connecting portion 52. Further, as shown in FIG. 19, the portion of the connecting portion 52 that fits the convex portion 522B is a through hole 810C corresponding to the convex portion 522B (that is, including the peripheral edge surrounding the convex portion 522B). Also good.

  In the electricity storage device 1 of the above-described embodiment, the current collector 5 has a pair (two) of connection portions 52, but is not limited to this configuration. As shown in FIG. 20, the current collector 5 may have a configuration having one connection portion 52. In this case, in the spacer 8, a convex part that fits into the caulking joint part 7 is provided at a position corresponding to the caulking joint part 7 of one overlapping part 81, and a position corresponding to the caulking joint part 7 of the other overlapping part 81. A concave portion into which the crimping joint portion 7 is fitted is provided, and the connection portion 52 may be sandwiched between the pair of overlapping portions 81.

  Further, the current collector 5 may have a configuration having three or more connection portions 52.

  In the electricity storage device 1 of the above-described embodiment, the crimp joint portion 7 protrudes from the outside of the electrode body 2 toward the hollow portion 27 in the Y-axis direction, but is not limited to this configuration. The caulking joint portion 7 may protrude in a direction from the hollow portion 27 in the Y-axis direction toward the outside of the electrode body 2. In this case, a portion corresponding to the first convex portion 521A in the connecting portion 52 of the embodiment is a concave portion (first concave portion), and a portion corresponding to the second concave portion 522A is a convex portion (second convex portion). Then, by fitting the electrode body 2 (connected portion 26) into the concave portion, the connecting portion 52 and the electrode body 2 (connected portion 26) are concavo-convexly fitted, and the convex portion is fitted into the spacer 8. As a result, the connecting portion 52 and the spacer 8 are unevenly fitted.

  In the electricity storage device 1 of the above embodiment, the position where the electrode body 2 and the current collector 5 are unevenly fitted and the position where the current collector 5 and the spacer 8 are unevenly fitted are the same position in the XZ plane direction. That is, the electrode body 2, the current collector 5, and the spacer 8 are integrally fitted in the concave and convex portions at the fitting portion 9, but the configuration is not limited thereto. The position where the electrode body 2 and the current collector 5 are unevenly fitted and the position where the current collector 5 and the spacer 8 are unevenly fitted may be different positions in the XZ plane direction.

  In the electricity storage device 1 of the above embodiment, the fitting portion 9 is located inside the main body 20 when viewed from the X-axis direction (see FIG. 13), but is not limited to this configuration. For example, a part of the fitting portion 9 may be located outside the main body 20 when viewed from the X-axis direction.

  Moreover, in the electrical storage element 1 of the said embodiment, the clip member 50 is crimped with the to-be-connected part 26 and the electrical power collector 5 of the electrode body 2 (it is TOX (trademark) in the example of the said embodiment). That is, the connected portion 26 is sandwiched (clipped) at a position including the crimping joint portion 7, but is not limited to this configuration. The clip member 50 may have a configuration in which the connected portion 26 is sandwiched (clipped) at a position avoiding the crimping joint portion 7.

  Moreover, in the said embodiment, although the case where an electrical storage element was used as a nonaqueous electrolyte secondary battery (for example, lithium ion secondary battery) which can be charged / discharged was demonstrated, the kind and magnitude | size (capacity | capacitance) of an electrical storage element are arbitrary. It is. Moreover, in the said embodiment, although the lithium ion secondary battery was demonstrated as an example of an electrical storage element, it is not limited to this. For example, the present invention can be applied to various secondary batteries, other primary batteries, and power storage elements of capacitors such as electric double layer capacitors.

  The power storage element (for example, battery) 1 may be used in a power storage device 11 (a battery module when the power storage element is a battery) 11 as shown in FIG. The power storage device 11 includes at least two power storage elements 1 and a bus bar member 12 that electrically connects two (different) power storage elements 1 to each other. In this case, the technique of the present invention only needs to be applied to at least one power storage element 1.

  DESCRIPTION OF SYMBOLS 1 ... Power storage element, 2 ... Electrode body, 20 ... Main body, 21 ... Core, 22 ... Laminated body, 23 ... Positive electrode (electrode), 231 ... Metal foil, 232 ... Positive electrode active material layer, 24 ... Negative electrode (electrode), 241 ... Metal foil, 242 ... Negative electrode active material layer, 25 ... Separator, 26 ... Connected part, 261 ... Divided connected part, 27 ... Hollow part, 3 ... Case, 31 ... Case body, 311 ... Closure part, 312 ... Body part, 313 ... Long wall part, 314 ... Short wall part, 32 ... Cover plate, 325 ... Injection hole, 326 ... Injection stopper, 33 ... Internal space, 34 ... Opening peripheral edge part, 4 ... External terminal, 41 ... Surface 5 ... current collector, 50 ... clip member, 501, 502 ... opposing piece, 502A ... convex portion, 503 ... connecting portion, 51 ... main body, 52 ... connection portion, 521 ... first surface, 521A ... first convex portion 522 ... Second surface, 522A ... Second concave portion, 522B ... Convex portion (second convex portion), 6 ... Insulation 7, caulking joint site, 8 spacer, 81 overlapping portion, 810 A facing surface, 810 A insulating projection, 810 B insulating recess, 810 C through-hole, 82 connecting portion, 821 body, 822 projecting Part, 823 ... concave part, 9 ... fitting part, 11 ... power storage device, 12 ... bus bar member, C ... winding central axis, D ... die, D1 ... concave part, P ... punch

Claims (5)

Case and
An external terminal disposed outside the case;
An electrode body disposed inside the case;
A current collector having a connection portion connected to the electrode body in a state of being superimposed on the outer surface of the electrode body, and connecting the electrode body and the external terminal;
A spacer having an insulating property and disposed between the case and the current collector and restricted in movement by the case, and
Either one of the connection part or the spacer of the current collector has a convex part protruding in the overlapping direction of the connection part of the current collector with respect to the electrode body,
Either the connection part or the spacer of the current collector has a concave part or a hole including a peripheral edge surrounding the convex part. The connecting portion includes a first concave portion facing the electrode body and a second convex portion facing the first concave portion, or a first convex portion facing the electrode body and the first convex portion. A second recess in a front-back relationship with
The first concave portion or the first convex portion of the connecting portion is unevenly fitted with the electrode body, and the second convex portion or the second concave portion of the connecting portion is unevenly fitted with the spacer. 2. The electricity storage device according to 1. The electrode body has a main body in which an active material layer is disposed, and a connected portion that is adjacent to the main body and to which the connecting portion of the current collector is connected,
The fitting portion where the spacer, the connection portion, and the electrode body are unevenly fitted is located inside the main body as viewed from the direction from the connected portion toward the main body. Power storage element. The current collector includes a pair of connection portions that sandwich the electrode body,
The spacer includes a pair of overlapping portions that overlap the pair of connection portions in a direction in which the pair of connection portions are sandwiched,
Each of the pair of connection portions has the second concave portion at a position facing the overlapping portion,
4. The power storage device according to claim 2, wherein each of the pair of overlapping portions is concavo-convexly engaged with the second concave portion of the facing connection portion. The electrode body has a wound electrode,
5. The power storage device according to claim 2, wherein the spacer is disposed at each of positions corresponding to end portions in the winding central axis direction of the electrode body.

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