JP6880483B2 - Power storage element - Google Patents

Description

The present invention relates to a power storage element including a spacer that regulates the movement of the electrode body with respect to the case.

Conventionally, a battery having an insulating cover arranged between an outer can and a positive electrode lead and a negative electrode lead has been known (see Patent Document 1). This battery is attached to the outer can, the winding electrode group housed in the outer can, the positive electrode lead and the negative electrode lead connected to the winding electrode group, and the opening of the outer can, and the positive electrode terminal and the negative electrode terminal are attached. The cover is provided with a positive electrode insulating cover arranged between the positive electrode lead and the outer can, and a negative electrode insulating cover arranged between the negative electrode lead and the outer can.

The winding 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 winding electrode group is housed in the outer can so as to face the direction perpendicular to the winding axis.

The positive electrode leads are a connection plate connected to the positive electrode terminal, and first and first sandwiching portions that are bifurcated from the connection plate and extend to the winding electrode group in a direction perpendicular to the winding axis. It has two sandwiching 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 leads are a connection plate connected to the negative electrode terminal, and first and first sandwiching portions that are bifurcated from the connection plate and extend to the winding electrode group in a direction perpendicular to the winding axis. It has two sandwiching 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 electrode insulating covers are 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 electrode leads, and the sandwiching strips and the current collecting tabs are fitted to each other. cover.

By arranging the insulating cover in this way, the swing of the winding electrode group inside the battery is suppressed. As a result, it is possible to prevent the current collecting tab from being deformed or damaged and being disconnected from the lead.

However, in the battery, the insulating cover is arranged along the strip of the lead and is not constrained in the extending direction of the strip, so that the lead and the winding electrode group may be allowed to move in the direction. Therefore, in the battery, it is not possible to sufficiently prevent damage to the leads and the wound electrode group in a vibrating environment.

Japanese Unexamined Patent Publication No. 2012-227110

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

The power storage element of this embodiment is
With the case
External terminals located on the outside of the case
The electrode body arranged inside the case and
A current collector having a connecting portion connected to the electrode body in a state of being overlapped with the outer surface of the electrode body and connecting the electrode body and the external terminal.
It is provided with a spacer which is insulating and is arranged between the case and the current collector and whose movement is restricted by the case.
Either the connection portion of the current collector or the spacer has a convex portion protruding in the superposition direction of the connection portion of the current collector with respect to the electrode body.
Either or the other of the connection portion or the spacer of the current collector has a recess or a hole including a peripheral edge surrounding the convex portion.

According to this configuration, the spacer whose movement is restricted to the case and the current collector (specifically, the connecting portion) connected to the electrode body surround the convex portion protruding in the superposition direction and the convex portion. Since it is fitted in the recess or the hole including the peripheral edge, the relative movement of the spacer and the current collector in the direction orthogonal to the superposition direction is suppressed. As a result, the electrode body is suppressed from swinging in the direction orthogonal to the superposition direction via the connecting portion and the spacer, and the damage to the electrode body and the current collector due to the swinging is suppressed.

In the power storage element,
The connecting portion is formed on a first concave portion facing the electrode body and a second convex portion having a front-back relationship with the first concave portion, or a first convex portion facing the electrode body and the first convex portion. On the other hand, it has a second recess, which is in a front-to-back relationship.
The first concave portion or the first convex portion of the connecting portion may be concavely fitted with the electrode body, and the second convex portion or the second concave portion of the connecting portion may be concavely fitted with the spacer. ..

According to this configuration, since the electrode body and the spacer are unevenly fitted to the connecting portion at the same position (front and back positions) of the connecting portion, the connecting portion and the electrode body are unevenly fitted to each other. It is possible to suppress the relative movement of the spacer in the direction orthogonal to the fitting direction with respect to the electrode body and the current collector without separately forming the portion where the connecting 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 arranged, and a connected portion adjacent to the main body and to which the connecting portion of the current collector is connected.
The fitting portion where the spacer, the connecting portion, and the electrode body are unevenly fitted may be located inside the main body when viewed from the direction from the connected portion toward the main body.

According to this configuration, the fitting portion (the portion where the spacer, the connecting portion, and the electrode body are unevenly fitted) is located inside the main body when viewed from the direction (predetermined direction) from the connected portion to the main body. Therefore, when the case is arranged close to the main body of the electrode body in the direction orthogonal to the predetermined direction, the fitting portion does not get in the way.

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

According to this 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 connecting portions to the electrode body is restricted, whereby the movement (oscillation) of the electrode body in the overlapping direction is also suppressed. That is, the electrode body is formed in a direction orthogonal to the superposition direction (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 swing is suppressed, the electrode body is located between the pair of overlapping portions via the pair of connecting portions, and the swing of the electrode body in the superposition direction is also suppressed, so that the electrode body moves in any direction ( Swinging) is also suppressed.

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

According to such a configuration, at a position corresponding to each end portion in the winding central axis direction of the electrode body, the spacer and the current collector (specifically, the connecting portion) are a convex portion and a concave portion including a peripheral edge surrounding the convex portion. Alternatively, since the electrode body is fitted with the hole, the swing of the electrode body in the direction orthogonal to the superposition direction can be suppressed more reliably.

From the above, according to the present embodiment, it is possible to provide a power storage element that suppresses the fluctuation of the electrode body and the current collector in the case and suppresses the damage of the electrode body and the current collector.

FIG. 1 is a perspective view of a power storage element according to the present embodiment. FIG. 2 is a cross-sectional view taken along the line II-II of 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 power storage element. FIG. 5 is a perspective view of the power storage element in a state where the case body, the insulating member, and the spacer are removed. FIG. 6 is an enlarged cross-sectional view for explaining the fitting portion. FIG. 7 is a diagram for explaining caulking joints. FIG. 8 is a diagram for explaining caulking joints. FIG. 9 is a perspective view of the pair of clip members. FIG. 10 is a partially enlarged cross-sectional view of the XX position of FIG. FIG. 11 is a perspective view of the spacer. FIG. 12 is a cross-sectional view taken along the line XII-XII of FIG. FIG. 13 is a schematic view for explaining the positional relationship between the main body of the electrode body and the fitting portion as viewed from the X-axis direction. FIG. 14 is a diagram 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 view for explaining a spacer according to another embodiment. FIG. 16 is a schematic view for explaining a spacer according to another embodiment. FIG. 17 is a schematic view for explaining a spacer according to another embodiment. FIG. 18 is a schematic view for explaining a spacer and a fitting portion according to another embodiment. FIG. 19 is a schematic view for explaining a spacer and a fitting portion according to another embodiment. FIG. 20 is a schematic view for explaining a connection portion of a spacer and a current collector according to another embodiment. FIG. 21 is a schematic view of a power storage device including the power storage element of the above embodiment.

Hereinafter, an embodiment of the power storage element according to the present invention will be described with reference to FIGS. 1 to 14. The power storage element includes a primary battery, a secondary battery, a capacitor, and the like. In the present embodiment, a rechargeable secondary battery will be described as an example of the power storage element. The name of each component (each component) of the present embodiment is that of the present embodiment, and may be different from the name of each component (each component) in the background technology.

The power storage element of this embodiment is a non-aqueous electrolyte secondary battery. More specifically, the power storage element is a lithium ion secondary battery that utilizes electron transfer generated by the movement of lithium ions. This type of power storage element supplies electrical energy. The power storage element may be used alone or in a plurality. Specifically, the power storage element is used alone when the required output and the required voltage are small. On the other hand, when at least one of the required output and the required voltage is large, the power storage element is used in the power storage device in combination with another power storage element. In the power storage device, the power storage element used in the power storage device supplies electrical energy.

As shown in FIGS. 1 to 5, the current collecting element includes an electrode body 2, a case 3 in which the electrode body 2 is arranged inside, an external terminal 4 in which at least a part thereof is arranged outside the case 3, and a case. A current collector 5 that connects the electrode body 2 and the external terminal 4 inside the 3 and a spacer 8 that is arranged between the case 3 and the current collector 5 are provided. Further, the power storage element 1 includes an insulating member 6 or the like that covers the electrode body 2 and the current collector 5 inside the case 3. In the power storage element 1 of the present embodiment, the electrode body 2, the current collector 5, and the spacer 8 are unevenly fitted to each other. In addition, in FIG. 3, the electrode body 2 and the current collector 5 show the state before the uneven fitting.

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

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

The winding core 21 is usually formed of an insulating material. The winding core 21 of this embodiment has a flat tubular shape. The winding core 21 is formed by winding a flexible or thermoplastic sheet.

The positive electrode 23 has a strip-shaped metal foil 231 and a positive electrode active material layer 232 superimposed on the metal foil 231. The positive electrode active material layer 232 is superposed on the metal foil 231 in a state where one edge portion (uncovered portion) in the width direction of the metal foil 231 is exposed. The metal foil 231 of the present embodiment is, for example, an aluminum foil.

The negative electrode 24 has a strip-shaped metal foil 241 and a negative electrode active material layer 242 superimposed on the metal foil 241. The negative electrode active material layer 242 is formed in a state where the other edge portion (uncovered portion) of the metal foil 241 in the width direction (opposite side to the uncoated portion of the metal foil 231 of the positive electrode 23) is exposed. It is stacked on 241. The metal leaf 241 of the present 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 of being insulated by the separator 25. That is, in the electrode body 2 of the present 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 arranged between the positive electrode 23 and the negative electrode 24. As a result, in the electrode body 2 (specifically, the laminated body 22), the positive electrode 23 and the negative electrode 24 are insulated from each other. Further, the separator 25 holds the electrolytic solution in the case 3. As a result, when the power storage element 1 is charged and discharged, lithium ions can move between the positive electrode 23 and the negative electrode 24, which are alternately laminated with the separator 25 in between. The separator 25 is made of, for example, a porous membrane such as polyethylene, polypropylene, cellulose, or polyamide.

The width direction dimension of the separator 25 is larger than the width of the negative electrode active material layer 242. The separator 25 is arranged between the positive electrode 23 and the negative electrode 24 in which the positive electrode active material layer 232 and the negative electrode active material layer 242 are overlapped with each other in a state of being displaced in the width direction so as to overlap in the thickness direction (stacking direction). To. 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 uncoated portion of the positive electrode 23 protrudes in the width direction (direction orthogonal to the stacking direction) from the overlapping region of the positive electrode 23 and the negative electrode 24, and the uncoated portion of the negative electrode 24 is the positive electrode 23 and the negative electrode 24. It protrudes from the overlapping region in the width direction (the direction opposite to the protruding direction of the uncoated portion of the positive electrode 23). The electrode body 2 is formed by winding the positive electrode 23, the negative electrode 24, and the separator 25 (that is, the laminated body 22) laminated in such a state.

In the electrode body 2 of the present embodiment, the electrode body 2 is formed by a portion where the positive electrode active material layer 232 of the positive electrode 23 is arranged, a portion where the negative electrode active material layer 242 of the negative electrode 24 is arranged, and a portion where the separator 25 is laminated. The main body 20 in the above is configured. Further, the connected portion 26 in the electrode body 2 is formed by the portion where only the uncoated portion of the positive electrode 23 or the uncoated portion of the negative electrode 24 is laminated.

The connected portion 26 is a portion of the electrode body 2 that is electrically connected to the current collector 5. The connected portion 26 of the present embodiment has two wound portions 27 (see FIGS. 3 and 4) sandwiched between the wound positive electrode 23, the negative electrode 24, and the separator 25 when 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 uncoated portion of the positive electrode 23 is laminated constitutes the connected portion of the positive electrode in the electrode body 2, and the connected portion 26 in which only the uncoated portion of the negative electrode 24 is laminated constitutes the electrode body 2. Consists of the connected portion of the negative electrode in.

The case 3 has a case main body 31 having an opening and a lid 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, the current collector 5, and the like. The case 3 is formed of a metal that is resistant to the electrolytic solution. Case 3 of the present embodiment is formed of, for example, aluminum or an aluminum-based metal material such as an aluminum alloy.

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

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

The case body 31 includes a plate-shaped closing portion 311 and a tubular body portion 312 connected to the peripheral edge of the closing portion 311.

The closing portion 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, becomes the bottom wall of the case body 31 when the opening faces upward). ) The part. The closed portion 311 has a rectangular shape when viewed from the normal direction of the closed portion 311.

In the following, the long side direction of the closed portion 311 is the X-axis direction, the short side direction of the closed portion 311 is the Y-axis direction, and the normal direction of the closed portion 311 is the Z-axis direction.

The body portion 312 has a flat square tubular shape. The body portion 312 has a pair of long wall portions 313 extending from the long side at the peripheral edge of the closed portion 311 and a pair of short wall portions 314 extending from the short side at the peripheral edge of the closed portion 311. That is, the pair of long wall portions 313 face each other with an interval in the Y-axis direction (specifically, the interval corresponding to the short side at the peripheral edge of the closed portion 311), and the pair of short wall portions 314 are spaced in the X-axis direction. (Specifically, they face each other with an interval corresponding to the long side at the peripheral edge of the closed portion 311).

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

The lid plate 32 is a plate-shaped member that closes the opening of the case body 31. Specifically, the contour shape of the lid plate 32 corresponds to the opening peripheral edge portion 34 of the case body 31 when viewed from the Z-axis direction. That is, the lid plate 32 is a rectangular plate-shaped 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) by a liquid injection plug 326. That is, the case 3 has a liquid injection plug 326 that seals the liquid injection hole 325 of the lid plate 32. The liquid injection plug 326 of the present embodiment is fixed to the lid plate 32 by welding.

The external terminal 4 is a portion electrically connected to an external terminal of another power storage element, an external device, or the like. 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 the present 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 connecting portion 52 connected to the electrode body 2 in a state of being superposed on the outer surface of the electrode body 2. The current collector 5 is formed of a conductive member and is arranged along the inner surface of the case 3. Further, 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 electrically connected to the electrode body 2 via the clip member 50. That is, the power storage element 1 includes a clip member 50 that connects the electrode body 2 and the current collector 5 so as to be energized.

Specifically, the current collector 5 has a main body 51 connected to the external terminal 4 and a connecting portion 52 extending from the main body 51. The main body 51 is a plate-shaped portion extending in the X-axis direction along the lid plate 32, and the connecting portion 52 is from the end portion of the main body 51 on the short wall portion 314 side to the closing portion 311 side along the long wall portion 313. It is a plate-shaped part that extends. In the current collector 5 of the present embodiment, the connecting portion 52 extends from each of 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 connecting portions 52. Then, the pair of connecting 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 power storage element 1 of 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 caulked and joined in a laminated state, and are unevenly fitted to each other. doing.

The portion to be caulked (specifically, the portion from the second concave portion 522A of the connecting portion 52 in FIG. 6 to the convex portion 502A of the surface of the opposite piece 502 of the clip member 50 on the hollow portion side: 7 ”) is configured to project 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 the caulking joint portion 7, for example, a portion where the split connected portion 261 sandwiched by the clip member 50 and the connecting portion 52 of the current collector 5 overlap is pressed in the stacking direction, whereby. It is formed by caulking. Specifically, in the caulking joint, for example, as shown in FIGS. 7 and 8, a die (female mold) D is arranged on the hollow portion 27 side, and a punch (male mold) P is placed on the outside of the electrode body 2. Is arranged, and a part of the overlapped portion (in the example of the present embodiment, the connecting portion 52 of the current collector 5 and the divided connected portion 261 in a state of being sandwiched between the clip members 50) is punched by the die D. It is pushed into the concave portion D1 of the above, whereby the pushed portion is locally bent, and an interlock portion (diameter-enlarged portion) is formed on the inner member to join (compress join). In the present embodiment, they are joined by TOX (registered trademark), which is a kind of caulking joint (mechanical clinch). Further, two caulking joint portions 7 of the present embodiment are formed at each connection portion 52 (see FIG. 5).

In the caulking joint portion 7, the connecting portion 52 has a front-back relationship with the first convex portion 521A formed on the first surface 521 facing the electrode body 2 (connected portion 26) and the first convex portion 521A. It has 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 connecting portion 52 is unevenly fitted with the electrode body 2 (specifically, the electrode body 2 via the clip member 50), and the second concave portion 522A of the connecting portion 52 is unevenly fitted with the spacer 8. It is fitted.

As shown in FIGS. 2, 3, and 5, the current collector 5 configured as described above is arranged on the positive electrode and the negative electrode of the power storage element 1, respectively. In the power storage element 1 of the present embodiment, the power storage element 1 is arranged in the case 3 at positions corresponding to the connected portion 26 of the positive electrode of the electrode body 2 and the connected portion 26 of the negative electrode. 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 sandwiches the positive electrode 23 or the negative electrode 24 laminated in the connected portion 26 (specifically, the divided connected portion 261) of the electrode body 2 so as to bundle them. As a result, the clip member 50 ensures that the positive electrodes 23 and the negative electrodes 24 stacked in the connected portion 26 are electrically connected to each other. Specifically, as shown in FIGS. 6 and 9, the clip member 50 is a pair of opposed pieces 501 facing 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 that connects the corresponding ends 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 is U-shaped.

At the caulking joint portion 7, the first convex portion 521A is fitted (concavo-convex fitting) into one facing piece (opposing piece facing the current collector 5) 501 of the clip member 50, and is fitted into the other facing piece 502. Is fitted with one of the opposing pieces 501 via the split connected portion 261 (concavo-convex fitting).

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

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

Each of the pair of overlapping portions 81 is unevenly fitted with the second recess 522A of the opposing connecting portion 52. Specifically, each overlapping portion 81 has 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 that extends 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 its vicinity, and extends from the closing portion 311 to the vicinity of the lid plate 32 in the Z-axis direction. It is extending. 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 facing surface 810 facing the connecting portion 52 in the overlapping portion 81 is an insulating convex portion protruding inward of the second concave portion 522A at a position corresponding to the second concave portion 522A. Includes 810A. That is, the facing surface 810 includes an insulating convex portion 810A that fits into the second concave portion 522A. The insulating convex portion 810A is in close contact with or substantially in close contact with the second concave portion 522A. The overlapping portion 81 of the present embodiment has a number of insulating convex portions 810A corresponding to the number of the second concave portions 522A in the connecting portions 52 facing each other.

In the power storage element 1 of the present embodiment, the fitting portion 9 is formed by the insulating convex portion 810A and the caulking joint portion 7 into which the insulating convex portion 810A is fitted. The fitting portion 9 is located inside the main body 20 when viewed from the X-axis direction (direction from the connected portion 26 toward the main body 20) (see FIG. 13).

The connecting portion 82 includes a plate-shaped main body 821 extending along the inner surface of the short wall portion 314 (YZ plane (plane including the Y-axis direction and the Z-axis direction)), and a hollow portion 27 from the main body 821 to the electrode body 2. It has a protruding portion 822 that projects inside toward the main body 20 side of the electrode body 2.

The main body 821 connects the 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 of the pair of long wall portions 313 facing each other in the Y-axis direction to the other long wall portion 313, 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 split connected portion 261 sandwiched between the clip member 50 and the overlapping portion 81. That is, the split connected portion 261 is sandwiched between the protruding portion 822 and the overlapping portion 81 together with the clip member 50 that sandwiches the split connected portion 261, whereby the Y axis of the split connected portion 261 and the clip member 50 is inserted. 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 (a pair of overlapping portions 81 and a connecting portion 82) configured as described above is integrally molded with resin. As described above, since the spacer 8 is made of resin, for example, as shown in FIG. 14, by widening (separating) the ends of the pair of overlapping portions 81 on the opposite side of the connecting portion 82, the pair of connecting portions 52 The corresponding insulating convex portion 810A can be fitted into each of the second concave portions 522A of the above.

The insulating member 6 is arranged between the case 3 (specifically, the case 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 the present embodiment has a bag shape formed by bending a sheet-shaped member having an insulating property cut into a predetermined shape.

In the above power storage element 1, the spacer 8 whose movement is restricted to the case 3 and the current collector 5 (specifically, the connection portion 52) connected to the electrode body 2 are connected to the electrode body 2 in the Y-axis direction. 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). Therefore, the relative movement of the spacer 8 and the current collector 5 in the direction orthogonal to the Y-axis direction (the direction orthogonal to the superposition direction) is suppressed. As a result, the electrode body 2 is suppressed from swinging in the direction orthogonal to the Y-axis direction via the connecting portion 52 and the spacer 8, and the damage to the electrode body 2 and the current collector 5 due to the swinging is suppressed. Be done.

In the power storage element 1 of the present embodiment, the first convex portion 521A of the connecting portion 52 is unevenly fitted with the electrode body 2, and the second concave portion 522A of the connecting portion 52 is unevenly fitted with the spacer 8. As described above, since the electrode body 2 and the spacer 8 are unevenly fitted to the connecting portion 52 at the same position (front and back positions) of the connecting portion 52 in the XZ plane direction, the storage capacity of the present embodiment is stored. In the element 1, the electrode body 2 and the current collector 5 do not separately form a portion where the connecting portion 52 and the electrode body 2 are unevenly fitted and a portion where the connecting portion 52 and the spacer 8 are unevenly fitted. It is possible to suppress the relative movement of the spacer 8 in the direction orthogonal to the Y-axis direction (fitting direction) with respect to.

Further, in the power storage element 1 of the present embodiment, the fitting portion 9 in which the spacer 8 and the connecting portion 52 and the electrode body 2 are unevenly fitted is from the X-axis direction (direction from the connected portion 26 toward the main body 20). It is located inside the main body 20 as seen (see FIG. 13). Therefore, when the case 3 is arranged close to the main body 20 of the electrode body 2 in the direction orthogonal to the X-axis direction (in the example of the present embodiment, the Y-axis direction), the fitting portion 9 does not interfere. That is, when the fitting portion 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 portion 9, so that the case 3 is brought into contact with the electrode body 2 to the very limit. Although it cannot be arranged close to the main body 20, in the power storage element 1 of the present embodiment, the case 3 (long wall portion 313) can be arranged close to the main body 20 of the electrode body 2. Become.

Further, in the power storage element 1 of the present embodiment, the spacer 8 includes a pair of overlapping portions 81 that overlap the pair of connecting portions 52 in the Y-axis direction, and each of the pair of overlapping portions 81 of the pair of overlapping portions 81 faces each other. It is unevenly fitted with the second recess 522A (see FIG. 10).

Therefore, a pair of connecting portions 52 that sandwich the electrode body 2 are located between the pair of overlapping portions 81 in the sandwiching direction (Y-axis direction), whereby the current collector 5 (a pair of connections) in the Y-axis direction is located. The movement of 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 is in a direction (direction along the XZ plane) orthogonal to the Y-axis direction of the electrode body 2 due to the fitting of the insulating convex portion 810A and the second concave portion 522A in the spacer 8 and the current collector 5. ) Is suppressed, so that the electrode body 2 is located between the pair of overlapping portions 81 via the pair of connecting portions 52, and the swing of the electrode body 2 in the Y-axis direction is also suppressed. Movement (swing) in the direction is also suppressed.

Further, in the power storage element 1 of the present embodiment, the spacer 8 is arranged at a position corresponding to each end portion of the electrode body 2 in the X-axis direction (direction in which the winding center axis C extends). Therefore, at a position corresponding to each end of the electrode body 2 in the X-axis direction, the spacer 8 and the current collector 5 (specifically, the connecting portion 52) are fitted by the insulating convex portion 810A and the second concave portion 522A. As a result, the swing of the electrode body 2 in the direction orthogonal to the Y-axis direction (direction along the XZ plane) is more reliably suppressed.

The power storage element of the present invention is not limited to the above embodiment, and it goes without saying that various modifications can be made without departing from the gist of the present invention. For example, the configuration of one embodiment can be added to the configuration of another embodiment, and a part of the configuration of one embodiment can be replaced with the configuration of another embodiment. In addition, some of the configurations of certain embodiments can be deleted.

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

Further, 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 arranged in the X-axis direction as shown in FIG. It may extend to a position, i.e., to the body 20). In this case, the shape of the tip portion of the overlapping portion 81 and the protruding portion 822 in the X-axis direction is formed along the surface of the electrode body 2, and the electrode body 2 is formed between the tip portions of the overlapping portion 81 and the protruding portion 822. By sandwiching the separator 25, the end portion of the separator 25 is suppressed with respect to the electrodes 23 and 24. This makes it difficult for a gap to be formed between the end of the separator 25 and the electrodes 23 and 24, and as a result, it is possible to prevent foreign matter such as contamination from entering between the separator 25 and the electrodes 23 and 24 from the gap. Can be done.

Further, as long as the protruding portion 822 protrudes to a position beyond the insulating convex portion 810A and has a concave portion 823, the spacer 8 may have a configuration in which the overlapping portion 81 does not exist (see FIG. 17). In this case, the connecting portion 52 is arranged so as to be in contact with the divided connected portion 261 or the opposing piece 502 of the clip member 50 from the hollow portion side. Even with such a configuration, the spacer 8 and the connecting portion 52 have a convex portion 502A protruding in the X-axis direction (the direction in which the electrode body 2 and the connecting portion 52 are overlapped) and a concave portion 823 including a peripheral edge surrounding the convex portion 502A. Since the spacer 8 and the current collector 5 are fitted together (concave and convex fitting), the relative movement of the spacer 8 and the current collector 5 in the direction orthogonal to the Y-axis direction is suppressed. As a result, the electrode body 2 is suppressed from swinging in the direction orthogonal to the Y-axis direction via the connecting portion 52 and the spacer 8, and the damage to the electrode body 2 and the current collector 5 due to the swinging is suppressed. Be done.

Further, in the power storage element 1 of the above embodiment, the spacer 8 and the connecting portion 52 are unevenly fitted with the insulating convex portion 810A of the spacer 8 and the concave portion (second concave portion) 522A of the connecting portion 52. It is not limited to the configuration. For example, as shown in FIG. 18, the insulating concave portion 810B provided in the spacer 8 and the convex portion (second convex portion) 522B provided in the connecting portion 52 may be unevenly fitted. Further, as shown in FIG. 19, the portion of the connecting portion 52 that is unevenly fitted with the convex portion 522B is a through hole 810C corresponding to the convex portion 522B (that is, including a peripheral edge surrounding the convex portion 522B). May be good.

In the power storage element 1 of the above embodiment, the current collector 5 has a pair (two) of connecting portions 52, but the present invention 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 portion that fits into the caulking joint portion 7 is provided at a position corresponding to the caulking joint portion 7 of one overlapping portion 81, and a position corresponding to the caulking joint portion 7 of the other overlapping portion 81. A recess in which the caulking joint portion 7 is fitted may be provided in the seat, and the connecting portion 52 may be sandwiched by the pair of overlapping portions 81.

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

In the power storage element 1 of the above embodiment, the caulking joint portion 7 projects from the outside of the electrode body 2 in the Y-axis direction toward the hollow portion 27, but the configuration is not limited to this. The caulking joint portion 7 may project from the hollow portion 27 in the Y-axis direction toward the outside of the electrode body 2. In this case, the portion of the connecting portion 52 of the above embodiment corresponding to the first convex portion 521A becomes a concave portion (first concave portion), and the portion corresponding to the second concave portion 522A becomes 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 unevenly fitted, and the convex portion is fitted into the spacer 8. By inserting it, the connecting portion 52 and the spacer 8 are unevenly fitted.

In the power storage element 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 positions in the XZ plane direction. That is, the electrode body 2, the current collector 5, and the spacer 8 are integrally unevenly fitted at the fitting portion 9, but the configuration is not limited to this. 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 power storage element 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 the configuration is not limited to this. For example, a part of the fitting portion 9 may be located outside the main body 20 when viewed from the X-axis direction.

Further, in the power storage element 1 of the above embodiment, the clip member 50 is crimped together with the connected portion 26 of the electrode body 2 and the current collector 5 (TOX (registered trademark) is used in the example of the above embodiment). That is, the connected portion 26 is sandwiched (clipped) at a position including the caulking joint portion 7, but the configuration is not limited to this. The clip member 50 may be configured to sandwich (clip) the connected portion 26 at a position avoiding the caulking joint portion 7.

Further, in the above embodiment, the case where the power storage element is used as a chargeable / dischargeable non-aqueous electrolyte secondary battery (for example, a lithium ion secondary battery) has been described, but the type and size (capacity) of the power storage element are arbitrary. Is. Further, in the above embodiment, the lithium ion secondary battery has been described as an example of the power storage element, but the present invention 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, a battery) 1 may be used in a power storage device (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 may be applied to at least one power storage element 1.

1 ... power storage element, 2 ... electrode body, 20 ... main body, 21 ... winding core, 22 ... laminate, 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 ... lid plate, 325 ... liquid injection hole, 326 ... liquid injection plug, 33 ... internal space, 34 ... opening peripheral edge, 4 ... external terminal, 41 ... surface 5, 5 ... Current collector, 50 ... Clip member, 501, 502 ... Opposing piece, 502A ... Convex part, 503 ... Connecting part, 51 ... Main body, 52 ... Connecting part, 521 ... First surface, 521A ... First convex part 522 ... Second surface, 522A ... Second concave part, 522B ... Convex part (second convex part), 6 ... Insulating member, 7 ... Caulking joint part, 8 ... Spacer, 81 ... Overlapping part, 810 ... Opposing surface, 810A ... Insulating convex part, 810B ... Insulating concave part, 810C ... Through hole, 82 ... Connecting part, 821 ... Main body, 822 ... Protruding part, 823 ... Recessed part, 9 ... Fitting part, 11 ... Power storage device, 12 ... Bus bar member, C ... winding center axis, D ... die, D1 ... concave, P ... punch

Claims (5)

With the case
External terminals located on the outside of the case
An electrode body having an electrode arranged inside the case and wound around the case,
It has a pair of connecting portions that are connected to the electrode body in a state of being superposed on the outer surface of the electrode body and sandwich the end portion of the electrode body in the winding axis direction of the electrode , and the electrode body and the outer surface. The current collector that connects the terminals and
It is provided with a spacer which is insulating and is arranged between the case and the current collector and whose movement is restricted by the case.
The spacer includes a pair of overlapping portions that overlap the pair of connecting portions from the outside in the direction in which the pair of connecting portions are sandwiched, and a connecting portion that connects the corresponding ends of the pair of overlapping portions.
Either one of the pair of connecting portions of the current collector or the spacer has a convex portion protruding in the overlapping direction with respect to the electrode body and the connecting portion of the current collector facing the current collector. And
The other of the pair of connecting portions or the spacer of the current collector, have a recess or hole comprising a peripheral surrounding the convex portion,
The convex portions are provided on both sides of the hollow portion of the electrode body.
The connecting portion includes a plate-shaped main body that extends along the end portion of the electrode body in the winding axis direction so as to close the hollow portion, and projects from the plate-shaped main body into the hollow portion of the electrode body. A power storage element comprising a protruding portion that regulates the movement of the end portion of the electrode body in the winding axis direction in the direction in which the convex portion comes out from the concave portion or the hole. Each of the pair of connecting portions is a first concave portion facing the electrode body and a second convex portion having a front-back relationship with the first concave portion, or a first convex portion facing the electrode body and the first convex portion. It has a second concave portion, which is in a front-to-back relationship with one convex portion,
With each of the first recess or the first protrusion of the pair of connecting portions is the electrode body and the recess-projection fitting, each of the second convex portion or the second recess of the pair of connecting portions is the spacer The power storage element according to claim 1, which is unevenly fitted with the power storage element. The electrode body has a main body in which an active material layer is arranged, and a connected portion that is adjacent to the main body and to which each of the pair of connecting portions of the current collector is connected.
The claim that the fitting portion in which each of the spacer, the pair of connecting portions, and the electrode body are unevenly fitted is located inside the main body when viewed from the connected portion toward the main body. 2. The power storage element according to 2. Each of the previous SL pair of connecting portions has the second recess at a position opposite to the overlapping portion,
The power storage element according to claim 2 or 3, wherein each of the pair of overlapping portions is concave-convex-fitted with the second recess of the opposing connection portion. Before SL spacers are disposed in each of positions corresponding to the end portion in the winding direction of the central axis of the electrode body, the power storage device according to any one of claims 2-4.

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