JP2019096466A - Power storage element - Google Patents

Abstract

To provide a power storage element in which deviation between electrodes is prevented.SOLUTION: An electronic element comprises an electrode body 2 having: a first member 21 which includes a first electrode 21, and which is provided at least with one folded part that changes its direction at first-member turning portions 234A and 234B so that one side in a predetermined direction is opened; and a second member 26A which is provided with a folded part 261 that changes its direction at a second-member turning portion 261A so that one side in the predetermined direction is opened, and which includes a second electrode 22 having a polarity different from that of the first electrode 21. The first-member turning portions 234A and 234B come into direct or indirect contact with a valley fold side of the second-member turning portion 261A.SELECTED DRAWING: Figure 4

Description

  The present invention relates to an energy storage device including an electrode body in which a folded back portion of a first member including a first electrode is disposed inside a valley fold surface of a second member including a second electrode.

  Conventionally, a lithium ion secondary battery (hereinafter, simply referred to as "battery") in which one electrode plate of a negative electrode plate and a positive electrode plate is stacked in a zigzag manner is known (see Patent Document 1). Specifically, as shown in FIG. 24, this battery is configured by alternately laminating a negative electrode plate 501, a positive electrode plate 504, and separators 507 inserted between both electrode plates 501 and 504. Electrode stack.

  The negative electrode plate 501 is in close contact with the separator 507 on both sides, and is an electrode plate made of a long flexible material that is alternately folded at predetermined intervals in the longitudinal direction and stacked in a zigzag manner (a long electrode plate Is called). The long electrode plate 501 of the negative electrode has a negative electrode active material layer 503 formed on both sides of the copper foil 502.

  The separator 507 is made of a long insulating film, and is a battery separator capable of moving charges in the thickness direction. The separator 507 is folded in contact with both sides of the long electrode plate 501 of the negative electrode. Specifically, the separator 507 wraps the portion of the copper foil 502 of the long electrode plate 501 on which the negative electrode active material layer 503 is formed from both sides. That is, the long electrode plate 501 and the separator 507 which wraps the both surfaces thereof are integrated to form an integral long object 508.

  The positive electrode plate 504 is in close contact with the separator 507 on both sides, and is a large number of mutually independent strip-shaped electrode plates (referred to as strip-shaped electrode plates). Each strip-shaped electrode plate 504 of the positive electrode has a positive electrode active material layer 506 formed on both sides of the aluminum foil 505.

  A battery 500 is configured by alternately laminating a large number of strip-like electrode plates 504 on both sides of an integral long object 508 including the long electrode plate 501 and the separator 507. That is, when laminating one integral long material 508 and a large number of strip electrode plates 504, the integral long material 508 is folded in a zigzag manner, and the strip electrode plate 504 is inserted from both sides between them to form an integral long The battery 500 has a structure sandwiched by objects 508.

  However, in the above-described battery 500, since the sheet-like (strip-like) strip-like electrode plate 504 is merely sandwiched between the integral long objects 508 folded in a zigzag manner, vibration or the like is applied to the battery 500. As a result, they may be displaced from the arranged position, that is, they may be displaced with respect to the negative electrode plate 501.

JP, 2014-103082, A

  So, this embodiment aims at providing the electrical storage element which a 2nd electrode does not shift | deviate easily with respect to a 1st electrode in an electrode body.

The storage element of the present embodiment is
A first member including at least one folded portion including a first electrode and having a turn that is turned by the first member turn portion such that one side of the predetermined direction is opened, and one side of the predetermined direction is opened And a second member having a turn which is turned at the second member turn portion and including a second electrode different in polarity from the first electrode,
The first member turn abuts directly or indirectly on the valley fold side of the second member turn.

  According to this configuration, the second member turn portion of the second member including the second electrode directly or indirectly abuts the inner side of the second member to the first member turn portion. The movement of the second member is restricted, whereby the displacement of the second electrode relative to the first electrode is suppressed.

In the storage element,
A third member having a turnback portion turned by the third member turn portion so that the other side of the predetermined direction is opened, and including a third electrode of the same polarity as the second electrode,
The first member is opened at the first folded portion which is the folded portion which is turned by the first member turn portion which is the first member turn portion, and the other side of the predetermined direction is opened. As in the case of the serpentine state in which the second folded portion turning in the second first member turn portion is alternately disposed,
The second first member turn may be in direct or indirect contact with the valley fold side of the third member turn.

  According to this configuration, the third member turn portion of the third member including the third electrode directly or indirectly abuts the inner side of the third member turn portion on the second first member turn portion. The movement of the third member to the side is restricted, thereby suppressing the displacement of the third electrode relative to the first electrode.

In addition, the storage element of another embodiment is
An electrode assembly having a plurality of first members and a second member;
Each of the plurality of first members includes at least one turnback portion including a first electrode and being turned at the first member turn portion so that one side in a predetermined direction is opened,
The second member includes a second electrode having a turn which is turned by the second member turn so that one side of the predetermined direction is opened, and including a second electrode different in polarity from the first electrode. ,
The folded portions of the plurality of first members respectively contact the valley fold side of the second member turn portion directly or indirectly.

  In this manner, each of the folded portions of the plurality of first members is in direct or indirect contact with the valley fold side of the second member turn portion, the predetermined portion of each of the plurality of folded portions (each of the plurality of first members) Since the movement to the other side of the direction is restricted, the positional deviation between the plurality of first members is suppressed. That is, the shift of the plurality of first members is suppressed by the second member.

Further, in the storage element,
The second member includes a plurality of second electrodes spaced apart from one another, and a separator superimposed on the plurality of second electrodes.
The interval is disposed at the second member turn portion,
The folded back portion of the first member may directly or indirectly abut the region of the second member turn portion in which the gap is provided.

  According to this configuration, since the gap is disposed in the second member turn portion, the dimension of the second member turn portion in the second member can be suppressed, whereby the size of the electrode body can be suppressed. In addition, since the gap is disposed at the second member turn portion, damage caused by bending of the second electrode can be suppressed.

Further, in the storage element,
The separator comprises a substrate and a particle layer superimposed on the substrate,
The particle layer may have particles and a binder.

  According to this configuration, since the separator has the particle layer having the particles and the binder, when the folded portion of the second member is formed, a fold is easily formed at the position corresponding to the second member turn portion. As a result, positioning of the folded back portion of the second member with respect to the folded back portion of the first member is facilitated by bringing the first member turned portion into direct or indirect contact with the inside of the second member turn portion.

Further, in the storage element,
The first member may have an extension piece extending in the pivot axis direction in a state of being bent from the end edge of the first member turn in the pivot axis direction of the first member turn.

  According to this configuration, since the extension piece extends in a bent state, the strength of the extension piece is secured.

  As described above, according to the present embodiment, it is possible to provide a storage element in which the second electrode is less likely to be displaced with respect to the first electrode in the electrode body.

FIG. 1 is a perspective view of a storage element according to the present embodiment. FIG. 2 is an exploded perspective view of the storage element. FIG. 3 is a cross-sectional view taken along line III-III of FIG. FIG. 4 is a perspective view for explaining an electrode body. FIG. 5 is a schematic cross-sectional view of the V-V position of FIG. 4. FIG. 6 is a diagram for explaining the configuration of the negative electrode. 7 is a cross-sectional view taken along the line VII-VII in FIG. FIG. 8 is a perspective view for explaining the configuration of the serpentine negative electrode. FIG. 9 is a perspective view for explaining the folded portion. FIG. 10 is a diagram for explaining the configuration of the second member. FIG. 11 is a diagram for explaining the configuration of the third member. FIG. 12 is a diagram for explaining the configuration of the second member and the third member arranged at the outermost side. FIG. 13 is a schematic view for explaining a configuration in which a plurality of folding parts are disposed inside the second member folding part. FIG. 14 is a schematic view for explaining a second member having a plurality of second member folding parts. FIG. 15 is a schematic view for explaining the configuration of the second member turn back portion according to the other embodiment. FIG. 16 is a perspective view for explaining the configuration of a negative electrode tab according to another embodiment. FIG. 17 is a schematic view for explaining a second member or a third member connecting adjacent negative electrodes in a zigzag state. FIG. 18 is a schematic view for explaining a second member or a third member connecting adjacent negative electrodes in a zigzag state. FIG. 19 is a diagram for describing a configuration of a second member according to another embodiment. FIG. 20 is a diagram for describing the configuration of an electrode assembly having a plurality of independent first member folding portions. FIG. 21 is a schematic view for explaining the configuration of a member having a folded portion. FIG. 22 is a view for explaining the configuration of a member having a folded portion according to another embodiment. FIG. 23 is a schematic view of a power storage device provided with the power storage element. FIG. 24 is a cross sectional view schematically showing a laminated structure of a conventional battery.

  Hereinafter, an embodiment of a storage element according to the present invention will be described with reference to FIGS. 1 to 12. The storage element includes a primary battery, a secondary battery, a capacitor and the like. In the present embodiment, a chargeable / dischargeable secondary battery will be described as an example of a storage element. In addition, the name of each component (each component) of this embodiment is in this embodiment, and may differ from the name of each component (each component) in background art.

  The storage element of the present embodiment is a non-aqueous electrolyte secondary battery. More specifically, the storage element is a lithium ion secondary battery utilizing electron transfer that occurs as lithium ion moves. This type of storage element supplies electrical energy. The storage element is used singly or in plurality. 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 the required output and the required voltage is large, the storage element is used in the storage device in combination with another storage element. In the storage device, a storage element used for the storage device supplies electrical energy.

  The storage element includes an electrode body 2 as shown in FIGS. 1 to 3. The storage element 1 also includes a case 3 for housing the electrode body 2, an external terminal 4 attached to the case 3 with at least a part exposed to the outside, and a current collector for connecting the electrode body 2 and the external terminal 4. And the body 5 is provided. The storage element 1 also includes an insulating member 6 and the like disposed between the electrode body 2 and the case 3. In each of the drawings, in order to show the structure, the configuration of the electrode body 2 is schematically represented, for example, by exaggerating the thickness of an electrode or the like constituting the electrode body 2.

  The electrode assembly 2 includes a first member including a first electrode 21 and a second member 26A including a second electrode 22 different in polarity from the first electrode 21 as shown in FIGS. 4 and 5. Have. Further, the electrode body 2 has a third member 26 B including a third electrode of the same polarity as the second electrode 22. In the electrode body 2 of the present embodiment, the first electrode 21 is a negative electrode, the second electrode 22 is a positive electrode, and the third electrode is a positive electrode. The first member includes only the negative electrode 21, the second member 26 </ b> A includes the positive electrode 22 and the separator 25, and the third member 26 </ b> B includes the positive electrode and the separator 25. The third electrode of the present embodiment has the same configuration as the second electrode 22, and hence the third electrode is hereinafter referred to as the "positive electrode 22".

  As shown in FIGS. 6 and 7, the negative electrode 21 (in the example of the present embodiment, the first member) includes a metal foil 211 and a negative electrode active material layer 212 superimposed on each side of the metal foil 211. Have. That is, the negative electrode 21 has one metal foil 211 and a pair of negative electrode active material layers 212. The metal foil 211 of the present embodiment is, for example, a copper foil. As shown in FIG. 8, this negative electrode 21 is a long strip, and at least the first member folded portion (folded portion) 23 that is turned (folded back) by the first member turn portion 234 is I have one. The details are as follows.

  The negative electrode active material layer 212 includes a negative electrode active material and a binder.

  The negative electrode active material is, for example, a carbon material such as graphite, non-graphitizable carbon, and graphitizable carbon, or a material that causes an alloying reaction with lithium ions such as silicon (Si) and tin (Sn). The negative electrode active material of the present embodiment is graphite.

  The binder used for the negative electrode active material layer 212 is, for example, polyvinylidene fluoride (PVDF), a copolymer of ethylene and vinyl alcohol, methyl polymethacrylate, polyethylene oxide, polypropylene oxide, polyvinyl alcohol, polyacrylic acid, polymethacryl Acid, styrene butadiene rubber (SBR). The binder of the present embodiment is polyvinylidene fluoride.

  The negative electrode active material layer 212 may further have a conductive aid such as ketjen black (registered trademark), acetylene black, or graphite. The negative electrode active material layer 212 of the present embodiment has no conductive support agent.

  The negative electrode 21 extends in a direction (width direction) away from the main body 210 from a long strip-like main body 210 folded in a zigzag state and long sides (end edges in the width direction (short direction)) 210A of the main body 210. And at least one negative electrode tab (extension piece) 235 (see FIG. 6). In the main body 210 of the present embodiment, a flat portion 233 having a substantially flat plate shape and first member turn portions 234 curved (redirected) around a pivot axis S extending in the width direction of the main body 210 are alternately disposed. By this, it is in a zigzag state (see FIG. 8). In the main body 210, the flat portion 233 and the first member turn portion 234 constitute a first member folded portion 23. The details are as follows.

  As shown in FIG. 9, the first member folding portion 23 is a first surface 231 which is a surface on the valley folding surface side and a surface on the mountain folding surface side (that is, a surface on the opposite side to the first surface 231). It includes a pair of flat portions 233 each having a certain second surface 232 and opposing the first surfaces 231, and a first member turn portion 234 connecting the ends of the pair of flat portions 233. . The negative electrode 21 of the present embodiment includes the first member folded back portion 23 (a first first member folded back portion (first folded back portion) 23A and the The two first member folded portions (second folded portions) 23B) are in a serpentine state (bellows shape) which is continuous in a state in which parts (flat portions 233) thereof are shared.

  In other words, the negative electrode 21 has a first member folded portion (first first member folded portion) 23A folded so that one side in a predetermined direction (left and right direction in FIG. 8) is opened, and The first member folding portion (second first member folding portion) 23B folded back so as to open the other side is alternately disposed in a zigzag state. And when focusing on one first member folded portion (first first member folded portion) 23A, the first member folded portion 23A and the first member adjacent thereto (rear side in FIG. 8) In the folded portion (second first member folded portion) 23B, a first first member turn portion 234A, which is a turn portion of the first first member folded portion 23A, and a second first member folded portion 23B Flat portions 233A, 233B between the second first member turn portion 234B, which is the turn portion of the second embodiment, are shared.

  In this case, as shown in FIG. 8, in the flat portion 233A when focusing on the first first member folding portion 23A, the surface on the valley folding surface side in the first first member folding portion 23A is the first surface It is 231A, and the field (field by the side of a mountain fold side) of the opposite side is the 2nd field 232A. On the other hand, in the flat portion 233B (flat portion 233B shared with the flat portion 233A of the first first member folded portion 23A) focusing on the second first member folded portion 23B, the second first member folded back The surface on the valley folding surface side in the portion 23B is the first surface 231B, and the surface on the opposite side (the surface on the mountain folding surface side) is the second surface 232B. That is, in the flat portions 233A and 233B shared by the first first member folded portion 23A and the second first member folded portion 23B, when focusing on the first first member folded portion 23A, When focusing on the two first member folding parts 23B, the first surface (the surface facing the first member folding part 23) 231 and the second surface (the surface facing the opposite direction in the folding parts) 232 are reversed. become.

  Specifically, as shown in FIG. 8, in the negative electrode 21, flat portions 233 and first member turn portions 234 are alternately formed by alternately turning back the strip-shaped main body 210 at predetermined intervals in the longitudinal direction. It is done. That is, the long strip-shaped main body 210 alternately repeats the mountain fold and the valley fold at the position of the mountain fold line 21A and the position of the valley fold line 21B alternately set at predetermined intervals in the longitudinal direction shown in FIG. It becomes a zigzag state by being released. Thereby, the negative electrode 21 (main body 210) has a plurality of flat portions 233 and a plurality of first member turn portions 234, and each of the plurality of flat portions 233 is arranged in parallel or substantially in parallel. Each of the member turn portions 234 (the first first member turn portion 234A and the second first member turn portion 234B) is the end portions on the one end side of the adjacent flat portion 233 in the longitudinal direction and the other end side The end portions of are alternately connected.

  Hereinafter, the direction in which the flat portions 233 are arranged is taken as the X-axis direction in the orthogonal coordinate system, and the direction in which the first member turn portion 234 is arranged with respect to the flat portion 233 (horizontal direction in FIG. 8) is Y in the orthogonal coordinate system. In the axial direction, the direction in which the pivot axis S of the first member turn portion 234 extends (see FIG. 8) is taken as the Z-axis direction of the orthogonal coordinate system.

  Each of the plurality of flat portions 233 is rectangular as shown in FIG. 6, FIG. 8 and FIG. The flat portion 233 of the present embodiment has a rectangular shape elongated in the Y-axis direction. The entire area of both surfaces of the flat portion 233 is covered with the negative electrode active material layer 212.

  The negative electrode tab 235 protrudes from one side constituting the rectangular contour of the flat portion 233 (in the example of the present embodiment, it extends in the Z axis direction from the edge in the Z axis direction). The negative electrode tab 235 exposes the metal foil 211. That is, the negative electrode tab 235 is constituted only by the metal foil 211 and does not have the negative electrode active material layer 212.

  In the folded negative electrode 21, the negative electrode tabs 235 extending from the flat portions 233 overlap when viewed from the X-axis direction. In the negative electrode 21 of the present embodiment, each negative electrode tab 235 is from the end in one Y-axis direction (right side in FIG. 8) at the end edge in one Z-axis direction of the flat portion 233 (upper side in FIG. 8) It extends in the direction. The negative electrode tabs 235 extending from each of the plurality of flat portions 233 are bundled and connected to the external terminal 4 through the current collector 5 (see FIG. 3). The bundle of negative electrode tabs 235 of the present embodiment is connected to the current collector 5 by welding.

  In each of the plurality of first member turn portions 234, the strip-like main body 210 is pivoted (turned) with the axis extending in the Z-axis direction as the pivot axis S (see FIG. 8) in the negative electrode 21 in a zigzag state. Then, it is a part curved around the pivot axis S). Also in the first member turn portion 234, both surfaces of the metal foil 211 are covered with the negative electrode active material layer 212. That is, in the first member turn portion 234, the negative electrode active material layer 212 is superimposed on the surface of the metal foil 211 facing the inner side (the second member 26A side) of the first member turn portion 234. In addition, in the first member turn portion 234, the negative electrode active material layer 212 is also superimposed on the surface of the metal foil 211 facing the outside of the first member turn portion 234.

  As shown in FIGS. 4 and 5, the second member 26A is a second member folded portion (turned by the second member turn portion 261A) such that one side in the Y-axis direction (predetermined direction) is opened. A folded portion) 261 is provided. As shown in FIG. 10, the second member 26A has a plurality of (two in the example shown in FIG. 10) positive electrodes 22 and a separator 25 overlapping the plurality of positive electrodes 22.

  Each of the two positive electrodes 22 has a metal foil 221 and a positive electrode active material layer 222 superimposed on each of both sides of the metal foil 221 (see FIG. 5). That is, the positive electrode 22 has one metal foil 221 and a pair of positive electrode active material layers 222. The metal foil 221 of the present embodiment is, for example, an aluminum foil.

  The positive electrode active material layer 222 includes a positive electrode active material and a binder.

The positive electrode active material of the present embodiment is, for example, a lithium metal oxide. Specifically, the positive electrode active material is, for example, a composite oxide represented by LiaMebOc (Me represents one or more transition metals) (LiaCoyO ₂ , LiaNixO ₂ , LiaMnzO ₄ , LiaNixCoyMnzO ₂ etc.), LiaMeb XOc) d (Me represents one or more transition metals, and X represents, for example, P, Si, B, V). Polyanion compound (LiaFebPO ₄ , LiaMnbPO ₄ , LiaMnbSiO ₄ , LiaCobPO ₄ F, etc.) ). The positive electrode active material of the present embodiment is LiNi _1/3 Co _1/3 Mn _1/3 O ₂ .

  The binder used for the positive electrode active material layer 222 is the same as the binder used for the negative electrode active material layer 212. The binder of the present embodiment is polyvinylidene fluoride.

  The positive electrode active material layer 222 may further have a conductive aid such as ketjen black (registered trademark), acetylene black, or graphite. The positive electrode active material layer 222 of the present embodiment has acetylene black as a conductive additive.

  Specifically, each of the two positive electrodes 22 has a positive electrode main body (electrode main body) 223 and a positive electrode tab (extension piece) 224 extending from the peripheral edge of the positive electrode main body 223. Specifically, each of the plurality of positive electrodes 22 protrudes from one side of the rectangular positive electrode main body (electrode main body) 223 and one side constituting the rectangular outline of the positive electrode main body 223 (in the example of the present embodiment, in the Z-axis direction) And a positive electrode tab 224 extending in the Z-axis direction from the edge. The positive electrode body 223 of the present embodiment has a rectangular shape elongated in the Y-axis direction. In the positive electrode main body 223, the entire surface of the metal foil 221 is covered with the positive electrode active material layer 222, and the positive electrode tab 224 exposes the metal foil 221. That is, the positive electrode tab 224 is constituted only by the metal foil 221 and does not have the positive electrode active material layer 222.

  The positive electrode active material layer 222 in the positive electrode main body 223 is smaller in the Z-axis direction than the negative electrode active material layer 212 in the flat portion 233 facing in the X-axis direction (specifically, facing via the separator 25).

  The positive electrode tab 224 extends in the Z-axis direction from an end portion in the Y-axis direction at one end (upper side in FIG. 4) of the positive electrode body 223 in the Z-axis direction.

  The two positive electrodes 22 configured as described above are on the side where the positive electrode tab 224 extends in the same direction and the positive electrode tab 224 is disposed in the second member 26A in a state before being folded back as shown in FIG. With the end directed to the opposite side (central side), it is disposed at an interval α. That is, in the second member 26A, the two positive electrodes 22 are arranged such that the positive electrode tabs 224 are located inside (center side: center side in the left and right direction in the example shown in FIG. 10).

  The separator 25 is a member having an insulating property, and is disposed between the negative electrode 21 and the positive electrode 22. Thereby, in the electrode body 2, the negative electrode 21 and the positive electrode 22 are mutually insulated. Further, the separator 25 holds the electrolytic solution in the case 3. Thereby, at the time of charge and discharge of the storage element 1, lithium ions can move between the negative electrode 21 and the positive electrode 22 facing each other across the separator 25.

The separator 25 is in the form of a sheet, and is made of, for example, a porous film of polyethylene, polypropylene, cellulose, polyamide or the like. The separator 25 of the present embodiment is a porous film formed of an inorganic layer (particle layer) containing inorganic particles such as SiO ₂ particles, Al ₂ O ₃ particles, boehmite (alumina hydrate), and a binder. It is formed by providing on the base material. The base material of the separator 25 of the present embodiment is formed of, for example, polyethylene.

  The separator 25 of the present embodiment overlaps the two positive electrodes 22. Specifically, the pair of separators 25 covers the entire positive electrode main body 223 of each of the two positive electrodes 22 so as to sandwich it from both sides. At this time, each of the pair of separators 25 sandwiches the positive electrode 22 with the inorganic layer facing inward (toward the positive electrode 22). In the second member 26A of the present embodiment, the pair of rectangular separators 25 are joined (bonded, welded, etc.) around the respective positive electrodes 22 with the two positive electrodes 22 interposed therebetween. At this time, the positive electrode tab 224 of each positive electrode 22 protrudes from the pair of separators 25, and the bonding is performed avoiding each positive electrode tab 224.

  The second member 26A configured as described above is, as shown in FIGS. 4 and 5, in a state where it is folded back (folded) at the central portion (the position between the two positive electrodes 22), It piles up from the mountain fold surface side to the first member folding part 23A. At this time, the positive electrode tabs 224 of the respective positive electrodes 22 overlap when viewed from the X-axis direction. In the second member 26A in the folded state, the portion folded back is the above-described second member folded portion 261, and the portion where the second member folded portion 261 is turned (curved) is the above-described second It is a member turn part 261A.

  The second member folded portion 261 has the same configuration as the first member folded portion 23. That is, the second member turn back portion 261 connects the pair of flat portions (portion corresponding to the flat portion 233 of the first member turn back portion 23) parallel or substantially parallel to the end portions of the pair of flat portions. And a member turn portion 261A (a portion corresponding to the first member turn portion 234). Then, the second member 26A brings the inner side of the second member turn portion 261A into contact with the first first member turn portion 234A, and the open side of the second member folded portion 261 is the first first member The first first member folded portion 23A is overlapped with the folded portion 23A. That is, the first first member folded portion 23A of the negative electrode 21 is located inside the second member folded portion 261 in a state where the first first member turned portion 234A is in contact with the inside of the second member turned portion 261A. It is arranged. Further, in the second member 26A, the positive electrode 22 is not disposed at the bent portion (second member turn portion 261A / the portion provided with the interval α of FIG. 10). That is, in the second member 26A, each of the two positive electrodes 22 is disposed at a position not overlapping the portion corresponding to the second member turn portion 261A in the separator 25.

  The electrode body 2 of the present embodiment has a plurality of second members 26A. Each of the plurality of second members 26A is disposed at a position where the second members 26A do not overlap with each other between the adjacent first first member folded portions 23A. In the electrode body 2 of the present embodiment, as shown in FIG. 5, each of the plurality of second members 26A is alternately stacked one on another with respect to the plurality of first first member folding portions 23A aligned in the X-axis direction. It is (arranged). In addition, one first first member folded portion 23A is disposed inside the second member folded portion 261 of each second member 26A.

  Of the plurality of second members 26A, the second member 26A located on the outermost side in the X-axis direction of the electrode assembly 2 as shown in FIG. 12 is on the outer side (the lowermost side in FIG. 12) in the X-axis direction. The positive electrode active material layer 222 is not disposed on the surface (the surface opposite to the surface facing the negative electrode 21) of the positive electrode 22 </ b> A facing the outer side of the metal foil 221. That is, the positive electrode active material layer 222 is disposed only in a region facing the negative electrode active material layer 212 (the negative electrode 21) on each surface of the metal foil 221. This is because the positive electrode active material layer 222 does not contribute to the charge and discharge of the storage element 1 even when the positive electrode active material layer 222 is disposed on the surface facing outward.

  As shown in FIGS. 4, 5 and 11, the third member 26B has a plurality of (two in the example shown in FIG. 11) positive electrodes 22 and a separator 25 overlapping the plurality of positive electrodes 22.

  The configuration of each of the two positive electrodes 22 and the separator 25 is the same as that of the second member 26A. In the third member 26B, the arrangement of the two positive electrodes 22 is different from that of the second member 26A. Specifically, in the third member 26B in a state before being folded back as shown in FIG. 11, the positive electrode 22 has an end opposite to the side on which the positive electrode tab 224 extends in the same direction and the positive electrode tab 224 is disposed. With the part directed to the other side (central side), it is arranged at an interval α. That is, in the third member 26B, the two positive electrodes 22 are arranged such that the positive electrode tabs 224 are located outside each other (outside in the left-right direction in the example shown in FIG. 11). Also in the third member 26B, as in the second member 26A, each of the pair of separators 25 sandwiches the positive electrode 22 with the inorganic layer facing inward (toward the positive electrode 22).

  The third member 26B configured as described above, as shown in FIGS. 4 and 5, in a state where it is folded back (folded) at the central portion (the position between the two positive electrodes 22), It piles up on the mountain fold side of the first member turnback portion 23B. At this time, the positive electrode tabs 224 of the respective positive electrodes 22 overlap when viewed from the X-axis direction. The positive electrode tab 224 of the third member 26B also overlaps the positive electrode tab 224 of the second member 26A as viewed in the X-axis direction. In the third member 26B in the folded state, the portion folded back is the third member folded portion (folded portion) 262, and the portion where the third member folded portion 262 is turned (curved) (FIG. 4) In the example shown in FIG. 5 and FIG. 5, the bent portion) is the third member turn portion 262B. The third member folded portion 262 has the same configuration as the first member folded portion 23. That is, the third member folding back portion 262 connects a pair of parallel or substantially parallel flat portions (a portion corresponding to the flat portion 233 of the first member folding back portion 23) and the end portions of the pair of flat portions And a three-member turn portion 262B (a portion corresponding to the first member turn portion 234). Then, the third member 26B brings the third member turn portion 262B into contact with the second first member turn portion 234B, and the open side of the third member turn back portion 262 is the second first member turn back portion It is overlapped with the second first member folding portion 23B in a state of being directed to 23B. That is, the second first member turnback portion 23B of the negative electrode 21 is inside the third member turnback portion 262 in a state where the second first member turn portion 234B is in contact with the inside of the third member turn portion 262B. It is arranged. Further, in the third member 26B, the positive electrode 22 is not disposed at the bent portion (the third member turn portion 262B). That is, in the third member 26B, each of the two positive electrodes 22 is disposed at a position not overlapping the portion of the separator 25 corresponding to the third member turn portion 262B.

  The electrode body 2 of the present embodiment has a plurality of third members 26B. Each of the plurality of third members 26B is disposed at a position where the third members 26B do not overlap with each other between the adjacent second first member folding portions 23B. In the electrode body 2 of the present embodiment, each of the plurality of third members 26B is alternately stacked (arranged with respect to the plurality of second first member folded portions 23B aligned in the X-axis direction) Yes). In addition, one second first member folded portion 23B is disposed inside the third member folded portion 262 of each third member 26B.

  Among the plurality of third members 26B, in the third member 26B positioned on the outermost side in the X-axis direction of the electrode assembly 2 as shown in FIG. 12, X is the same as the second member 26A positioned on the outermost side. The positive electrode active material layer 222 is not disposed on the surface of the positive electrode 22B located outward in the axial direction (uppermost in FIG. 12) facing the metal foil 221. That is, also in the third member 26B, the positive electrode active material layer 222 is disposed only in a region facing the negative electrode active material layer 212 (the negative electrode 21) on each surface of the metal foil 221 as in the second member 26A. . This is because the positive electrode active material layer 222 does not contribute to the charge and discharge of the storage element 1 even when the positive electrode active material layer 222 is disposed on the surface facing outward, as in the second member 26A.

  In the electrode body 2 of the present embodiment, as described above, each of the positive electrode tab 224 of each positive electrode 22 of the second member 26A and the positive electrode tab 224 of each positive electrode 22 of the third member 26B is viewed from the X-axis direction. overlapping. The plurality of positive electrode tabs 224 are bundled and connected via the external terminal 4 and the current collector 5. That is, in the electrode body 2 of the present embodiment, all the positive electrode tabs 224 are bundled at one place. The bundle of positive electrode tabs 224 is connected to the current collector 5 by welding in the same manner as the bundle of negative electrode tabs 235.

  Referring back to FIGS. 1 to 3, 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. In the case 3, an inner space is defined by the case body 31 and the cover plate 32. The case 3 accommodates the electrolytic solution together with the electrode assembly 2 in the internal space.

This electrolyte is a non-aqueous electrolyte. This 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, linear carbonates such as dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate. The electrolyte salt is LiClO ₄ , LiBF ₄ , LiPF ₆ or the like. The electrolyte solution of the present embodiment is prepared by mixing ethylene carbonate, dimethyl carbonate and ethyl methyl carbonate in a mixed solvent prepared by adjusting the ratio of ethylene carbonate: dimethyl carbonate: ethyl methyl carbonate = 3: 2: 5 to 1 mol / L of LiPF ₆ Was dissolved.

  Case 3 is formed of a metal resistant to the above-described electrolyte solution. The case 3 of the present embodiment is formed of, for example, an aluminum-based metal material such as aluminum or an aluminum alloy.

  The case main body 31 includes a plate-like closing portion 311 and a cylindrical trunk portion (peripheral wall) 312 connected to the peripheral edge of the closing portion 311.

  The closing portion 311 is positioned at the lower end of the case body 31 when the case body 31 is disposed in the posture in which the opening is directed upward (that is, the bottom wall portion of the case body 31 when the opening faces upward) ) Site. The closed portion 311 of the present embodiment is rectangular.

  The body portion 312 has a square tube shape, more specifically, a flat square tube shape. The body portion 312 has a pair of long wall portions 313 extending from the long side in the peripheral edge of the closing portion 311 and a pair of short wall portions 314 extending from the short side in the peripheral edge of the closing portion 311. By connecting the short wall portions 314 to the corresponding end portions of the pair of long wall portions 313 (specifically, facing in the X-axis direction), the rectangular cylindrical body portion 312 is formed.

  As described above, the case main body 31 has a rectangular tube shape (that is, a bottomed rectangular tube shape) in which one end in the opening direction (Z-axis direction) is closed.

  The lid plate 32 is a member that closes the opening of the case main body 31. The outline shape of the lid plate 32 is a shape corresponding to the opening peripheral edge portion 310 (see FIG. 2) of the case main body 31. That is, the cover plate 32 is a rectangular plate material long in the Y-axis direction.

  In the case 3 configured as described above, each flat portion 233 of the negative electrode 21 is parallel (substantially parallel) to the long wall portion 313 (that is, each first member turn portion 234 faces the short wall portion 314) Thus, the electrode body 2 in a state of being covered by the insulating member 6 is accommodated (see FIGS. 2 and 3). At this time, the case 3 accommodates the electrode assembly 2 in a state where the entire electrode assembly 2 is compressed (pressed) in the X-axis direction.

  The external terminal 4 is a portion electrically connected to an external terminal of another storage element or an external device. Thus, the external terminal 4 is formed of a conductive member. Further, the external terminal 4 is formed of a metal material having high weldability. For example, the external terminal 4 of the positive electrode is formed of an aluminum-based metal material such as aluminum or an aluminum alloy, and the external terminal 4 of the negative electrode is formed of a copper-based metal material such as copper or a copper alloy. The external terminal 4 of the present embodiment is attached to the cover plate 32 in a state where at least a part is exposed to the outside of the case 3.

  The insulating member 6 is formed of an insulating resin. Specifically, as shown in FIG. 2 and FIG. 3, the insulating member 6 is formed in a bag shape by bending a sheet-like member having insulation which is cut into a predetermined shape. The insulating member 6 of the present embodiment is shaped like a bag along the case 3.

  According to the storage element 1 described above, the second member turn portion 261A of the second member 26A including the positive electrode 22 is disposed on the inner side of the second member turn back portion 261 (first first member turn back portion 23A Abut on the first turn member 234A. For this reason, the movement of the second member 26A to the first first member folding portion 23A side is restricted, whereby the displacement of the positive electrode 22 with respect to the negative electrode 21 is suppressed. In addition, the third member turn portion 262B of the third member 26B including the positive electrode 22 is disposed on the inside of the third member turn back portion 262, and the second first of the negative electrode 21 (second first member turn back portion 23B) It is in contact with the member turn portion 234B. For this reason, the movement of the third member 26B toward the second first member folding portion 23B is restricted, whereby the displacement of the positive electrode 22 with respect to the negative electrode 21 is suppressed.

  That is, movement of the plurality of second members 26A with respect to the negative electrode 21 having the plurality of first first member folding portions 23A (movement to the first first member folding portion 23A side in the second member 26A) Thus, the displacement of the positive electrode 22 with respect to the negative electrode 21 in each first first member folded portion 23A in which the second member 26A is disposed is suppressed. Further, movement of the plurality of third members 26B relative to the negative electrode 21 having the plurality of second first member folding portions 23B (movement to the second first member folding portion 23B side in the third member 26B) Thus, the displacement of the positive electrode 22 with respect to the negative electrode 21 in each second first member folded portion 23B in which the third member 26B is disposed is suppressed.

  In the storage element 1 of the present embodiment, in the second member 26A, the positive electrode 22 is disposed at a position excluding the second member turn portion 261A. Further, also in the third member 26B, the positive electrode 22 is disposed at the position excluding the third member turn portion 262B. As described above, in the storage element 1, the positive electrode 22 is not disposed at the position where it abuts on the second member turn portion 261A of the second member 26A, so the thickness dimension of the second member turn portion 261A of the second member 26A is It is suppressed. In addition, since the positive electrode 22 is not disposed at a position where it abuts on the third member turn portion 262B in the third member 26B, the thickness dimension of the third member turn portion 262B in the third member 26B is also suppressed. By these, the size of the electrode body 2 is suppressed. Moreover, damage to the positive electrode 22 caused by bending of the positive electrode 22 (for example, because the positive electrode 22 is not disposed in the second member turn portion 261A or the third member turn portion 262B of the second member 26A and the third member 26B). Peeling or the like of the positive electrode active material layer 222 can also be suppressed.

  Further, in the storage element 1 of the present embodiment, in the second member 26A, a plurality of (two in the example of the present embodiment) positive electrodes 22 are arranged at an interval α, and the separators 25 overlap the plurality of positive electrodes 22. And the positive electrode 22 is not disposed in the second member turn portion 261A. Thereby, the size of the electrode body 2 can be suppressed, and the productivity of the storage element 1 is improved by handling the plurality of positive electrodes 22 as one member. In addition, in order to obtain this effect (suppression of the size of the electrode body 2 or improvement of productivity), the first first member turn portion 234A of the above embodiment necessarily turns the second member. It is not necessary to provide the structure which contact | abuts to the part 261A. That is, in order to obtain the above-mentioned effect, in the second member 26A, a plurality of positive electrodes 22 are provided regardless of the presence or absence of the configuration in which the first first member turn portion 234A of the above embodiment abuts on the second member turn portion , And the separators 25 may be stacked on the plurality of positive electrodes 22 and the positive electrodes 22 may not be arranged in the second member turn portion 261A.

  Further, in the storage element 1 of the present embodiment, the first negative electrode 21 is adjacent between the first first member turnbacks 23A adjacent in the X axis direction, or between the second first member turnbacks 23B adjacent in the X axis direction. The second member 26A and the third member 26B are disposed such that the two members 26A or the third members 26B do not overlap. According to this configuration, the second members 26A or the third member are disposed between the first first member folded portions 23A adjacent in the X axis direction or between the second first member folded portions 23B adjacent in the X axis direction. The dimensions of the electrode assembly 2 can be reduced as compared with the case where the electrodes 26B overlap with each other.

  Further, in the storage element 1 of the present embodiment, in the positive electrode 22 of the second member 26A and the third member 26B, the positive electrode active material layer 222 faces the negative electrode 21 (negative electrode active material layer 212) on each surface of the metal foil 221 Are arranged only in the Thus, the second member 26A and the third member 26B without the positive electrode active material layer 222 in a region not facing the negative electrode 21 (that is, a member without the positive electrode active material layer 222 not contributing to charge and discharge) are Compared with the case where the second member 26A or the third member 26B having the positive electrode active material layer 222 in a region not facing the negative electrode 21 is used, the electrode assembly 2 can be miniaturized.

  Further, in the second member 26A and the third member 26B of the present embodiment, the positive electrode 22 is covered by the separator 25 having the inorganic layer. Thus, by using the separator 25 having the inorganic layer for the second member 26A and the third member 26B, the second member 26A and the third member 26B are bent at the central portion (the position between the two positive electrodes 22). The folds are tight when you Thereby, the second member 26A and the third member 26B are superimposed on the first member folded portion 23 of the negative electrode 21 (in detail, the first member turn portions 234A and 234B of the first member folded portion 23 are the second member folded portion) When the second member 26A and the third member 26B are overlapped on the first member folding portion 23 so as to abut on the second member turning portion 261A of the H.261 and the third member turning portion 262B of the third member folding portion 262 Positioning of the second member 26A and the third member 26B with respect to the first member folding portion 23 can be facilitated.

  In the conventional storage element, each of the strip-like electrodes (positive electrode in the example of this embodiment) 22 covered (wrapped) in the separator is a long electrode (in the example of this embodiment, the negative electrode) 21 in a zigzag state. In the case of being disposed inside the one-part folded portion 23, normally, the separator covering the positive electrode 22 is not bent. This is because, when a member including a separator having an inorganic layer is disposed in a state where the separator is bent, a new problem occurs in that the inorganic layer of the separator peels off at the bent portion of the separator.

  With respect to this problem, in the storage element 1 of the present embodiment, in the second member 26A and the third member 26B, each of the pair of separators 25 faces the inorganic layer inward (positive electrode 22 side), and the positive electrode 22 is I am caught. Thereby, even if the inorganic layer at the bent portion of the separator 25 is peeled off by bending (turning back) of the second member 26A and the third member 26B, the peeled inorganic layer can be used as the second member 26A and the third member 26B (a pair of Between the separators 25). That is, the inorganic layer peeled off from the separator 25 by the bending of the separator 25 can be prevented from diffusing in the case 3.

  The 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 scope of the present invention. For example, the configuration of one embodiment can be added to the configuration of another embodiment, and part of the configuration of one embodiment can be replaced with the configuration of another embodiment. In addition, some of the configuration of an embodiment can be deleted.

  In the storage element 1 of the above embodiment, one first member folding portion 23 (a first first member folding portion 23A, a second one) is provided inside the one second member folding portion 261 and the one third member folding portion 262. The first member folding portion 23B) is disposed, but the present invention is not limited to this configuration. For example, a plurality of first member folding portions 23 may be disposed inside one second member folding portion 261 or one third member folding portion 262. In this case, as shown in FIG. 13, between a plurality of first member folding portions 23 arranged inside of one second member folding portion 261 or third member folding portion 262 (that is, adjacent to each other in the X-axis direction) It is preferable that a sheet-like fourth member (member including the positive electrode (second electrode) 22) 26C be disposed between the matching first member folding portions 23). In the example shown in FIG. 13, the sheet-like fourth member 26 </ b> C is formed by covering the positive electrode 22 disposed between the first member folding parts 23 by the separator 25 from both sides.

  Further, in the storage element 1 according to the above-described embodiment, the second member 26A and the third member 26B are alternately stacked (arranged with respect to the plurality of first member folding portions 23 aligned in the X-axis direction) Is not limited to this configuration. The second member 26A and the third member 26B may be arranged at intervals of two, three, or more with respect to the plurality of first member folding portions 23 aligned in the X-axis direction. In addition, the second member 26A or the third member 26B may be disposed for each of the first member folding portions 23.

  The second member 26A and the third member 26B of the above embodiment have one folded portion (the second member folded portion 261, the third member folded portion 262), that is, the second member 26A and the third member Although 26B is comprised only by the 2nd member folding part 261 and the 3rd member folding part 262, it is not limited to this composition. The second member 26A and the third member 26B may have a plurality of (two in the example shown in FIG. 14) second member folded portions 261 or third member folded portions 262 as shown in FIG. In this case, although it is preferable that one first member folded portion 23 is disposed inside one second member folded portion 261 or third member folded portion 262, a plurality of first member folded portions 23 are disposed. It is also good.

  In the second member turn back portion 261 and the third member turn back portion 262 of the above embodiment, the direction-changing portions (the second member turn portion 261A, the third member turn portion 262B) are continuous portions in the turning direction. Not limited to this configuration. In the second member folding portion 261 and the third member folding portion 262, as shown in FIG. 15, the end portions of the plurality of sheet-like fifth members 26D are bundled together by the second member 26A and the third member 26B (connection As in the configuration, the configuration also includes a configuration in which the part (the second member turn portion 261A, the third member turn portion 262B) which is changing direction is not continuous in the turning direction.

  In the negative electrode (first member) 21 of the above embodiment, the negative electrode tab 235 extends from the two flat portions 233 arranged with the first member turn portion 234 interposed therebetween (see FIG. 8). It is not limited to this configuration. As shown in FIG. 16, the negative electrode tab 235A is an end edge of the first member turn portion 234 in the Z axis direction (in the example shown in FIG. 16, the end edge of the second first member turn portion 234B in the Z axis direction). It may extend in a bent state from the entire area). According to this configuration, since the negative electrode tab (extension piece) 235A extends in the Z-axis direction in a bent (curved) state, the strength of the negative electrode tab 235 is secured. In addition, in order to obtain this effect (securement of the mechanical strength of the negative electrode tab (extension piece) 235A), the second member folded portion 261 and the third member folded portion 262 of the above embodiment are necessarily required. It is not necessary to provide the member (In the example of the said embodiment, the 2nd member 26A, the 3rd member 26B). That is, in order to obtain the above effect, the first member (an example of the embodiment described above regardless of the presence or the configuration of the members 26A and 26B having the second member folded portion 261 and the third member folded portion 262 of the above embodiment. So long as the long side 210A of the main body 210 of the negative electrode 21) is extended from the end edge in the width direction of the first member turn 234A or the second first member turn 234B (ie, (If there is a member 21 shown in FIG. 16).

  Although the electrode body 2 of the said embodiment has one negative electrode (1st member) 21 of a zigzag state, it is not limited to this structure. The electrode assembly 2 may have a plurality of serpentine negative electrodes 21. In this case, for example, as shown in FIGS. 17 and 18, the first member folded portion 23 (the first first member folded portion 23A and the second one of the adjacent ones of the negative electrodes 21 (first members)) Of the first member folded portion 23B) and the first member folded portion 23 (the first first member folded portion 23A and the second first member folded portion) of the other negative electrode 21 of the adjacent negative electrodes 21 It is preferable that at least one of 23B is disposed inside the folded portion (the second member folded portion 261, the third member folded portion 262) of the common second member 26A or the third member 26B. According to this configuration, the portion connecting the negative electrodes (first members) 21 can be contributed to the charge and discharge of the storage element 1. In addition, a portion (first member folded portion 23 or a portion thereof) of each negative electrode (first member) 21 is a turn portion (second member turn portion 261A, third member turn of second member 26A, third member 26B) By directly or indirectly abutting on the inside of the portion 262B), the movement of the first member folding portions 23 (each of the plurality of negative electrodes 21) toward the second member 26A and the third member 26B is restricted. Misalignment of the plurality of first members 21 is suppressed. That is, the shift of the plurality of first members 21 is suppressed by the second member 26A and the third member 26B.

  Moreover, in the electrode body 2 of the said embodiment, although two types of members (2nd member 26A, 3rd member 26B) from which the protrusion position of the positive electrode tab 224 differs are arrange | positioned, it is not limited to this structure. In the electrode body 2, only one type of member (for example, the second member 26A) may be disposed. In this case, the positive electrode tabs 224 of the respective second members 26A are bundled at a plurality of locations in the Y-axis direction in the electrode body 2 (two locations in the case of only the second member 26A).

  For example, in the second member 26A, if the positive electrode tab (extension piece) 224 projects from the central position of one side (end edge) of the rectangular positive electrode main body (electrode main body) 223 (the 19), even if one type of member 26A is superimposed on both the first first member folded portion 23A and the second first member folded portion 23B, the positive electrode tabs 224 are bundled together in the electrode body 2 be able to.

  In the electrode body 2 of the above embodiment, the negative electrode 21 is in a zigzag state, that is, the first first member folding portion 23A and the second first member folding portion 23B are alternately continuous while sharing a part thereof with each other. Although arranged, it is not limited to this configuration. For example, as shown in FIG. 20, the electrode body 2 may have a plurality of first member folding portions 23 each formed of an independent negative electrode 21.

  In the electrode body 2 of the above embodiment, the second member turn portion 261, the second member turn portion 261A of the third member turn back portion 262, the third member turn portion 262B, and the first member turn portion of the first member turn portion 23 Although it is in direct contact with the H.234, it is not limited to this configuration. For example, in the electrode body 2, the second member turn back portion 261, the turn portions 261A and 262B of the third member turn back portion 262, and the first member turn portion 234 of the first member turn back portion 23 , Or may be in contact indirectly with another member such as a separator not included in any of the second member 26A and the third member 26B.

  Although the electrode body 2 of the said embodiment is comprised by the negative electrode (1st member) 21, 2nd member 26A, and 3rd member 26B, it is not limited to this structure. The electrode assembly 2 may have other components. For example, as shown in FIG. 21, the electrode body 2 may have a member overlapping with both end surfaces in the X axis direction of the negative electrode (first member) 21 in a zigzag state. That is, the electrode body 2 may have a member 26E having a folded portion 263 on which the whole of the negative electrode (first member) 21 in a zigzag state is disposed. The member 26E has a positive electrode 22 disposed at a position overlapping the both end surfaces of the serpentine negative electrode 21 and a separator 25 overlapping (covering) the positive electrode 22. Further, as shown in FIG. 22, the member 26E having the folded back portion 263 may be integral with the second member 26A or the third member 26B (in detail, integral in a state in which a part thereof is shared).

  In the electrode body 2 of the said embodiment, although a 1st member contains only the negative electrode 21 and does not contain a separator, it is not limited to this structure. The first member 21 may include the separator 25. That is, the first member may include the negative electrode 21 and the separator 25.

  In the electrode body 2 of the above embodiment, each of the constituent members (positive electrode 22 and separator 25) of the second member 26A and each of the constituent members (positive electrode 22 and separator 25) of the third member 26B have the same shape. Although it is, it is not limited to this composition. Each of the constituent members of the second member 26A and each of the constituent members of the third member 26B may have different shapes.

  In the electrode body 2 of the above embodiment, although the rectangular positive electrode tab 224 and the rectangular negative electrode tab 235 are arranged at both ends in the Y-axis direction, the present invention is not limited to this configuration. The shapes of the positive electrode tab 224 and the negative electrode tab 235 and the positions in the electrode body 2 can be changed as appropriate.

  In the storage element 1 of the above embodiment, the first electrode is the negative electrode 21, the second electrode is the positive electrode 22, and the third electrode is the positive electrode 22, but the present invention is not limited to this configuration. The first electrode may be a positive electrode, the second electrode may be a negative electrode, and the third electrode may be a negative electrode.

  In the electrode body 2 of the above embodiment, the particles contained in the particle layer of the separator 25 (in the example of the above embodiment, the inorganic layer) are inorganic particles, but the invention is not limited to this configuration. The particles contained in the particle layer of the separator 25 may be resin particles or the like formed of a resin such as polyethylene or polypropylene.

  In the above embodiment, although the case where the storage element is used as a chargeable / dischargeable non-aqueous electrolyte secondary battery (for example, lithium ion secondary battery) has been described, the type and size (capacity) of the 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, as well as storage devices of capacitors such as primary batteries and electric double layer capacitors.

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

  DESCRIPTION OF SYMBOLS 1 ... Storage element, 2 ... electrode body, 21 ... negative electrode (1st electrode, 1st member), 21A ... mountain fold line, 21B ... valley fold line, 210 ... main body, 210A ... long side, 211 ... metal foil, 212 negative electrode active material layer 22, 22A, 22B positive electrode (second electrode, third electrode) 221 metal foil 222 positive electrode active material layer 223 positive electrode main body 224 positive electrode tab 23 First member folded portion, 23A: first first member folded portion, 23B: second first member folded portion, 231, 231A, 231B: first surface, 232, 232A, 232B: second surface, 233, 233A, 233B: flat portion, 234: first member turn portion, 234A: first first member turn portion, 234B: second first member turn portion, 235, 235A: negative electrode tab (extension piece) , 25 ... separator, 26A ... second member 26B: third member, 26C: sheet-like fourth member, 26D: sheet-like fifth member, 26E: member having a folded portion 261: second member folded portion (folded portion), 261A: second member turn Part 262, third member folded part (folded part) 262B: third member turn part, 263: folded part, 3: case, 31: case main body, 310: opening peripheral part, 311: closed part, 312: barrel Parts, 313: long wall parts, 314: short wall parts, 32: cover plates, 4: external terminals, 5: current collectors, 6: insulation members, 11: storage devices, 12: bus bar members, 500: batteries, 501: ... Negative electrode plate (long electrode plate), 502: copper foil, 503: negative electrode active material layer, 504: positive electrode plate (strip electrode plate), 505: aluminum foil, 506: positive electrode active material layer, 507: separator, 508 ... integrated one-piece S ... pivot axis, α ... interval

Claims (6)

A first member including at least one folded portion including a first electrode and having a turn that is turned by the first member turn portion such that one side of the predetermined direction is opened, and one side of the predetermined direction is opened And a second member having a turn which is turned at the second member turn portion and including a second electrode different in polarity from the first electrode,
The first element turn portion is in direct or indirect contact with a valley fold side of the second element turn portion. A third member having a turnback portion turned by the third member turn portion so that the other side of the predetermined direction is opened, and including a third electrode of the same polarity as the second electrode,
The first member is opened at the first folded portion which is the folded portion which is turned by the first member turn portion which is the first member turn portion, and the other side of the predetermined direction is opened. As in the case of the serpentine state in which the second folded portion turning in the second first member turn portion is alternately disposed,
The storage element according to claim 1, wherein the second first member turn portion directly or indirectly abuts on a valley fold side of the third member turn portion. An electrode assembly having a plurality of first members and a second member;
Each of the plurality of first members includes at least one turnback portion including a first electrode and being turned at the first member turn portion so that one side in a predetermined direction is opened,
The second member includes a second electrode having a turn which is turned by the second member turn so that one side of the predetermined direction is opened, and including a second electrode different in polarity from the first electrode. ,
A storage element, wherein the folded portions of the plurality of first members respectively abut directly or indirectly on valley fold sides of the second member turn portions. The second member includes a plurality of second electrodes spaced apart from one another, and a separator superimposed on the plurality of second electrodes.
The interval is disposed at the second member turn portion,
The storage element according to any one of claims 1 to 3, wherein the turnback portion of the first member abuts directly or indirectly with respect to the region of the second member turn portion in which the gap is disposed. The separator comprises a substrate and a particle layer superimposed on the substrate,
The storage element according to claim 4, wherein the particle layer comprises particles and a binder.   The said 1st member has the extension piece extended in the said rotation axis direction in the state bent from the edge of the said 1st member turn part in the rotation axis direction of the said 1st member turn part, The any one of Claims 1-5 A storage element according to any one of the preceding items.

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