JP2016058393A - Power storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a short circuit due to the thermal shrinkage of a separator.SOLUTION: A secondary battery includes a layered electrode body 5 in a rectangular parallelepiped battery case can, the electrode body being formed by insulating between a positive electrode sheet 10 and a negative electrode sheet 11 with a separator 12 and by laminating these. A TD direction of the separator 12 is along a transverse direction in the front view of the battery case can.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a power storage device.

  A vehicle such as an EV (Electric Vehicle) or a PHV (Plug in Hybrid Vehicle) is equipped with a secondary battery such as a lithium ion battery as a power storage device that stores power supplied to an electric motor serving as a prime mover. This type of secondary battery is disclosed in Patent Document 1, for example. The secondary battery has an electrode body in which a negative electrode coated with a negative electrode active material and a positive electrode coated with a positive electrode active material are insulated with a separator made of a microporous film and laminated in layers.

JP-A-11-167934

  By the way, the separator which insulates between a positive electrode and a negative electrode is formed, for example with resin materials, such as a polypropylene. For this reason, when the internal temperature of the secondary battery rises for some reason and is heated excessively, the separator shrinks. And when a separator heat-shrinks, there exists a possibility that a positive electrode and a negative electrode may short-circuit.

  The present invention has been made paying attention to such problems, and an object thereof is to suppress a short circuit due to thermal contraction of the separator.

  A power storage device for solving the above-mentioned problems is a stacked electrode body in which a plurality of positive electrodes and a plurality of negative electrodes are alternately stacked in a state of being insulated from each other by a separator in a rectangular battery case. In the power storage device having the above, the gist is that the TD direction of the separator is along the short direction of the battery case in a front view when the battery case is viewed along the thickness direction of the separator.

  According to this, in the state where the TD direction of the separator is along the short direction of the battery case, the separator is difficult to be thermally contracted in the short direction of the battery case, and on the energization path along the short direction of the battery case. Therefore, it is possible to suppress the short-circuit between the positive electrode and the negative electrode.

  In addition, the power storage device includes a positive electrode terminal connected to the positive electrode and a negative electrode terminal connected to the negative electrode, and the separator is disposed in a protruding direction of the positive electrode terminal and the negative electrode terminal from the battery case. The TD direction is along.

  According to this, the energization path connecting the positive electrode and the positive electrode terminal, and the energization path connecting the negative electrode terminal and the negative electrode are along the TD direction of the separator. Since the separator is difficult to heat shrink in the TD direction, it is possible to suppress a short circuit between the positive electrode and the negative electrode on the energization path of each electrode.

  Moreover, about the electrical storage device, the positive electrode and the negative electrode have a terminal connection portion that protrudes along the TD direction of the separator, and the terminal connection portion of the positive electrode and the positive electrode terminal are electrically connected The terminal connection part of the negative electrode and the negative terminal are electrically connected.

  According to this, since the terminal connection part protrudes and forms in the edge part of an electrode, if a separator will heat-shrink, possibility that it will contact another electrode is high. For this reason, the short circuit of the positive electrode and the negative electrode can be suitably suppressed by forming the terminal connection portion along the TD direction.

In the power storage device, the terminal connection portions are collected in a range from one end to the other end in the stacking direction of the positive electrode and the negative electrode in the electrode body.
In the power storage device, the separator has a rectangular shape when viewed from the front along the thickness direction of the separator, and a short side of the separator in a short direction of the battery case in the front view of the battery case. The direction is along.

  Moreover, about an electrical storage apparatus, the insulating member is interposing between the end surface extended in the TD direction of the said some separator, and the inner surface of the said battery case can opposed to these end surfaces.

  According to the present invention, a short circuit due to thermal contraction of the separator can be suppressed.

The exploded perspective view of a secondary battery. The perspective view which shows the external appearance of a secondary battery. The disassembled perspective view which shows the component of an electrode body. Sectional drawing which shows the electrode body inserted in the battery case can. The side view of the electrode body seen from the arrow A direction of FIG. The side view which shows the electrode body of another example. (A) is a side view which shows the separator of another example, (b) is a front view which similarly shows the separator of another example.

Hereinafter, an embodiment embodying the present invention will be described with reference to FIGS.
As shown in FIGS. 1 and 2, in the secondary battery 2 as the power storage device, an electrode body 5 is accommodated in a metal battery case 3. The battery case 3 includes a rectangular parallelepiped main body member 4 and a rectangular flat lid member 6 that closes the opening 4 a of the main body member 4. Both the main body member 4 and the lid member 6 are made of metal (for example, stainless steel or aluminum). In addition, the secondary battery 2 of the present embodiment is a prismatic battery whose outer shell forms a square shape. Moreover, the secondary battery 2 of this embodiment is a lithium ion battery.

  A positive electrode terminal 7 and a negative electrode terminal 8 for taking out electricity from the electrode body 5 are electrically connected to the electrode body 5. The positive electrode terminal 7 and the negative electrode terminal 8 are exposed to the outside of the battery case 3 through a pair of opening holes 6 a arranged in parallel with the lid member 6 at a predetermined interval. Further, a ring-shaped insulating ring 9 a for insulating from the battery case can 3 is attached to the positive electrode terminal 7 and the negative electrode terminal 8, respectively. Further, as shown in FIG. 4, an insulating sheet 9b for insulating the metal main body member 4 and the electrode body 5 accommodated therein is attached to the inner surface of the main body member 4 constituting the battery case 3. It is worn. Further, as shown in FIG. 4, an insulating sheet 9c for insulating the metal lid member 6 and the electrode body 5 accommodated therein is attached to the inner surface of the lid member 6 constituting the battery case 3. It is worn.

  As shown in FIG. 3, the electrode body 5 includes a positive electrode sheet 10 that serves as a positive electrode and a negative electrode sheet 11 that serves as a negative electrode. The positive electrode sheet 10 has a positive electrode metal foil (aluminum foil in this embodiment) 13 and a positive electrode active material layer 14 formed by applying a positive electrode active material on both surfaces thereof. The negative electrode sheet 11 has a negative electrode metal foil (copper foil in this embodiment) 17 and a negative electrode active material layer 18 formed by applying a negative electrode active material on both surfaces thereof. And the electrode body 5 is made into the laminated body which makes | forms a layer form via the separator 12 as an insulating member which insulates between the positive electrode sheet 10 and the negative electrode sheet 11. For example, as shown in FIG. 5, the electrode body 5 is configured by laminating a plurality of positive electrode sheets 10 and a plurality of negative electrode sheets 11. That is, the electrode body 5 is provided with a plurality of sets each including the positive electrode sheet 10, the negative electrode sheet 11, and the separator 12.

  As shown in FIG. 3, a positive electrode tab-like portion 15 made of the positive electrode metal foil 13 is formed on a part of the edge of the positive electrode sheet 10. The positive electrode tab-like portion 15 has a positive electrode current collecting portion 16 that is a region where the positive electrode active material layer 14 is not applied. In the present embodiment, the positive electrode current collector 16 is the entire area of the positive electrode tab-like portion 15. In the present embodiment, the positive electrode current collector 16 is formed at the edge of the positive electrode sheet 10. Further, the positive electrode tab-like portion 15 and the positive electrode current collector portion 16 are formed in the same shape at the same position in each positive electrode sheet 10 constituting the electrode body 5.

  A negative electrode tab-like portion 19 made of the negative electrode metal foil 17 is formed on a part of the edge of the negative electrode sheet 11. The negative electrode tab-like portion 19 has a negative electrode current collector 20 that is a region where the negative electrode active material layer 18 is not applied. In the present embodiment, the negative electrode current collector 20 is the entire area of the negative electrode tab-like part 19. In the present embodiment, the negative electrode current collector 20 is formed at the edge of the negative electrode sheet 11. Further, the negative electrode tab-like portion 19 and the negative electrode current collector 20 are formed in the same position and in the same shape in each negative electrode sheet 11 constituting the electrode body 5. In the positive electrode sheet 10 and the negative electrode sheet 11, a region where the active material is applied becomes a coated portion, and a region where the active material is not applied becomes an uncoated portion.

  Each positive electrode sheet 10 constituting the electrode body 5 is laminated so that the respective positive electrode current collectors 16 are arranged in a line along the lamination direction. Similarly, each negative electrode sheet 11 constituting the electrode body 5 is laminated such that the respective negative electrode current collectors 20 are arranged in a row along the lamination direction so as not to overlap the positive electrode current collectors 16. . And each positive electrode current collection part 16 is collected in the range from the one end of the lamination direction in the electrode body 5 to the other end, and is made into the positive electrode current collection group 21, as shown in FIG. Similarly, each of the negative electrode current collectors 20 is also collected in a range from one end to the other end in the stacking direction of the electrode body 5 as shown in FIG.

  The positive electrode terminal 7 is electrically joined to the positive electrode current collecting group 21. On the other hand, the negative electrode terminal 8 is electrically connected to the negative electrode current collecting group 22. The positive electrode terminal 7 and the negative electrode terminal 8 are joined to the positive electrode current collection group 21 and the negative electrode current collection group 22 by resistance welding. Resistance welding is a method in which the objects to be joined are welded by sandwiching a pair of positive and negative electrodes for welding. In the present embodiment, the positive electrode current collection group 21 and the negative electrode current collection group 22 serve as terminal connection parts, and the terminal connection part is configured by the positive electrode current collection part 16 of each positive electrode sheet 10 and the negative electrode current collection part 20 of each negative electrode sheet 11. The

Hereinafter, the positive electrode sheet 10, the negative electrode sheet 11, and the separator 12 that constitute the electrode body 5 of the present embodiment will be described in more detail.
As shown in FIG. 3, each of the positive electrode sheet 10, the negative electrode sheet 11, and the separator 12 is formed in a rectangular shape (rectangular shape) when viewed from the front. In the present embodiment, the lengths of the separator 12 in the longitudinal direction and the short direction are formed larger than the lengths of the positive electrode sheet 10 and the negative electrode sheet 11 in the longitudinal direction and the short direction, respectively. In the present embodiment, the separator 12 is a polyolefin microporous separator. Specifically, the separator 12 is formed of polyethylene (PE), polypropylene (PP), polyethylene teleflator (PET), or the like. The thickness of the separator 12 is set to about 20 μm.

  The separator 12 is manufactured by cutting a separator raw material into a desired size. The separator original fabric is manufactured by obtaining a step of forming pores of a predetermined porosity simultaneously with stretching of the separator material or in a step different from stretching. Thereby, as for the separator 12, the fiber is orientating in the machine direction at the time of manufacture, ie, MD direction. For this reason, the separator 12 is easy to heat-shrink to MD direction compared with TD direction orthogonal to MD direction. That is, the separator 12 has a larger amount of heat shrinkage in the MD direction than the amount of heat shrinkage in the TD direction.

  A plurality of separators 12 are used for the electrode body 5. As shown in FIG. 3, each separator 12 is formed in a rectangular shape in front view with the MD direction as the longitudinal direction. And the thermosetting resin member 28 is joined to the two end surfaces 12a and 12b along the MD direction of each separator 12, respectively. The thermosetting resin member 28 is made of a thermosetting resin that is cured at a temperature lower than the heat shrinkage temperature of the separator 12. Thermosetting resins include epoxy resin (EP), phenol resin (PF), melamine resin (MF), urea resin (UF), unsaturated polyester resin (UP), alkyd resin, polyurethane (PUR), polyimide (PI) ) Etc. are used.

  The thermosetting resin member 28 has a region around the edges of the end faces 12a and 12b on the entire area of the end faces 12a and 12b along the MD direction of the separator 12 and both front and back faces (two faces) facing the separator 12 in the thickness direction. Each is formed as a resin layer coated with a thermosetting resin. The thermosetting resin is applied almost linearly to each of the above regions. Thereby, as shown in FIGS. 3 and 5, the thermosetting resin member 28 includes a rectangular plate-like joint portion 29 that covers the entire area of the end faces 12 a and 12 b along the MD direction of the separator 12, and a short portion of the joint portion 29. A pair of connecting portions 30 that extend in the same direction from the end portions in the hand direction and cover a region around the edge portions of the end faces 12a and 12b are configured. That is, the thermosetting resin member 28 has a U-shape (or a front-view concave shape) having an opening between the connecting portions 30 by extending the connecting portions 30 on both sides of the joint portion 29. End faces 12 a and 12 b along the MD direction of the separator 12 are surrounded by a thermosetting resin member 28 including a joint portion 29 and a connecting portion 30. In the present embodiment, the joint portion 29 and the connecting portion 30 are continuously formed along the MD direction.

  The length in the longitudinal direction of the joint portion 29 in the thermosetting resin member 28 is the same as the length in the longitudinal direction along the MD direction of the separator 12. The length of the opening formed in the thermosetting resin member 28 is the same as the length of the separator 12 in the longitudinal direction along the MD direction. The width of the opening is the same length as the thickness of the separator 12.

  Thus, the separator 12 joined with the thermosetting resin member 28 is interposed between the positive electrode sheet 10 and the negative electrode sheet 11 as shown in FIG. Specifically, each positive electrode sheet 10, each negative electrode sheet 11, and each separator 12 are laminated such that their longitudinal directions coincide with each other, as shown in FIGS. Thereby, when the electrode body 5 is configured, the positive electrode current collecting group 21 including the positive electrode current collecting unit 16 and the negative electrode current collecting group 22 including the negative electrode current collecting unit 20 are arranged along the MD direction of the separator 12. Moreover, each positive electrode current collection part 16 of the positive electrode sheet 10 protrudes from the edge part along the longitudinal direction of the positive electrode sheet 10 along the transversal direction. Similarly, each negative electrode current collector 20 of the negative electrode sheet 11 protrudes from the edge portion along the longitudinal direction of the negative electrode sheet 11 along the short direction. For this reason, when the electrode body 5 is configured, the positive electrode current collector 16 and the negative electrode current collector 20 protrude along the TD direction of the separator 12. That is, the positive electrode current collector 16 and the negative electrode current collector 20 are formed on each of the positive electrode sheet 10 and the negative electrode sheet 11 so as to protrude in the TD direction of the separator 12.

Hereinafter, the operation of the secondary battery 2 of the present embodiment will be described.
The thermosetting resin member 28 is cured at a temperature lower than the heat shrink temperature of the separator 12. For this reason, even if the internal temperature of the secondary battery 2 rises and the internal temperature reaches the thermal contraction temperature of the separator 12, according to the configuration of the secondary battery 2 of the present embodiment, the contraction of the separator 12 occurs. Before that, the thermosetting resin constituting the thermosetting resin member 28 is cured. That is, the thermosetting resin member 28 is made rigid by the temperature rise and increases in strength. Accordingly, the thermosetting resin member 28 is disposed along the MD direction of the separator 12 having a large amount of heat shrinkage, thereby resisting the heat shrinkage force of the separator 12 and preventing the separator 12 from being deformed. The sheet-like separator 12 is supported by a force that resists the thermal contraction force by the thermosetting resin member 28 having increased strength due to curing acting as a frame. Accordingly, the separator 12 is prevented from being deformed in the MD direction by the thermosetting resin member 28 even when the internal temperature reaches the heat shrinkage temperature.

  When the separator 12 is thermally contracted greatly in the MD direction, the electrode body 5 is more likely to be short-circuited between the positive electrode sheet 10 and the negative electrode sheet 11 facing each other with the separator 12 interposed therebetween. However, in this embodiment, the positive electrode sheet 10 and the negative electrode sheet 11 are short-circuited even when the internal temperature of the secondary battery 2 is increased by suppressing the thermal contraction of the separator 12 by the thermosetting resin member 28. The possibility of doing so is extremely low.

  In the present embodiment, the positive electrode current collector 16 and the negative electrode current collector 20 are protruded in the TD direction, which is less likely to be thermally contracted than in the MD direction. When the positive electrode current collector 16 and the negative electrode current collector 20 are protruded in the MD direction, if the separator 12 is thermally contracted, there is a high possibility that the protruded current collector is short-circuited with other electrodes. For this reason, in this embodiment, the positive electrode current collector 16 and the negative electrode current collector 20 are provided so as to protrude in the TD direction, which is unlikely to be thermally contracted in the separator 12, so that the positive electrode sheet 10 and the negative electrode sheet 11 are short-circuited. The possibility of endangering is extremely low.

  Further, when the secondary battery 2 of the present embodiment is mounted on a vehicle, the possibility that the positive electrode sheet 10 and the negative electrode sheet 11 are short-circuited is extremely low, so that the influence on the running performance of the vehicle is reduced. . That is, the reliability of vehicle travel is improved.

  The thermosetting resin constituting the thermosetting resin member 28 is applied before the separator 12 is manufactured, that is, before the electrode body 5 is formed. When polyimide is employed as the thermosetting resin, it is applied at the stage of manufacturing the separator 12 and then heated at a temperature equal to or higher than the boiling point of the solvent to evaporate the solvent. As a result, when the thermosetting resin is polyimide, it is already cured at the manufacturing stage. That is, even when polyimide is used as the thermosetting resin, it is cured when the internal temperature of the secondary battery 2 reaches the thermal contraction temperature of the separator 12, so that deformation of the separator 12 can be suppressed. it can. In addition, when an epoxy resin etc. are employ | adopted as a thermosetting resin, these resin hardens | cures when the internal temperature of the secondary battery 2 reaches the curing temperature. And since these resin hardens | cures at temperature lower than the heat shrink temperature of the separator 12, the deformation | transformation of the separator 12 can be suppressed.

  The thickness α of the connecting portion 30 of the thermosetting resin member 28 shown in FIG. 5 is the thinner of the thickness of the positive electrode active material layer 14 of the positive electrode sheet 10 and the thickness of the negative electrode active material layer 18 of the negative electrode sheet 11. The maximum thickness is set to about one half of the thickness. In addition, the thickness β of the joint portion 29 of the thermosetting resin member 28 is set so as to have a cross-sectional area that can resist the contraction force of the separator 12. When the thermosetting resin member 28 has the connecting portion 30, the length γ from the edge of the end faces 12 a and 12 b of the separator 12 in the connecting portion 30 is determined between the positive electrode sheet 10 and the negative electrode sheet interposed between the separators 12. 11 is set according to the size. That is, if the length γ is increased so that the connecting portion 30 of the thermosetting resin member 28 is interposed between the positive electrode sheet 10 or the negative electrode sheet 11 and the separator 12, the connecting portion 30 inhibits ion permeation. For this reason, the length γ of the connecting portion 30 is set such that the length from the end face of the positive electrode sheet 10 or the negative electrode sheet 11 adjacent to the separator 12 to the end faces 12a and 12b of the separator 12 is the maximum length.

Therefore, according to the present embodiment, the following effects can be obtained.
(1) The thermosetting resin member 28 was joined to the end faces 12a and 12b along the MD direction of the separator 12. According to this, even when the separator 12 is excessively heated as the internal temperature of the secondary battery 2 increases, the heat of the separator 12 is heated by the thermosetting resin member 28 bonded in the MD direction of the separator 12. Shrinkage is suppressed. That is, the thermosetting resin member 28 is cured at a temperature lower than the heat shrinkage temperature of the separator 12, so that the thermosetting resin member 28 is already cured and increases in strength when the separator 12 reaches the heat shrinkage temperature. For this reason, the separator 12 is supported by the force that resists the thermal contraction force by the thermosetting resin member 28. Therefore, even when the separator 12 is heated until reaching the heat shrinkage temperature, the thermosetting resin member 28 suppresses the heat shrinkage in the MD direction. As a result, the secondary battery 2 is unlikely to short-circuit between the positive electrode sheet 10 and the negative electrode sheet 11, and function deterioration is suppressed.

  (2) In addition, the thermosetting resin member 28 is composed of a joint portion 29 and a connecting portion 30. And the connection part 30 contacts both surfaces of the thickness direction of the separator 12, and is joined. According to this, the separator 12 is supported by a stronger force by joining the thermosetting resin member 28 to both surfaces in the thickness direction of the separator 12 in addition to the end faces 12a and 12b along the MD direction. Become. Therefore, the thermal contraction of the separator 12 can be more reliably suppressed.

  (3) Moreover, the junction part 29 is continuously formed along MD direction. When the joining portion 29 is formed intermittently (when formed at intervals), thermal contraction in the MD direction of the separator 12 is allowed at a portion where the thermosetting resin member 28 is not joined. However, the thermal contraction of the separator 12 can be reliably suppressed by continuously forming the joint portion 29.

  (4) As a configuration for suppressing the thermal shrinkage of the separator 12, a configuration in which a thermosetting resin is applied to the end faces 12a and 12b of the separator 12 is employed. For this reason, the space occupied by the thermosetting resin member 28 in the secondary battery 2 does not increase. Therefore, the physique (size) of the secondary battery 2 does not become extremely large, and the application amount of the active material layer does not decrease. Moreover, it can suppress that a dead space increases in the secondary battery 2. FIG.

  (5) A positive electrode current collector 16 (positive electrode current collector group 21) and a negative electrode current collector 20 (negative electrode current collector group 22) were formed along the TD direction of the separator 12. The TD direction of the separator 12 is less likely to heat shrink than the MD direction. For this reason, even if it is a case where the separator 12 is heated until it reaches heat contraction temperature, the short circuit of the positive electrode sheet 10 and the negative electrode sheet 11 can be suppressed suitably. In particular, the positive electrode current collector 16 (positive electrode current collector group 21) and the negative electrode current collector part 20 (negative electrode current collector group 22) are formed so as to protrude from the edge of the electrode, so that the separator 12 is thermally contracted. And there is a high possibility of contact with other electrodes. For this reason, the short circuit of the positive electrode sheet 10 and the negative electrode sheet 11 can be suitably suppressed by forming along the TD direction.

  (6) If the thermosetting resin member 28 is formed of an epoxy resin that hardens as the internal temperature of the secondary battery 2 increases, the thermosetting resin member 28 is cured when the electrode body 5 is manufactured. It can be in a state that is not. Therefore, the production of the electrode body 5 is not hindered.

  (7) In addition, when the secondary battery 2 of the present embodiment is mounted on a vehicle, the possibility that the positive electrode sheet 10 and the negative electrode sheet 11 are short-circuited is extremely low, thereby affecting the running performance of the vehicle. Becomes smaller. Therefore, the reliability of vehicle travel can be improved.

In addition, you may change the said embodiment as follows.
As shown in FIG. 6, the thermosetting resin member 28 may be bonded only to the end faces 12 a and 12 b of the separator 12.

  As shown in FIGS. 7A and 7B, the connecting portion 30 of the thermosetting resin member 28 may be intermittently joined. That is, the thermosetting resin member 28 (the connecting portion 30) is intermittently bonded to two surfaces (both surfaces) opposed in the thickness direction of the separator 12. On the other hand, the thermosetting resin member 28 (joining part 29) is joined to the end faces 12a and 12b of the separator 12 in the same manner as in the embodiment, that is, continuously.

  (Circle) you may form the positive electrode sheet 10, the negative electrode sheet 11, and the separator 12 in the front view square. Also in this case, the thermosetting resin member 28 is joined to the end faces 12a and 12b along the MD direction of the separator 12.

The thermosetting resin member 28 may be bonded to the separator 12 by heat welding or may be bonded with an adhesive.
(Circle) the connection part 30 should just be in contact with both surfaces of the thickness direction of the separator 12. FIG. That is, the connecting portion 30 may be bonded to the separator 12 or may not be bonded. By keeping the connecting portion 30 in contact, the connecting portion 30 can serve as a resistance when the separator 12 together with the joint portion 29 is thermally contracted in the MD direction. Further, the connecting portion 30 may be provided so as to be in contact with either one of the two surfaces in the thickness direction of the separator 12, that is, one surface.

The positive electrode current collector 16 and the negative electrode current collector 20 may be disposed along the TD direction of the separator 12 and may protrude along the MD direction.
○ Although the insulating sheet 9b is attached to the inside of the battery case 3, the thermosetting resin member 28 has an insulating property, so that the inner surface of the battery case 3 facing the connecting portion of the thermosetting resin member 28 The insulating sheet 9b may not be attached. That is, the thermosetting resin member 28 may be used as an insulating member that insulates the battery case 3 and the electrode body 5.

  The bonding mode of the positive electrode current collector 16 (positive electrode current collector group 21) and the negative electrode current collector 20 (negative electrode current collector group 22), the positive electrode terminal 7 and the negative electrode terminal 8 is not limited to the configuration of the embodiment, and is arbitrarily selected. It may be changed. For example, the positive electrode current collector 16 and the negative electrode current collector 20 may be joined to the positive electrode terminal 7 and the negative electrode terminal 8 without forming the current collection group. Further, the number of current collecting groups formed in the electrode body 5 and the shapes of the positive electrode terminal 7 and the negative electrode terminal 8 may be arbitrarily changed.

O After configuring the electrode body 5, the thermosetting resin member 28 may be bonded to the separator 12.
The vehicle on which the secondary battery 2 of the embodiment is mounted may be an automobile or an industrial vehicle.

The configuration of the present embodiment may be applied to other power storage devices such as electric double layer capacitors.
The secondary battery 2 is a lithium ion secondary battery, but is not limited thereto, and may be another secondary battery. In short, any material may be used as long as ions move between the active material layer for the positive electrode and the active material layer for the negative electrode and charge is transferred.

Next, a technical idea that can be grasped from the above embodiment and another example will be added below.
(A) A vehicle that travels by supplying electric power stored in a power storage device to an electric motor, wherein the power storage device is mounted as the power storage device.

  2 ... secondary battery, 3 ... battery case can, 5 ... electrode body, 7 ... positive electrode terminal, 8 ... negative electrode terminal, 10 ... positive electrode sheet, 11 ... negative electrode sheet, 12 ... separator, 16 ... positive electrode current collector, 20 ... Negative electrode current collector, 21 ... positive electrode current collector group, 22 ... negative electrode current collector group.

Claims (6)

In a power storage device having a stacked electrode body, which is alternately stacked in a state where a plurality of positive electrodes and a plurality of negative electrodes are insulated from each other by a separator, in a rectangular battery case,
The power storage device according to claim 1, wherein in a front view when the battery case can is viewed along the thickness direction of the separator, a TD direction of the separator is along a short direction of the battery case.   It has a positive electrode terminal connected to the positive electrode and a negative electrode terminal connected to the negative electrode, and the TD direction of the separator is along the protruding direction of the positive electrode terminal and the negative electrode terminal from the battery case. The power storage device according to claim 1.   The positive electrode and the negative electrode have a terminal connection portion that protrudes along the TD direction of the separator, the terminal connection portion of the positive electrode and the positive electrode terminal are electrically connected, and the negative electrode The power storage device according to claim 2, wherein the terminal connection portion and the negative electrode terminal are electrically connected.   The power storage device according to claim 3, wherein the terminal connection portions are gathered in a range from one end to the other end in the stacking direction of the positive electrode and the negative electrode in the electrode body.   The separator is rectangular when viewed from the thickness direction of the separator, and the short direction of the separator is along the short direction of the battery can in the front view of the battery can. The power storage device according to claim 4.   The insulating member is interposed between the end surfaces extending in the TD direction of the plurality of separators and the inner surface of the battery case that faces the end surfaces. The power storage device according to claim 1.

Images