JP2021111500A - Power storage element - Google Patents

Abstract

To provide a power storage element improved in accuracy of an arrangement position in arranging a power storage element, when a power storage module is assembled.SOLUTION: In the present embodiment, a power storage element includes: an electrode body; a case 3 including a case body 4 having an opening 40 and a lid plate 5 covering the opening 40, the case housing the electrode body therein; an external terminal 6 disposed on the external surface 50 of the lid plate 5 and electrically connected to the electrode body; and an index part 7 disposed on the external surface 50 of the lid plate 5 and disposed at a position different from the external terminal 6, the index part 7 being at least one of a recessed part recessed to the inside of the case 3 and a projecting part projecting to the outside of the case 3.SELECTED DRAWING: Figure 1

Description

The present invention relates to a power storage element including an electrode body, a case body for accommodating the electrode body, and a case including a lid plate covering an opening of the case body.

Conventionally, a secondary battery including an electrode body, a can body accommodating the electrode body, and a battery can composed of a sealing plate covering an opening of the can body is known (see, for example, Patent Document 1). Specifically, as shown in FIG. 8, the secondary battery is composed of an electrode body 102, a can body 111 accommodating the electrode body 102, and a sealing plate 112 welded to an opening of the can body 111. It is equipped with a battery can.

Japanese Unexamined Patent Publication No. 2005-142026

By the way, when assembling a power storage device including a plurality of such secondary batteries, when arranging the secondary batteries, the secondary batteries are grasped and moved with the sealing plate 112 sandwiched from both sides by a jig or the like. , It is conceivable to arrange the secondary batteries in appropriate positions. On the other hand, since higher accuracy is required when manufacturing the power storage device, it is required to improve the accuracy of the placement position when arranging the secondary battery when assembling the power storage device.

Therefore, an object of the present embodiment is to provide a power storage element having improved accuracy of the placement position when arranging the power storage element when assembling the power storage module.

The power storage element of this embodiment is
With the electrode body
A case body having an opening, a case including a lid plate covering the opening, and a case for accommodating the electrode body.
An external terminal arranged on the outer surface of the lid plate and electrically connected to the electrode body,
An index unit arranged on the outer surface of the lid plate and arranged at a position different from that of the external terminal is provided.
The index portion is at least one of a concave portion recessed inside the case and a convex portion protruding outward from the case.

According to this configuration, when arranging the power storage element when assembling the power storage module, the power storage element can be positioned with reference to the index unit, so that the accuracy of the placement position of the power storage element when assembling the power storage module is improved. Can be made to.

In the power storage device,
The index portion may have a circular shape when viewed from the thickness direction of the lid plate.

According to such a configuration, since the index unit can be easily recognized, it can be easily used for positioning the power storage element. In addition, it is possible to prevent the stress from being partially concentrated on the index portion.

In the power storage device,
The external terminal projects to the outside of the case and
The index portion may be smaller than the external terminal when viewed from the thickness direction of the lid plate.

In the power storage device,
The external terminals include positive electrode terminals and negative electrode terminals arranged on the outer surface of the lid plate at intervals from each other.
The index portion is a positive electrode side index portion arranged on the positive electrode terminal side of the outer surface of the lid plate with respect to the central portion of the positive electrode terminal and the negative electrode terminal, and the center of the positive electrode terminal and the negative electrode terminal. Including a negative electrode side index portion arranged on the negative electrode terminal side of the portion,
The shape of the positive electrode side index portion may be different from the shape of the negative electrode side index portion.

According to such a configuration, it is easy to distinguish between the positive electrode terminal and the negative electrode terminal of the power storage element due to the difference in shape between the positive electrode side index portion and the negative electrode side index portion. That is, it is possible to discriminate between the positive electrode and the negative electrode by using the portion that is the index of positioning, and by forming the portion that is the index of positioning in such a shape, the discrimination between the positive electrode and the negative electrode becomes the index of positioning. It is easy because it is possible from the appearance of the part.

In the power storage device,
The external terminals include positive electrode terminals and negative electrode terminals arranged on the outer surface of the lid plate at intervals from each other.
The index portion is a positive electrode side index portion arranged on the positive electrode terminal side of the outer surface of the lid plate with respect to the central portion of the positive electrode terminal and the negative electrode terminal and displaying information on the positive electrode, and the positive electrode terminal. And the negative electrode side index portion which is arranged on the negative electrode terminal side from the central portion of the negative electrode terminal and where information about the negative electrode is displayed may be included.

According to such a configuration, it is easy to distinguish between the positive electrode terminal and the negative electrode terminal of the power storage element based on the information displayed on the positive electrode side index unit and the negative electrode side index unit. In addition, it is easy to understand the information for distinguishing the positive electrode and the negative electrode.

In the power storage device,
The lid plate has a joint portion to be joined to the opening edge of the case body, and a protrusion portion protruding inward of the case body from a portion adjacent to the joint portion.
The protrusion may have an inclined surface that is inclined so that the portion located on the protruding side is farther from the opening edge of the case body.

According to such a configuration, even if the position of the lid plate with respect to the case body is slightly deviated when assembling the power storage element, the lid plate is likely to be inserted into the case body along the inclined surface of the protrusion.

According to the power storage device of the present embodiment, it is an object of the present invention to provide a power storage element having improved accuracy of the placement position when arranging the power storage element when assembling the power storage module.

FIG. 1 is a perspective view of a power storage element according to the present embodiment. FIG. 2 is a side view of the power storage element. FIG. 3 is a plan view of the power storage element. FIG. 4 is a cross-sectional view of the power storage element at the IV-IV position. FIG. 5 is an enlarged view in the V region of FIG. FIG. 6 is a perspective view of a power storage device including the power storage element. FIG. 7 is a perspective view of the power storage element according to the modified example. FIG. 8 is a perspective view for explaining a conventional power storage element.

Hereinafter, an embodiment of the power storage element according to the present invention will be described with reference to FIGS. 1 to 5. The power storage element includes a primary battery, a secondary battery, a capacitor, and the like. In the present embodiment, a rechargeable secondary battery will be described as an example of the power storage element. The name of each component (each component) of the present embodiment is that of the present embodiment, and may be different from the name of each component (each component) in the background technology.

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

The power storage element is a primary battery, a secondary battery, a capacitor, or the like. The power storage element 1 of the present embodiment is a non-aqueous electrolyte secondary battery that can be charged and discharged. More specifically, the power storage element is a lithium ion secondary battery that utilizes electron transfer generated by the movement of lithium ions. The power storage element 1 is a so-called square lithium ion secondary battery.

As shown in FIGS. 1 to 4, the power storage element 1 includes an electrode body 2, a case body 4 having an opening 40, and a lid plate 5 covering the opening 40, and a case 3 accommodating the electrode body 2. , An external terminal 6 arranged on the outer surface 50 of the lid plate 5 and electrically connected to the electrode body 2, and an index unit arranged on the outer surface 50 of the lid plate 5 and arranged at a position different from the external terminal 6. 7 and. The power storage element 1 of the present embodiment includes a current collector 8 and the like for conducting the electrode body 2 and the external terminal 6 in addition to the electrode body 2, the case 3, and the external terminal 6.

The electrode body 2 includes a winding core 21 and a laminated body 22 in which a positive electrode and a negative electrode are laminated so as to be insulated from each other, and the laminated body 22 is wound around the winding core 21 (FIG. FIG. 4). Lithium ions move between the positive electrode and the negative electrode in the electrode body 2, so that the power storage element 1 is charged and discharged.

The positive electrode has, for example, a strip-shaped metal foil and a positive electrode active material layer formed on the metal foil. The negative electrode has, for example, a strip-shaped metal foil and a negative electrode active material layer formed on the metal foil.

In the electrode body 2 of the present embodiment, the positive electrode and the negative electrode are wound in a state of being insulated by the separator. That is, in the electrode body 2 of the present embodiment, the laminated body of the positive electrode, the negative electrode, and the separator is wound. The separator is a member having an insulating property. The separator is arranged between the positive electrode and the negative electrode. As a result, in the electrode body 2 (specifically, the laminated body), the positive electrode and the negative electrode are insulated from each other. Further, the separator holds the electrolytic solution in the case 3. As a result, during charging and discharging of the power storage element 1, lithium ions move between the positive electrode and the negative electrode which are alternately laminated with the separator in between.

The case 3 houses the electrolytic solution in the internal space together with the electrode body 2 and the current collector 8. Further, the case 3 has, for example, a flat rectangular parallelepiped shape (see FIG. 1). The case 3 is formed of a metal that is resistant to the electrolytic solution. Case 3 of the present embodiment is formed of, for example, aluminum or an aluminum-based metal material such as an aluminum alloy. The case 3 may be formed of a metal material such as stainless steel and nickel, or a composite material in which a resin such as nylon is adhered to aluminum.

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

The case 3 is formed by joining the opening edge 41 of the case body 4 and the joint portion 51 of the lid plate 5 in a superposed state (see FIG. 4). The joint portion 51 is a portion of the lid plate 5 that is joined to the opening edge 41. Further, the case 3 has an internal space 30 defined by the case main body 4 and the lid plate 5. In the present embodiment, the opening edge 41 of the case body 4 and the joint portion 51 of the lid plate 5 are joined by welding.

The case body 4 is a plate-shaped closing portion 42 having an inner surface facing the inside of the case 3 and an outer surface facing the outside of the case 3, and a body portion 43 connected to the peripheral edge of the closing portion 42. It is provided with a tubular body portion 43 extending toward the inner surface side of the closing portion 42 and surrounding the inner surface.

The closing portion 42 is located at the lower end of the case main body 4 when the case main body 4 is arranged so that the opening 40 faces upward (that is, the bottom wall of the case main body 4 when the opening faces upward). Is the part. Further, the closed portion 42 has a rectangular shape in the normal direction of the closed portion 42. The four corners of the closing portion 42 are arcuate.

In the following, as shown in FIG. 1, the long side direction of the closed portion 42 is the X-axis direction, the short side direction of the closed portion 42 is the Y-axis direction, and the normal direction of the closed portion 42 is the Z-axis direction.

The body portion 43 of the present embodiment has a square tubular shape. Specifically, the body portion 43 has a flat square tube shape. The body portion 43 has a pair of long wall portions 431 extending from the long side at the peripheral edge of the closing portion 42, and a pair of short wall portions 432 extending from the short side at the peripheral edge of the closing portion 42. That is, the pair of long wall portions 431 face each other with an interval in the Y-axis direction (specifically, the interval corresponding to the short side at the peripheral edge of the closed portion 42), and the pair of short wall portions 432 are spaced in the X-axis direction. (Specifically, they face each other with an interval corresponding to the long side at the peripheral edge of the closed portion 42). A square tubular body portion 43 is formed by connecting the ends of the pair of long wall portions 431 that correspond to each other (specifically, facing each other in the Y-axis direction).

As described above, the case body 4 has a square tube shape (that is, a bottomed square tube shape) in which one end in the opening direction (Z-axis direction) is closed.

The lid plate 5 is a plate-shaped member that closes the opening of the case body 4. Specifically, the lid plate 5 comes into contact with the case body 4 so as to close the opening 40 of the case body 4. More specifically, the joint portion 51 of the lid plate 5 is overlapped with the opening edge 41 of the case body 4 so that the lid plate 5 closes the opening. The boundary between the lid plate 5 and the case body 4 is welded in a state where the opening edge 41 and the joint portion 51 are overlapped with each other. As a result, the case 3 is configured.

The lid plate 5 has a contour shape corresponding to the opening edge 41 of the case body 4 when viewed in the Z-axis direction. That is, the lid plate 5 is a rectangular plate material that is long in the X-axis direction when viewed in the Z-axis direction. The four corners of the lid plate 5 are arcuate.

As shown in FIG. 5, the lid plate 5 of the present embodiment is formed from the above-mentioned joint portion 51 (the joint portion 51 that joins with the opening edge 41 that is the opening edge of the case body 4) and the portion adjacent to the joint portion 51. It has a protrusion 52 that projects inward of the case body 4.

The joint portion 51 is composed of an outer peripheral portion of the lid plate 5. The joint portion 51 of the present embodiment is continuously arranged in the circumferential direction of the outer peripheral portion of the lid plate 5.

The protrusion 52 of the present embodiment is a protrusion. Further, a pair of protrusions 52 are provided on the lid plate 5. Specifically, the protrusions 52 are provided at both ends of the lid plate 5 in the X-axis direction. More specifically, each protrusion 52 extends along the short side of the lid plate 5 and extends along a pair of corners of the lid plate 5 arranged in the Y-axis direction.

Further, the protrusion 52 has an inclined surface 520 that is inclined so that the portion located on the protruding side is farther from the opening edge 41 of the case body 4. In the protrusion 52 of the present embodiment, the entire outer peripheral surface of the protrusion 52 is an inclined surface 520, but at least a part of the outer peripheral surface of the protrusion 52 may be an inclined surface 520. Further, the protrusion 52 of the present embodiment has a shape in which the width becomes narrower toward a portion located on the protruding side in the Y-axis direction view.

The inclined surface 520 is linear in the Y-axis direction, but may be curved (curved surface) in the Y-axis direction. When the inclined surface 520 is curved in the Y-axis direction, it may be curved so as to bulge toward the outside of the case body 4, or it may be curved toward the inside of the case body 4. May be good. The angle θ formed by the inclined surface 520 and the inner surface 53 of the lid plate 5 is, for example, 50 ° or more and 60 ° or less, for example, 55 °. By setting the angle θ formed by the inclined surface 520 and the inner surface 53 of the lid plate 5 to 50 ° or more and 60 ° or less, the dimensions of the inclined surface 520 in the X-axis direction are secured, and the case body 4 and the lid plate 5 are connected to each other. In addition to facilitating positioning, the lid plate 5 can be easily inserted into the case body 4. Further, the angle θ formed by the inclined surface 520 and the inner surface 53 of the lid plate 5 is the same at any portion in the protruding direction (Z-axis direction), for example.

Further, the protrusion 52 is formed by a coining process. That is, the protrusion 52 is a portion in which the outer surface 50 (outer surface) side of the lid plate 5 is recessed in a concave shape and the inner surface 53 (inner surface) side of the lid plate 5 is raised in a convex shape. As a result, the lid plate 5 of the present embodiment has a recessed position 55.

The recessed position 55 is a portion corresponding to the position of the inner surface 53 of the lid plate 5 on which the protrusion 52 is formed. For example, the volume of the recessed position 55 recessing the outer surface 50 of the lid plate 5 is substantially the same as the volume of the protrusion 52 raised from the inner surface 53 of the lid plate 5. Further, for example, the area of the recessed position 55 in the Z-axis direction is larger than the area of the protrusion 52 in the Z-axis direction.

The lid plate 5 of the present embodiment has a gas discharge valve 56 capable of discharging the gas in the case 3 to the outside. The gas discharge valve 56 discharges gas from the inside of the case 3 to the outside when the internal pressure of the case 3 rises to a predetermined pressure. The gas discharge valve 56 of the present embodiment is provided at the center of the lid plate 5 in the X-axis direction.

Specifically, the gas discharge valve 56 is partially torn when the internal pressure (gas pressure) of the case 3 becomes larger than a predetermined value, so that the inside (internal space 30) and the outside (outside) of the case 3 are partially torn. It communicates with the space). As a result, the gas discharge valve 56 discharges the gas inside the case 3 to the outside. In this way, the gas discharge valve 56 lowers the increased internal pressure of the case 3.

The lid plate 5 is provided with a pair of through holes for communicating the inside and the outside of the case 3. The through hole 57 is used to conduct the electrode body 2 housed inside the case 3 and the external terminal 6 arranged outside the case 3. Specifically, the through hole 57 penetrates the lid plate 5 in the Z-axis direction (thickness direction). The through holes 57 are provided at both ends of the lid plate 5 in the X-axis direction. That is, the pair of through holes 57 are provided in the lid plate 5 at intervals in the X-axis direction.

The case 3 is provided with a liquid injection hole 58 for injecting the electrolytic solution. The liquid injection hole 58 communicates between the inside and the outside of the case 3. The liquid injection hole 58 of the present embodiment is provided in the lid plate 5. The liquid injection hole 58 penetrates the lid plate 5 in the Z-axis direction (thickness direction). The liquid injection hole 58 is a circular hole. The liquid injection hole 58 is provided between the gas discharge valve 56 in the X-axis direction and one of the pair of through holes 57.

The liquid injection hole 58 configured as described above is sealed (closed) by the liquid injection plug 59. The liquid injection plug 59 of the present embodiment is fixed to the case 3 (the lid plate 5 in the example of the present embodiment) by welding.

The external terminal 6 is a portion electrically connected to an external terminal of another power storage element, an external device, or the like. Further, the external terminal 6 projects to the outside of the case 3. The external terminal 6 is formed of a conductive member. For example, the external terminal 6 is formed of an aluminum-based metal material such as aluminum or an aluminum alloy, or a metal material such as a copper-based metal material such as copper or a copper alloy.

The external terminal 6 of the present embodiment has a surface 61 to which a bus bar or the like can be welded. The surface 61 of this embodiment is a flat surface. The external terminal 6 has a plate shape that extends along the lid plate 5. Specifically, the external terminal 6 has a rectangular plate shape in the Z-axis direction.

The external terminal 6 of this embodiment projects to the outside of the case 3. Further, the external terminal 6 includes a positive electrode terminal 6A and a negative electrode terminal 6B arranged on the outer surface 50 of the lid plate 5 at intervals from each other.

The index unit 7 is a portion that serves as an index for positioning the power storage element 1. Further, the index unit 7 is a portion that can be recognized from the appearance. Specifically, the index unit 7 is a portion of the outer surface 50 of the lid plate 5 where the position where the index unit 7 is formed can be recognized by appearance.

Further, the index portion 7 is at least one of a concave portion recessed inside the case 3 and a convex portion protruding outward from the case 3. The index unit 7 of the present embodiment is a convex portion protruding outward from the case 3. Further, the index unit 7 is formed by a coining process. That is, the index portion 7 is a portion in which the outer surface 50 (outer surface) side of the lid plate 5 is raised in a convex shape and the inner surface 53 (inner surface) side of the lid plate 5 is recessed in a concave shape.

Further, the index unit 7 has a circular shape when viewed from the Z-axis direction (thickness direction of the lid plate 5). Further, the index unit 7 is smaller than the external terminal 6 when viewed from the Z-axis direction. The index unit 7 is smaller than the gas discharge valve 56 when viewed from the Z-axis direction.

The index portion 7 of the present embodiment is the positive electrode side index portion 7A arranged on the positive electrode terminal 6A side of the outer surface 50 of the lid plate 5 with respect to the central portion of the positive electrode terminal 6A and the negative electrode terminal 6B, and the outer surface 50. Among them, a negative electrode side index portion 7B arranged on the negative electrode terminal 6B side of the central portion of the positive electrode terminal 6A and the negative electrode terminal 6B is included. In the index unit 7 of the present embodiment, the distance between the positive electrode side index unit 7A and the positive electrode terminal 6A is the same as the distance between the negative electrode side index unit 7B and the negative electrode terminal 6B in the X-axis direction. Further, in the X-axis direction, the positive electrode side index portion 7A, the negative electrode side index portion 7B, the positive electrode terminal 6A, and the negative electrode terminal 6B are arranged side by side. Further, the positive electrode side index portion 7A and the negative electrode side index portion 7B are arranged at positions symmetrical with respect to the central portion (for example, the center) of the lid plate 5 in the Z-axis direction view of the lid plate 5. As a result, for example, when arranging the power storage element 1 when assembling the power storage module, when the power storage element 1 is moved by grasping the index unit 7 (for example, the positive electrode side index unit 7A and the negative electrode side index unit 7B), the power storage element 1 is stored. This is preferable because the posture of the element 1 is stable and the positioning accuracy is further improved.

The shape of the positive electrode side index portion 7A is different from the shape of the negative electrode side index portion 7B. The shape of the index unit 7 of the present embodiment is different in that the shape of the groove provided on the outer surface of the index unit 7 is different. Further, information on the positive electrode is displayed on the positive electrode side index unit 7A. Information about the negative electrode is displayed on the negative electrode side index unit 7B. Specifically, the positive electrode side index portion 7A has a disk shape in which a + -shaped groove is provided on the outer surface. Further, the negative electrode side index portion 7B has a disk shape in which a −-shaped groove is provided on the outer surface.

The current collector 8 is arranged in the case 3 and is directly or indirectly connected to the electrode body 2 so as to be energized. Further, the current collector 8 is formed of a conductive member.

In the above power storage element 1, the positive electrode terminals 6A and the negative electrode terminals 6B arranged at intervals in the X-axis direction and the positive electrode terminals 6A and the negative electrode terminals 6B are arranged on the outer surface 50 of the lid plate 5 of the case 3. The index unit 7 is arranged. Specifically, a gas discharge valve 56 and a liquid injection plug 59 are arranged between the positive electrode terminal 6A and the negative electrode terminal 6B in addition to the index unit 7. More specifically, the positive electrode side index portion 7A and the liquid injection plug 59 are arranged between the positive electrode terminal 6A and the gas discharge valve 56, and the negative electrode side index portion 7B is arranged between the negative electrode terminal 6B and the gas discharge valve 56. Is placed.

As shown in FIG. 6, the power storage element 1 is used in the power storage module. The power storage module includes at least two power storage elements 1 and a bus bar member that electrically connects two (different) power storage elements 1 to each other. In the power storage module of the present embodiment, the plurality of power storage elements 1 are arranged in a state where the long wall portions 431 of the case 3 (case body 4) face each other.

According to the above-mentioned power storage element 1, since the index unit 7 is provided on the outer surface 50 of the lid plate 5, when the power storage element 1 is arranged when assembling the power storage module, the power storage element 7 is used as a reference for power storage. Since the element 1 can be positioned, the accuracy of the arrangement position of the power storage element 1 when assembling the power storage module can be improved. Further, for example, since the index portion 7 which is a convex portion protruding to the outside of the case 3 can be grasped by being sandwiched by chuck jigs from both sides, the index portion which is a portion which is an index of the arrangement position of the power storage element 1. 7 can also be used to support the power storage element 1 during transportation and assembly.

Further, in the power storage element 1 of the present embodiment, since the index unit 7 has a circular shape when viewed from the Z-axis direction, the index unit 7 can be easily recognized, and thus it is easy to use for positioning the power storage element 1. Further, when the index unit 7 is instructed by the jig (for example, when the index unit 7 is sandwiched and gripped by the chuck jigs from both sides), it is possible to prevent the stress from being partially concentrated on the index unit 7.

Further, in the power storage element 1 of the present embodiment, the shape of the positive electrode side index portion 7A located on the positive electrode terminal 6A side and the shape of the negative electrode side index portion 7B located on the negative electrode terminal 6B side are different. Due to the difference in shape between the 7A and the negative electrode side index portion 7B, it is easy to distinguish between the positive electrode terminal 6A and the negative electrode terminal 6B of the power storage element 1. That is, it is possible to discriminate between the positive electrode and the negative electrode by using the portion that is the index of positioning, and by forming the portion that is the index of positioning in such a shape, the discrimination between the positive electrode and the negative electrode becomes the index of positioning. It is easy because it is possible from the appearance of the part.

In the power storage element 1 of the present embodiment, the positive electrode side index portion 7A located on the positive electrode terminal 6A side and the negative electrode side index portion 7B located on the negative electrode terminal 6B side display information on the positive electrode and the negative electrode, respectively. Based on the information displayed on the positive electrode side index unit 7A and the negative electrode side index unit 7B (for example, by visually recognizing these information), it is easy to distinguish between the positive electrode terminal 6A and the negative electrode terminal 6B of the power storage element 1. In addition, it is easy to understand the information for distinguishing the positive electrode and the negative electrode.

Further, in the power storage element 1 of the present embodiment, the protrusion 52 of the lid plate 5 protruding inward of the case body 4 is inclined so that the portion located on the protruding side is farther from the opening edge 41 of the case body 4. Since the storage element 1 has the inclined surface 520, the lid plate 5 is attached to the case body along the inclined surface 520 of the protrusion 52 even if the position of the lid plate 5 with respect to the case body 4 is slightly deviated. Easy to insert.

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

For example, as shown in FIG. 7, the index unit 7 may be a recess recessed inside the case 3. In this configuration, for example, since a rod-shaped jig that fits with the index unit 7 can be inserted into the index unit 7, the index unit 7 that serves as an index of the arrangement position of the power storage element 1 is transported or assembled. It can also be used to support the power storage element 1. When a plurality of index portions 7 are provided on the lid plate 5, a part of the plurality of index portions 7 is a recess recessed inside the case 3, and the rest of the plurality of index portions protrudes to the outside of the case 3. It may be a convex portion. That is, the index portion 7 may be both a concave portion and a convex portion. Further, since the lid plate 5 is provided with a concave portion or a convex portion as the index portion 7, the concave portion or the convex portion serves as a mounting place for accessories such as a sensor. In particular, when the lid plate 5 is provided with a recess as the index portion 7, by attaching a temperature sensor to the recess, the temperature at a place closer to the element, which is one of the heat generation sources, than the outer surface 50 of the lid plate 5. Since it is possible to measure the temperature, accurate temperature measurement is possible.

The index unit 7 of the above embodiment has a circular shape when viewed from the Z-axis direction, but may have a shape other than the circular shape. As the shape of the index unit 7, for example, a polygonal shape such as an elliptical shape or a rhombus shape when viewed from the Z-axis direction can be considered.

Further, in the index portion 7 of the above embodiment, the positive electrode side index portion 7A has a disk shape in which a + -shaped groove is formed, and the negative electrode side index portion 7B has a disk shape in which a −-shaped groove is formed. , These shapes are different, but these shapes may be different in another respect, or these shapes may be the same. For example, it is conceivable that these shapes are different in that the positive electrode side index portion 7A has a disk shape and the negative electrode side index portion 7B has a polygonal columnar shape. Further, it is conceivable that these shapes are different in that the positive electrode side index portion 7A is one of the convex portion and the concave portion and the negative electrode side index portion 7B is the other of the convex portion and the concave portion. The shapes of the positive electrode side index portion 7A and the negative electrode side index portion 7B may be the same, but their sizes (for example, the sizes when viewed from the Z-axis direction) may be different.

Further, in the index unit 7 of the above embodiment, the positive electrode side index unit 7A displays information about the positive electrode by its shape (+ shaped groove), and the negative electrode side index unit 7B relates to the negative electrode by its shape (-shaped groove). Although the information was displayed, it suffices to display the information in a configuration that can be recognized by the appearance (for example, visual sense). For example, it is conceivable that the positive electrode side index unit 7A and the negative electrode side index unit 7B display information on the positive electrode and the negative electrode by drawing + and-symbols on the positive electrode side index unit 7A and the negative electrode side index unit 7B. .. Further, by making the shape of the positive electrode side index unit 7A and the negative electrode side index unit 7B as viewed from the Z-axis direction, the dimensions in the Z-axis direction, the color, and the like different, the positive electrode side index unit 7A and the negative electrode side index unit 7B can be changed to the positive electrode. It is also conceivable to display information about the negative electrode and the negative electrode.

The index portion 7 of the above embodiment was formed by coining the lid plate 5, but may be formed by joining another member to the lid plate 5, or a part of the lid plate 5 is removed. It may be formed by doing.

The lid plate 5 of the above embodiment has a protrusion 52, but the lid plate 5 may not have the protrusion 52.

Although the protrusion 52 of the above embodiment is a protrusion, it may be a protrusion other than the protrusion (for example, a protrusion such as a conical trapezoid or a hemispherical shape). Further, although the protrusions 52 of the above embodiment are provided at both ends of the lid plate 5 in the X-axis direction, for example, they may be provided at both ends of the lid plate 5 in the Y-axis direction, or the lid plates may be provided at both ends. It may be provided over the entire outer peripheral portion of 5.

The protrusion 52 of the above embodiment was formed by coining the lid plate 5, but may be formed by joining another member to the lid plate 5.

Further, in the above embodiment, the case where the power storage element is used as a chargeable / dischargeable non-aqueous electrolyte secondary battery (for example, a lithium ion secondary battery) has been described, but the type and size (capacity) of the power storage element are arbitrary. Is. Further, in the above embodiment, the lithium ion secondary battery has been described as an example of the power storage element, but the present invention is not limited to this. For example, the present invention can be applied to various secondary batteries, other primary batteries, and power storage elements of capacitors such as electric double layer capacitors.

1 ... Power storage element, 2 ... Electrode body, 3 ... Case, 4 ... Case body, 5 ... Lid plate, 6 ... External terminal, 6A ... Positive terminal, 6B ... Negative terminal, 7 ... Index part, 7A ... Positive side index part , 7B ... Negative electrode side index part, 8 ... Current collector, 21 ... Winding core, 22 ... Laminated body, 30 ... Internal space, 40 ... Opening, 41 ... Opening edge, 42 ... Closing part, 43 ... Body, 50 ... outer surface, 51 ... joint, 52 ... protrusion, 53 ... inner surface, 55 ... recessed position, 56 ... gas discharge valve, 57 ... through hole, 58 ... liquid injection hole, 59 ... liquid injection plug, 61 ... surface , 102 ... Electrode body, 111 ... Can body, 112 ... Seal plate, 431 ... Long wall part, 432 ... Short wall part, 520 ... Inclined surface, θ ... Angle

Claims (6)

With the electrode body
A case body having an opening, a case including a lid plate covering the opening, and a case for accommodating the electrode body.
An external terminal arranged on the outer surface of the lid plate and electrically connected to the electrode body,
An index unit arranged on the outer surface of the lid plate and arranged at a position different from that of the external terminal is provided.
The index portion is at least one of a concave portion recessed inside the case and a convex portion protruding outward from the case.
A power storage element characterized by this. The index portion has a circular shape when viewed from the thickness direction of the lid plate.
The power storage element according to claim 1. The external terminal projects to the outside of the case and
The index portion is smaller than the external terminal when viewed from the thickness direction of the lid plate.
The power storage element according to claim 1 or 2. The external terminals include positive electrode terminals and negative electrode terminals arranged on the outer surface of the lid plate at intervals from each other.
The index portion is a positive electrode side index portion arranged on the positive electrode terminal side of the outer surface of the lid plate with respect to the central portion of the positive electrode terminal and the negative electrode terminal, and the center of the positive electrode terminal and the negative electrode terminal. Including a negative electrode side index portion arranged on the negative electrode terminal side of the portion,
The shape of the positive electrode side index portion is different from the shape of the negative electrode side index portion.
The power storage element according to any one of claims 1 to 3. The external terminals include positive electrode terminals and negative electrode terminals arranged on the outer surface of the lid plate at intervals from each other.
The index portion is a positive electrode side index portion arranged on the positive electrode terminal side of the outer surface of the lid plate with respect to the central portion of the positive electrode terminal and the negative electrode terminal and displaying information on the positive electrode, and the positive electrode terminal. Includes a negative electrode side index portion which is arranged closer to the negative electrode terminal side than the central portion of the negative electrode terminal and displays information about the negative electrode.
The power storage element according to any one of claims 1 to 3. The lid plate has a joint portion to be joined to the opening edge of the case body, and a protrusion portion protruding inward of the case body from a portion adjacent to the joint portion.
The protrusion has an inclined surface that is inclined so that the portion located on the protruding side is farther from the opening edge of the case body.
The power storage element according to any one of claims 1 to 5.

Images