JP2019029116A - Power storage element - Google Patents

Abstract

To provide a power storage element capable of improving efficiency in manufacturing.SOLUTION: A power storage element comprises a positive electrode terminal 200 and a negative electrode terminal 300, and a container 100 having a lid 120. The lid 120 has: a positive electrode side member 130 on which the positive electrode terminal 200 is arranged; and a negative electrode side member 140 on which the negative electrode terminal 300 is arranged, and that is joined with the positive electrode side member 130.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a power storage device including a positive electrode terminal and a negative electrode terminal, and a container having a lid body on which the positive electrode terminal and the negative electrode terminal are arranged.

  2. Description of the Related Art Conventionally, an energy storage device including a positive electrode terminal and a negative electrode terminal and a container having a lid body on which the positive electrode terminal and the negative electrode terminal are arranged is widely known. For example, Patent Document 1 discloses an electric element (storage element) in which a first terminal portion (positive electrode terminal) and a second terminal portion (negative electrode terminal) are fixed to a lid body (lid body) of a container. Yes.

JP-A-2006-58215

  However, in the conventional power storage element as disclosed in Patent Document 1, it is necessary to dispose two electrode terminals, a positive electrode terminal and a negative electrode terminal, on the lid body. It may not be possible to plan. For example, when the positive electrode terminal and the negative electrode terminal cannot be arranged at the same time on the lid, it is necessary to arrange the positive electrode terminal and the negative electrode terminal in order, which takes time. In addition, if a defect is found in either the positive electrode terminal or the negative electrode terminal after placing the positive electrode terminal and the negative electrode terminal on the lid, only the defective one cannot be replaced. Need to be replaced together. As described above, the conventional power storage device has a problem in that it may not be possible to increase efficiency during manufacturing.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a power storage element that can improve efficiency during manufacturing.

  In order to achieve the above object, a power storage device according to one embodiment of the present invention includes a positive electrode terminal, a negative electrode terminal, and a container having a lid, and the lid includes a positive electrode side member on which the positive electrode terminal is disposed. And the negative electrode terminal is disposed and the negative electrode side member joined to the positive electrode side member.

  According to this, in the electricity storage element, the lid of the container includes the positive electrode side member on which the positive electrode terminal is disposed and the negative electrode side member on which the negative electrode terminal is disposed and joined to the positive electrode side member. That is, the power storage element is configured by joining a separate positive electrode side member and negative electrode side member. Thus, by dividing the portion where the electrode terminal of the lid is arranged into the positive electrode side member and the negative electrode side member, the positive electrode side portion and the negative electrode side portion can be handled separately. Thereby, for example, at the time of manufacturing the electricity storage element, it is possible to work on the part on the positive electrode side and the part on the negative electrode side simultaneously in parallel, or if there is a defect in either the part on the positive electrode side or the part on the negative electrode side. It is possible to improve the efficiency at the time of manufacturing, such as replacing only the defective one.

  Moreover, you may decide that either one of the said positive electrode side member and the said negative electrode side member has a protrusion part which protrudes toward the said other in a junction part with the other.

  According to this, in the electricity storage element, one of the positive electrode side member and the negative electrode side member has a protruding portion that protrudes toward the other side at the joint portion with the other side. Thereby, since the said one protrusion part can bear the function of a gas exhaust valve, it is not necessary to provide a gas exhaust valve separately in a cover body, and efficiency at the time of manufacture can be achieved.

  Moreover, you may decide to arrange | position the said protrusion part in the center position of the surface of the said container in which the said protrusion part is provided.

  According to this, the protrusion part of any one of the positive electrode side member and the negative electrode side member is arrange | positioned in the center position of the surface of a container. Thus, by arrange | positioning the said protrusion part in the said center position, the said protrusion part can be effectively functioned as a gas exhaust valve.

  Moreover, you may decide that the joint strength of the said protrusion part and said other is lower than the joint strength in the other part of the said junction part.

  According to this, the bonding strength between the protruding portion of one of the positive electrode side member and the negative electrode side member and the other is lower than the bonding strength at the other portion. As described above, by reducing the bonding strength at the protrusion, the protrusion can effectively function as a gas discharge valve.

  Furthermore, the positive electrode current collector disposed on the positive electrode side member, the negative electrode current collector disposed on the negative electrode side member, and the positive electrode current collector and the negative electrode current collector are sandwiched from both sides. And at least one of the positive electrode current collector and the negative electrode current collector may be disposed in a state of being inserted from the side into the electrode body.

  According to this, in the electricity storage element, at least one of the positive electrode current collector disposed on the positive electrode side member and the negative electrode current collector disposed on the negative electrode side member is inserted in the electrode body from the side. Is arranged. That is, since the positive electrode side member and the negative electrode side member are configured separately, the positive electrode current collector disposed on the positive electrode side member and the negative electrode current collector disposed on the negative electrode side member are also configured separately. Yes. For this reason, in the case of a configuration in which at least one of the positive electrode current collector and the negative electrode current collector is inserted and joined to the electrode body from the side, the at least one of the positive electrode current collector and the negative electrode current collector is moved to the side of the electrode body. Can be easily inserted from either side. Thereby, the efficiency at the time of manufacture of an electrical storage element can be achieved.

  Note that the present invention can be realized not only as a power storage element but also as a lid of a container provided in the power storage element.

  According to the electricity storage device of the present invention, it is possible to improve the efficiency during production.

It is a perspective view which shows the external appearance of the electrical storage element which concerns on embodiment. It is a perspective view which shows each component with which the electrical storage element which concerns on embodiment is provided. It is a perspective view which shows the structure at the time of assembling the electrical storage element which concerns on embodiment. It is a perspective view which shows the structure of the positive electrode side member edge part which concerns on embodiment, and a negative electrode side member edge part. It is the perspective view and sectional drawing which show the structure of the junction part of the positive electrode side member end part and negative electrode side member end part which concern on embodiment. It is a top view which shows an example of the shape of the junction part of the positive electrode side member which concerns on the modification of embodiment, and a negative electrode side member. It is a top view which shows another example of the shape of the junction part of the positive electrode side member and negative electrode side member which concern on the modification of embodiment.

  Hereinafter, a power storage device according to an embodiment of the present invention and a modification thereof will be described with reference to the drawings. It should be noted that each of the embodiments and modifications thereof described below is a comprehensive or specific example. Numerical values, shapes, materials, constituent elements, arrangement positions and connection forms of constituent elements, and the like shown in the following embodiments and modifications thereof are merely examples, and are not intended to limit the present invention. In addition, among the constituent elements in the following embodiments and modifications thereof, constituent elements that are not described in the independent claims indicating the highest concept are described as arbitrary constituent elements. In each drawing, dimensions and the like are not strictly illustrated.

  In the following description and drawings in the embodiments, the direction in which the pair of electrode terminals included in the power storage element is aligned, the direction in which the pair of current collectors are aligned, and both ends of the electrode body (the pair of active material layer non-forming portions) Are defined as the X-axis direction. Moreover, the opposing direction of the long side surface of the container, the short side direction of the short side surface of the container, or the thickness direction of the container is defined as the Y-axis direction. Further, the direction in which the container body and the lid of the electricity storage element are arranged, the longitudinal direction of the short side surface of the container, the extending direction of the legs of the current collector, or the vertical direction is defined as the Z-axis direction. These X-axis direction, Y-axis direction, and Z-axis direction are directions that intersect (orthogonal in this embodiment). Although the case where the Z-axis direction does not become the vertical direction may be considered depending on the usage mode, the Z-axis direction will be described below as the vertical direction for convenience of explanation. In the following description, for example, the X axis direction plus side indicates the arrow direction side of the X axis, and the X axis direction minus side indicates the opposite side to the X axis direction plus side. The same applies to the Y-axis direction and the Z-axis direction.

(Embodiment)
[1 General Description of Power Storage Element 10]
First, a general description of the power storage element 10 in the present embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a perspective view showing an external appearance of a power storage element 10 according to the present embodiment. FIG. 2 is a perspective view showing each component included in the electricity storage device 10 according to the present exemplary embodiment. Specifically, FIG. 2 is an exploded perspective view showing the components included in the electricity storage device 10 in an exploded manner. FIG. 3 is a perspective view showing a configuration when assembling the energy storage device 10 according to the present embodiment. Specifically, FIG. 3A is a perspective view showing a state before the positive electrode current collector 400 and the negative electrode current collector 500 are inserted into the electrode body 600, and FIG. FIG. 6 is a perspective view showing a state after a positive electrode current collector 400 and a negative electrode current collector 500 are inserted into an electrode body 600 from both sides.

  The storage element 10 is a secondary battery that can charge electricity and discharge electricity, and specifically, is a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery. The power storage element 10 is used, for example, for an automobile power source such as an electric vehicle (EV), a hybrid electric vehicle (HEV), or a plug-in hybrid electric vehicle (PHEV), an electronic device power source, and a power storage power source. In addition, the electrical storage element 10 is not limited to a nonaqueous electrolyte secondary battery, A secondary battery other than a nonaqueous electrolyte secondary battery may be sufficient, and a capacitor may be sufficient as it. Moreover, the electrical storage element 10 may be not a secondary battery but a primary battery that can use stored electricity without being charged by a user. Further, in the present embodiment, a rectangular (rectangular) power storage element 10 is illustrated, but the shape of the power storage element 10 is not limited to a rectangular shape, and may be a cylindrical shape, a long cylindrical shape, or the like. Also good.

  As shown in FIG. 1, the electricity storage device 10 includes a container 100 having a container body 110 and a lid 120, a positive electrode terminal 200, a positive electrode gasket 210, a negative electrode terminal 300, and a negative electrode gasket 310. As shown in FIG. 2, a positive electrode current collector 400, a negative electrode current collector 500, and an electrode body 600 are accommodated inside the container 100.

  Moreover, although electrolyte solution (nonaqueous electrolyte) is enclosed inside the container 100, illustration is abbreviate | omitted. In addition, as long as the said electrolyte solution does not impair the performance of the electrical storage element 10, there is no restriction | limiting in particular in the kind, Various things can be selected. In addition to the above-described constituent elements, spacers disposed on the sides of the positive electrode current collector 400 and the negative electrode current collector 500, a liquid injection part for injecting an electrolytic solution into the container 100, or the electrode body 600 An insulating film or the like that wraps the film may be disposed.

[1.1 Description of Configuration of Container 100]
The container 100 is a rectangular parallelepiped (box-shaped) case composed of a container body 110 having a rectangular cylindrical shape and a bottom, and a lid body 120 that is a plate-like member that closes the opening of the container body 110. Specifically, the lid 120 is a flat and rectangular wall portion extending in the X-axis direction, and is disposed on the positive side of the container body 110 in the Z-axis direction. The container body 110 has a flat and rectangular bottom wall on the negative side in the Z-axis direction, a flat and rectangular long side wall on both sides in the Y-axis direction, and a flat and flat on both sides in the X-axis direction. It has five wall parts of a rectangular short side wall part. In addition, the container 100 can be hermetically sealed by welding the lid body 120 and the container body 110 after the electrode body 600 and the like are accommodated inside the container body 110. In addition, although the material of the cover body 120 and the container main body 110 is not specifically limited, For example, it is preferable that they are weldable metals, such as stainless steel, aluminum, aluminum alloy, iron, and a plated steel plate.

  Here, the lid 120 has a positive electrode side member 130 and a negative electrode side member 140. The positive electrode side member 130 is a member on the positive electrode side of the lid body 120 in which the positive electrode terminal 200 is disposed. Specifically, the positive electrode side member 130 is a plate-like member that is substantially half on the plus side in the X-axis direction of the lid 120, and the positive electrode terminal 200, the positive electrode gasket 210, and the positive electrode current collector 400 are disposed (fixed). ing. The negative electrode side member 140 is a member on the negative electrode side of the lid body 120 in which the negative electrode terminal 300 is disposed. Specifically, the negative electrode side member 140 is a plate-like member that is substantially half of the X axis direction negative side of the lid 120, and the negative electrode terminal 300, the negative electrode gasket 310, and the negative electrode current collector 500 are disposed (fixed). ing.

  Further, the positive electrode side member 130 and the negative electrode side member 140 are joined to form the lid 120. Specifically, a positive electrode side member end portion 131 which is an end portion on the negative side in the X-axis direction of the positive electrode side member 130, and a negative electrode side member end portion 141 which is an end portion on the positive side in the X axis direction of the negative electrode side member 140; Are joined by welding or the like to form a joint 121. That is, the lid body 120 is divided into two members, the positive electrode side member 130 and the negative electrode side member 140, at substantially the center position in the X-axis direction. The positive electrode side member 130 and the negative electrode side member are separated from each other. The opposite ends of 140 are joined together to form a joined part 121. A detailed description of the configuration of the positive electrode side member 130 and the negative electrode side member 140 (the configuration of the positive electrode side member end portion 131, the negative electrode side member end portion 141, and the bonding portion 121) will be described later.

[1.2 Description of Configuration of Electrode Body 600]
The electrode body 600 is a power storage element (power generation element) that includes a positive electrode plate, a negative electrode plate, and a separator and can store electricity. The positive electrode plate is an electrode plate in which a positive electrode active material layer is formed on a positive electrode base material layer that is a long strip-shaped current collector foil made of aluminum, an aluminum alloy, or the like. The negative electrode plate is an electrode plate in which a negative electrode active material layer is formed on a negative electrode base material layer that is a long strip-shaped current collector foil made of copper, a copper alloy, or the like. In addition, as a positive electrode active material and a negative electrode active material used for a positive electrode active material layer and a negative electrode active material layer, if it is an active material which can occlude-release lithium ion, a well-known material can be used suitably. Moreover, the separator can use the microporous sheet | seat which consists of resin, for example, and a nonwoven fabric.

  The electrode body 600 is formed by arranging and winding a separator between a positive electrode plate and a negative electrode plate. Specifically, in the electrode body 600, a positive electrode plate and a negative electrode plate are wound while being shifted from each other in the direction of a winding axis (in this embodiment, a virtual axis parallel to the X-axis direction) via a separator. ing. The positive electrode plate and the negative electrode plate have portions where the active material is not coated (the active material layer is not formed) and the base material layer is exposed (the active material layer non-formed portion) at the end portions in the respective shifted directions. )have.

  That is, the electrode body 600 has a positive electrode focusing portion 610 in which an active material layer non-forming portion of the positive electrode plate is laminated and bundled at one end portion in the winding axis direction (end portion on the X axis direction plus side). Yes. Specifically, an active material layer non-formation part of the positive electrode plate is wound to form an opening 611 that opens toward the positive side in the X-axis direction at the center of the positive electrode focusing part 610. As shown in FIG. 3, the positive electrode current collector 400 is inserted into the opening 611 (specifically, an electrode body side arrangement portion 420 of the positive electrode current collector 400 described later is inserted). The opening 611 is a space formed by dividing the positive electrode converging portion 610 into two in the Y-axis direction. If the positive electrode current collector 400 can be inserted, the opening 611 may be any shape. Also good.

  Similarly, the electrode body 600 has a negative electrode focusing portion 620 in which the active material layer non-forming portion of the negative electrode plate is laminated and bundled at the other end portion in the winding axis direction (end portion on the negative side in the X axis direction). doing. Then, by winding the active material layer non-forming portion of the negative electrode plate, an opening 621 that opens toward the negative side in the X-axis direction is formed in the central portion of the negative electrode focusing portion 620, as shown in FIG. In addition, the negative electrode current collector 500 (the electrode body side arrangement portion 520) is inserted into the opening 621. The details of the opening 621 are the same as those of the opening 611.

  Thus, the electrode body 600 is disposed between the positive electrode current collector 400 and the negative electrode current collector 500 from both sides (X-axis direction both sides). In the present embodiment, an oval shape is illustrated as a cross-sectional shape (cross-sectional shape in the YZ plane) of the electrode body 600, but an elliptical shape, a circular shape, a polygonal shape, or the like may be used. Further, the shape of the electrode body 600 is not limited to the wound type, and may be a laminated type in which flat plate plates are laminated.

[1.3 Description of Configuration of Positive Terminal 200 and Negative Terminal 300]
The positive electrode terminal 200 is an electrode terminal electrically connected to the positive electrode plate of the electrode body 600, and the negative electrode terminal 300 is an electrode terminal electrically connected to the negative electrode plate of the electrode body 600. That is, the positive electrode terminal 200 and the negative electrode terminal 300 lead the electricity stored in the electrode body 600 to the external space of the power storage element 10, and in order to store the electricity in the electrode body 600, It is an electrode terminal made of metal for introducing. As described above, the positive terminal 200 is attached and fixed to the positive member 130 of the lid 120, and the negative terminal 300 is attached and fixed to the negative member 140 of the lid 120.

  Specifically, the positive electrode terminal 200 has a shaft portion (not shown) protruding downward, and the shaft portion includes a through hole of the positive electrode side member 130 and a through hole of the positive electrode current collector 400. And fixed to the positive electrode side member 130 together with the positive electrode current collector 400. The method of fixing the positive electrode terminal 200 to the positive electrode side member 130 together with the positive electrode current collector 400 is not limited to caulking. For example, a configuration in which a bolt portion is formed on the shaft portion and fastened with a nut may be used. It may be fixed by. Similarly, the negative electrode terminal 300 is fixed to the negative electrode side member 140 together with the negative electrode current collector 500.

[1.4 Explanation of Configuration of Positive Electrode Current Collector 400 and Negative Electrode Current Collector 500]
The positive electrode current collector 400 is disposed between the positive electrode side end of the electrode body 600 and the side wall of the container body 110, and is electrically and rigidly connected to the positive electrode terminal 200 and the positive electrode plate of the electrode body 600. It is a member provided with. The negative electrode current collector 500 is disposed between the negative electrode side end of the electrode body 600 and the side wall of the container body 110 and is electrically connected to the negative electrode terminal 300 and the negative electrode plate of the electrode body 600. And a member having rigidity. In addition, although the material of the positive electrode collector 400 is not limited, For example, like the positive electrode base material layer of the electrode body 600, it forms with aluminum or aluminum alloy. The material of the negative electrode current collector 500 is not limited, but is formed of, for example, copper or a copper alloy as in the negative electrode base material layer of the electrode body 600.

  As described above, the positive electrode current collector 400 is disposed on the positive electrode side member 130, and the negative electrode current collector 500 is disposed on the negative electrode side member 140. That is, the positive electrode current collector 400 is attached and fixed to the positive electrode side member 130 of the lid 120 together with the positive electrode terminal 200 and the like, and the negative electrode current collector 500 is fixed to the negative electrode side member of the lid 120 along with the negative electrode terminal 300 and the like. It is attached to 140 and fixed.

  Specifically, the positive electrode current collector 400 includes a terminal side arrangement portion 410, an electrode body side arrangement portion 420, and a tip portion 430. The terminal side arrangement portion 410 is a portion that is arranged in a bent state along the side walls of the positive electrode side member 130 and the container main body 110 and is connected to the positive electrode terminal 200. The electrode body side disposing portion 420 is disposed so as to protrude from the terminal side disposing portion 410 and the tip portion 430 toward the electrode body 600 and is inserted into the opening 611 of the positive electrode converging portion 610 and joined to the positive electrode converging portion 610 ( This is the part to be welded. The tip portion 430 is a portion extending downward from the lower end portion of the electrode body side arrangement portion 420. In addition, the joining method of the electrode body side arrangement | positioning part 420 and the positive electrode focusing part 610 may be what welding, such as laser welding, ultrasonic welding, resistance welding, and mechanical other than welding, for example, caulking etc. It may be a simple joint.

  Similarly, the negative electrode current collector 500 has a terminal side arrangement portion 510, an electrode body side arrangement portion 520, and a tip end portion 530. Note that the configuration of the negative electrode current collector 500 is the same as that of the positive electrode current collector 400, and thus detailed description of each part of the negative electrode current collector 500 is omitted. Thus, the positive electrode current collector 400 and the negative electrode current collector 500 are arranged in a state of being inserted into the electrode body 600 from both sides. With such a configuration, the electrode body 600 is held (supported) in a state of being suspended from the lid body 120 by the positive electrode current collector 400 and the negative electrode current collector 500, and shaking due to vibration or impact is suppressed. The

  The positive electrode gasket 210 is an insulating sealing member disposed between the positive electrode side member 130 of the lid 120, the positive electrode terminal 200, and the positive electrode current collector 400. The positive electrode gasket 210 is made of, for example, a resin such as polycarbonate (PC), polypropylene (PP), polyethylene (PE), or polyphenylene sulfide resin (PPS). Since the negative electrode gasket 310 has the same configuration as the positive electrode gasket 210, detailed description thereof is omitted.

[2 Description of the bonding configuration of the positive electrode side member 130 and the negative electrode side member 140]
[2.1 Explanation of Configuration of Positive Electrode Side Member End 131 and Negative Electrode Side Member End 141]
Next, the configuration of the positive electrode side member end portion 131 of the positive electrode side member 130 and the negative electrode side member end portion 141 of the negative electrode side member 140 will be described. FIG. 4 is a perspective view showing configurations of the positive electrode side member end 131 and the negative electrode side member end 141 according to the present embodiment. 4A is an enlarged perspective view showing the positive electrode side member end 131 and the negative electrode side member end 141 of FIG. 2 in an enlarged manner, and FIG. 4B is an enlarged perspective view of FIG. It is sectional drawing which shows the structure at the time of cut | disconnecting the positive electrode side member edge part 131 and negative electrode side member edge part 141 of (a) of IVb-IVb cross section.

  As shown in FIG. 4, the positive electrode side member end portion 131 of the positive electrode side member 130 includes two positive electrode side member first end portions 132 and a positive electrode disposed between the two positive electrode side member first end portions 132. And a side member second end portion 133. The two positive electrode-side member first end portions 132 are end portions on both sides in the Y-axis direction of the positive electrode-side member end portion 131 and have end edges extending in the Y-axis direction. The two positive electrode-side member first end portions 132 are each formed with a stepped step portion 132a having a concave upper portion (a lower portion protruding) along the edge. Further, the positive electrode side member second end portion 133 is a concave portion having a rectangular shape in a top view in which a central portion in the Y axis direction of the positive electrode side member end portion 131 is recessed toward the plus side in the X axis direction. In the positive electrode side member second end portion 133, similarly to the positive electrode side member first end portion 132, a stepped portion 133 a is formed along the edge of the concave portion.

  The negative electrode side member end portion 141 of the negative electrode side member 140 includes two negative electrode side member first end portions 142 and a negative electrode side member second end portion 143 disposed between the two negative electrode side member first end portions 142. And have. The two first negative electrode side member first end portions 142 are end portions on both sides in the Y axis direction of the negative electrode side member end portion 141 and have end edges extending in the Y axis direction. The two negative electrode-side member first end portions 142 are each formed with a stepped step portion 142a having a protruding upper portion (a recessed lower portion) along the edge. Further, the negative electrode side member second end portion 143 is a protruding portion having a rectangular shape in a top view in which a central portion in the Y axis direction of the negative electrode side member end portion 141 protrudes to the X axis direction plus side. In the negative electrode side member second end portion 143, similarly to the negative electrode side member first end portion 142, a step portion 143a is formed along the edge of the protruding portion.

  The positive electrode side member end 131 and the negative electrode side member end 141 have corresponding shapes. That is, for example, as shown in FIG. 3B, since the positive electrode side member end portion 131 and the negative electrode side member end portion 141 are joined, the positive electrode side member first end portion 132 is the negative electrode side member first end portion. Corresponding to 142, the positive electrode side member second end portion 133 has a shape corresponding to the negative electrode side member second end portion 143. Specifically, the inner peripheral shape of the concave portion of the positive electrode side member second end portion 133 and the outer peripheral shape of the protruding portion of the negative electrode side member second end portion 143 have substantially the same shape. Further, the step shape of the stepped portions 132a and 133a and the step shape of the stepped portions 142a and 143a have a vertically symmetrical shape (vertically inverted shape) (see FIGS. 5B and 5C). ).

[2.2 Description of the configuration of the joint 121]
Next, the configuration of the joint 121 between the positive electrode side member end 131 and the negative electrode side member end 141 will be described in detail. FIGS. 5A and 5B are a perspective view and a cross-sectional view showing a configuration of the joint portion 121 between the positive electrode side member end portion 131 and the negative electrode side member end portion 141 according to the present embodiment. Specifically, FIG. 5A is a perspective view showing a configuration of the joining portion 121 when the positive electrode side member end portion 131 and the negative electrode side member end portion 141 of FIG. 4 are joined. 5B is a cross-sectional view showing the configuration of the joint 121 at the position of the positive electrode side member first end portion 132 and the negative electrode side member first end portion 142 of FIG. FIG. 5C is a cross-sectional view illustrating the configuration of the joint 121 at the positions of the positive electrode side member second end portion 133 and the negative electrode side member second end portion 143 of FIG.

  As shown to (a) of FIG. 5, the positive electrode side member end part 131 and the negative electrode side member end part 141 are arrange | positioned in the state in which level | step-difference parts were overlapped, and the positive electrode side member end part 131 and the negative electrode side member A boundary portion with the end portion 141 is joined, and a joined portion 121 is formed. In the present embodiment, the boundary portion is joined by welding such as laser welding, ultrasonic welding, or resistance welding. That is, as shown in FIG. 5B, the positive electrode side member first end portion 132 and the negative electrode side member first end portion 142 are arranged in a state where the stepped portion 132a and the stepped portion 142a are overlapped. The boundary portion is welded to form the joint 121a. Further, as shown in FIG. 5C, the positive electrode side member second end portion 133 and the negative electrode side member second end portion 143 are arranged in a state where the stepped portion 133a and the stepped portion 143a are overlapped. The boundary portion is welded to form the joint 121b.

  Thus, the positive electrode side member end portion 131 and the negative electrode side member end portion 141 are welded in a state where the stepped portions are overlapped with each other, so that laser light reaches the electrode body 600 in laser welding, for example. And stable welding can be performed.

  Here, in the joining part 121, the joining part 121a has a deeper welding depth than the joining part 121b, that is, the area to be welded is large. For this reason, the joining part 121a has higher joining strength (welding strength) than the joining part 121b. In other words, the bonding portion 121b has a lower bonding strength (welding strength) than the bonding portion 121a. With such a configuration, the joint 121 has a function of a gas discharge valve (safety valve) that releases the pressure inside the container 100 when the pressure inside the container 100 rises. That is, the joint part 121 has a part with low joint strength (joint part 121b), and when the pressure inside the container 100 reaches a predetermined opening pressure, the part with low joint strength breaks and opens. Thus, the pressure inside the container 100 is released.

  In this way, one of the positive electrode side member 130 and the negative electrode side member 140 (in this embodiment, the negative electrode side member 140) is in the joint 121 with the other (in this embodiment, the positive electrode side member 130). And a protruding portion (negative electrode side member second end portion 143) protruding toward the other side. Moreover, the said protrusion part is arrange | positioned in the center position of the surface (upper surface of the cover body 120) of the container 100 in which the said protrusion part is provided. And the joint strength (joint strength of the joint part 121b) of the said protrusion part and the said other is lower than the joint strength in the other part of the joint part 121 (joint strength of the joint part 121a).

  In the above configuration, after the positive electrode current collector 400 and the negative electrode current collector 500 are bonded to the electrode body 600, the positive electrode side member end portion 131 and the negative electrode side member end portion 141 are bonded. Then, after the positive electrode current collector 400 and the negative electrode current collector 500 are joined to the electrode body 600 and the positive electrode side member end 131 and the negative electrode side member end 141 are joined, the positive electrode current collector 400, the negative electrode current collector 500 are joined. The electric body 500, the electrode body 600, and the like are inserted into the container body 110, and the container body 110 and the lid body 120 are joined.

  The timing of joining the positive electrode side member end 131 and the negative electrode side member end 141 is not limited to the above. For example, the positive electrode side member end portion 131 and the negative electrode side member end portion 141 may be bonded before the positive electrode current collector 400 and the negative electrode current collector 500 are bonded to the electrode body 600. Alternatively, the positive electrode side member end portion 131 and the negative electrode side member end portion 141 may be joined simultaneously with the joining of the container body 110 and the lid body 120, or after the joining of the container body 110 and the lid body 120. You may go.

  The positive electrode side member 130 and the negative electrode side member 140 may have opposite shapes. That is, for example, the positive electrode side member second end portion 133 of the positive electrode side member end portion 131 may be a protruding portion, and the negative electrode side member second end portion 143 of the negative electrode side member end portion 141 may be a concave portion. In addition, the stepped portions 132a and 133a and the stepped portions 142a and 143a may have opposite shapes (the recessed portions of the steps are vertically reversed).

  Further, the shape of the stepped portions 132a, 133a, 142a, 143a (thickness in the Z-axis direction) and the like, and the welding depth are not limited to those shown in the figure, and are openings when functioning as a gas discharge valve. What is necessary is just to determine suitably by a pressure etc. The joining of the positive electrode side member end portion 131 and the negative electrode side member end portion 141 is not limited to welding, and may be, for example, mechanical bonding such as adhesion or caulking with an adhesive, but the container 100 From the viewpoint of the internal sealing property and the function of the gas discharge valve in the joint 121, welding is preferable.

[3 Description of effects]
As described above, according to the electric storage element 10 according to the embodiment of the present invention, the lid body 120 of the container 100 includes the positive electrode side member 130 in which the positive electrode terminal 200 is disposed and the positive electrode side member in which the negative electrode terminal 300 is disposed. 130 and a negative electrode side member 140 joined to 130. That is, the electricity storage device 10 is configured by joining the separate positive electrode side member 130 and negative electrode side member 140. Thus, by dividing the portion where the electrode terminal of the lid 120 is disposed into the positive electrode side member 130 and the negative electrode side member 140, the positive electrode side portion and the negative electrode side portion can be handled separately. As a result, for example, at the time of manufacturing the electricity storage element 10, the positive electrode portion and the negative electrode portion can be simultaneously operated in parallel, or there is a defect in either the positive electrode portion or the negative electrode portion. For example, it is possible to improve efficiency during manufacturing, such as replacing only the defective one.

  Moreover, in the electrical storage element 10, any one of the positive electrode side member 130 and the negative electrode side member 140 has a protruding portion (negative electrode side member second end portion 143) protruding toward the other at the joint portion 121 with the other. Have. Thereby, since the said protrusion part can bear the function of a gas exhaust valve, it is not necessary to provide a gas exhaust valve in the cover body 120 separately, and efficiency at the time of manufacture can be achieved.

  In addition, the protruding portion (negative electrode side member second end portion 143) of either the positive electrode side member 130 or the negative electrode side member 140 is disposed at the center position of the surface of the container 100. Thus, by arrange | positioning the said protrusion part in the said center position, the said protrusion part can be effectively functioned as a gas exhaust valve.

  Further, the bonding strength between one projecting portion of the positive electrode side member 130 and the negative electrode side member 140 (negative electrode side member second end portion 143) and the other is lower than the bonding strength in the other portion. As described above, by reducing the bonding strength at the protrusion, the protrusion can effectively function as a gas discharge valve.

  In the electricity storage device 10, both the positive electrode current collector 400 disposed on the positive electrode side member 130 and the negative electrode current collector 500 disposed on the negative electrode side member 140 were inserted into the electrode body 600 from both sides. Arranged in a state. Here, in the conventional power storage element, in order to insert the positive electrode current collector and the negative electrode current collector into the electrode body from both sides in a state where the positive electrode current collector and the negative electrode current collector are fixed to the lid body, the interval between the positive electrode current collector and the negative electrode current collector is set. The electrode body is disposed between the positive electrode current collector and the negative electrode current collector after being spread, and the gap between the positive electrode current collector and the negative electrode current collector needs to be narrowed and inserted into the electrode body from both sides. On the other hand, in the electrical storage element 10, since the positive electrode side member 130 and the negative electrode side member 140 are configured separately, the positive electrode current collector 400 and the negative electrode side member 140 disposed on the positive electrode side member 130 are disposed. The negative electrode current collector 500 thus formed is a separate body. For this reason, in the case of a configuration in which both the positive electrode current collector 400 and the negative electrode current collector 500 are inserted and joined to the electrode body 600 from both sides, the electrode body 600 is brought close to both sides of the electrode body 600. Can be easily inserted from both sides. Thereby, the efficiency at the time of manufacture of the electrical storage element 10 can be achieved.

[Description of Modification of Embodiment 4]
The power storage element 10 according to the embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment. That is, the embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  For example, in the above embodiment, the joint 121 between the positive electrode side member 130 and the negative electrode side member 140 has a protruding portion (negative electrode side member second end portion 143) having a rectangular shape when viewed from above. However, the shape of the joint portion 121 is not limited to this, and various shapes are conceivable. 6A and 6B are plan views showing examples of the shapes of the joint portions 122 and 123 of the positive electrode side member 130 and the negative electrode side member 140 according to a modification of the present embodiment. Specifically, these drawings are plan views when the joint portions 122 and 123 are viewed from above (Z-axis direction plus side).

  As shown in FIG. 6A, the central portion of the negative electrode side member end portion 145 protrudes in a semicircular shape toward the positive electrode side member end portion 135, so that the curved joint portion 122 is formed. Further, as shown in FIG. 6B, the corner portion of the negative electrode side member end portion 146 protrudes at an acute angle toward the corner portion of the positive electrode side member end portion 136, whereby the inclined linear joint portion 123 is formed. Yes. Also by these structures, the junction part 122 or 123 can function as a gas exhaust valve, when a protrusion part opens. As described above, various shapes such as a straight line, a curved line, and both a straight line and a curved line are conceivable for the joint portion between the positive electrode side member 130 and the negative electrode side member 140. Note that, in the joint portion 122 or 123, a portion having low joint strength may be formed as in the above embodiment.

  Further, in the above embodiment, in the joint portion 121 between the positive electrode side member 130 and the negative electrode side member 140, the protruding portion (negative electrode side member second end portion 143) is on the surface of the container 100 (upper surface of the lid 120). It was assumed that it was arranged at the center position. However, the arrangement position of the protrusion is not limited to the center position, and may be a position slightly deviated from the center position, or may be an end of the surface of the container 100.

  Moreover, in the said embodiment, in the junction part 121 of the positive electrode side member 130 and the negative electrode side member 140, the joining strength in a protrusion part (negative electrode side member 2nd edge part 143) is more than the joining strength in another part. Was also low. However, the bonding strength of the protruding portion may be equal to the bonding strength of the other portion, or the bonding strength of the protruding portion may be higher than the bonding strength of the other portion.

  Further, in the above embodiment, the protruding portion (negative electrode side member second end 143) is formed in the joint portion 121 between the positive electrode side member 130 and the negative electrode side member 140. May have a configuration in which the protrusion is not formed.

  In the above embodiment, both the positive electrode current collector 400 and the negative electrode current collector 500 are arranged in a state of being inserted into the electrode body 600 from both sides. However, it is sufficient that at least one of the positive electrode current collector 400 and the negative electrode current collector 500 is disposed in a state of being inserted into the electrode body 600 from the side, and either the positive electrode current collector 400 or the negative electrode current collector 500 is used. May not be inserted into the electrode body 600. Alternatively, both the positive electrode current collector 400 and the negative electrode current collector 500 may not be inserted into the electrode body 600.

  In addition, embodiments constructed by arbitrarily combining the constituent elements included in the above-described embodiment and its modifications are also included in the scope of the present invention.

  In addition, the present invention can be realized not only as the electricity storage element 10 but also as the lid 120 of the container 100 included in the electricity storage element 10.

  The present invention is applicable to power storage elements such as lithium ion secondary batteries.

DESCRIPTION OF SYMBOLS 10 Power storage element 100 Container 120 Cover body 121, 121a, 121b, 122, 123 Joint part 130 Positive electrode side member 140 Negative electrode side member 200 Positive electrode terminal 300 Negative electrode terminal 400 Positive electrode current collector 500 Negative electrode current collector 600 Electrode body

Claims (5)

A positive terminal and a negative terminal;
A container having a lid,
The lid is
A positive electrode side member on which the positive electrode terminal is disposed;
An electricity storage device comprising: a negative electrode side member on which the negative electrode terminal is disposed and joined to the positive electrode side member. The power storage element according to claim 1, wherein one of the positive electrode side member and the negative electrode side member has a protruding portion that protrudes toward the other side at a joint portion with the other side. The electric storage element according to claim 2, wherein the protrusion is disposed at a central position on a surface of the container on which the protrusion is provided. The power storage element according to claim 2, wherein a bonding strength between the protruding portion and the other is lower than a bonding strength at another portion of the bonding portion. further,
A positive electrode current collector disposed on the positive electrode side member;
A negative electrode current collector disposed on the negative electrode side member;
The positive electrode current collector and the negative electrode current collector are provided with an electrode body sandwiched from both sides, and
5. The power storage device according to claim 1, wherein at least one of the positive electrode current collector and the negative electrode current collector is disposed in a state of being inserted from the side into the electrode body.

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