JP6578974B2 - Electricity storage element - Google Patents

Description

  The present invention relates to a power storage device including a conductive member that penetrates a container.

  In the electric storage element, an electrode body is accommodated in a container, and a terminal electrically connected to the electrode body is provided exposed from the container. For example, as shown in Patent Document 1, a shaft portion of a terminal passes through a cover plate that is a part of a container and is electrically connected to an electrode body. And an insulator is interposed between the terminal and the cover plate, and by crimping the shaft portion of the terminal, the insulator is brought into close contact with the terminal and the cover plate to ensure the insulation between them. Yes.

JP 2005-56649 A

  By the way, in an electrical storage element, since the internal pressure change inside a container and the pulling-out force with respect to a terminal generate repeatedly, there exists a possibility that a terminal may loosen with respect to a cover plate by these repetition, and may become structurally unstable. For this reason, it is conceivable to separately provide a strength stabilizing member in the power storage element, but this is not preferable because the number of parts increases.

  For this reason, the subject of this invention is providing the electrical storage element which can improve structural stability, suppressing the increase in a number of parts.

  In order to achieve the above object, a power storage element according to one embodiment of the present invention includes a metal container, a current collector, and a resin member integrated with the container. A caulking portion that fixes the current collector and the container in a state of penetrating the electric body is provided.

  According to this configuration, since the container and the resin member are integrated, the number of parts can be reduced. Moreover, the strength can be increased by integrally molding the container and the resin member.

  Further, since the current collector and the container are fixed by the crimping portion, the current collector can be firmly fixed to the container. As described above, since the container and the resin member are integrally molded to increase the strength, if the current collector is fixed to the container via the caulking portion of the resin member, the current collector and the container Can be more firmly fixed.

  In addition, the resin member may have insulating properties, and the resin member may include an interposition portion disposed between the container and the current collector.

  According to this configuration, since the interposition part of the resin member is arranged between the container and the current collector, compared with a case where an insulating member is separately interposed between the container and the current collector. In addition, the number of parts can be suppressed.

  Further, the container may include a through hole through which the caulking portion passes, and a convex portion that is at least a part of the periphery of the through hole and is formed on one of the inner surface and the outer surface of the container.

  According to this structure, since the convex part is formed in at least one part of the periphery of the through-hole in a container, the deformation | transformation of the container at the time of crimping can be suppressed.

  Furthermore, an electrode terminal penetrating the container and joined to the current collector may be provided, and the resin member may be integrated with the electrode terminal together with the container.

  According to this configuration, since the container and the electrode terminal are integrated with the resin member, the number of parts can be reduced. Furthermore, since the current collector is bonded to the electrode terminal and is also fixed to the container via the crimping portion, the bonding between the current collector and the electrode terminal can be stably maintained over a long period of time.

  Further, the joint portion of the electrode terminal that is joined to the current collector is formed in a convex shape that is convex toward the inside of the container, and the current collector has a thin-walled portion that is thinner than the adjacent portion. It may be formed surrounding the joint.

  Here, due to various problems, the internal pressure of the container may rise rapidly, or an overcurrent may flow through the current collector or electrode terminal. However, if a thin portion is formed on the current collector as in this configuration, when the internal pressure rises or an overcurrent occurs, the thin portion breaks and the electrical connection is interrupted. Even if the thin-walled portion breaks, the convex direction of the joint portion formed in a convex shape is reversed, but hardly affects the container itself.

  ADVANTAGE OF THE INVENTION According to this invention, the structural stability of an electrical storage element can be improved, suppressing the increase in a number of parts.

It is a perspective view which shows typically the external appearance of the electrical storage element which concerns on embodiment. It is a perspective view which shows each component with which the container main body of the container of the electrical storage element which concerns on embodiment is isolate | separated, and an electrical storage element is provided. It is a perspective view which shows schematic structure of the cover plate which concerns on embodiment. It is sectional drawing which shows the fixing structure of the positive electrode terminal which concerns on embodiment, a cover plate, a positive electrode collector, and a positive electrode sealing member. It is a perspective view which shows schematic structure of the positive electrode terminal which concerns on embodiment from upper direction. It is a perspective view which shows schematic structure of the positive electrode terminal which concerns on embodiment from the downward direction. It is explanatory drawing which shows schematic structure of the positive electrode terminal which concerns on embodiment. It is a top view which shows schematic structure of the positive electrode terminal attachment part which concerns on embodiment. It is sectional drawing which shows the state immediately after insert molding of the positive electrode terminal attachment part which concerns on embodiment. 10 is a cross-sectional view illustrating a schematic configuration of a lid plate according to Modification 1. FIG. 10 is a cross-sectional view illustrating a schematic configuration of a positive electrode terminal according to Modification 2. FIG.

  Hereinafter, a power storage device according to an embodiment of the present invention will be described with reference to the drawings. Each of the embodiments described below shows a preferred specific example of the present invention. The numerical values, shapes, materials, constituent elements, arrangement positions and connection forms of the constituent elements, manufacturing steps and their order shown in the following embodiments are merely examples, and are not intended to limit the present invention. In addition, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims indicating the highest concept are described as optional constituent elements.

(Embodiment)
First, the configuration of the power storage element 10 will be described.

  FIG. 1 is a perspective view schematically showing an external appearance of a power storage device 10 according to the embodiment. FIG. 2 is a perspective view showing each component included in the electricity storage device 10 by separating the container body 111 of the container 100 of the electricity storage device 10 according to the embodiment.

  In these drawings, the Z-axis direction is shown as the vertical direction, and the Z-axis direction may be described as the vertical direction below. Moreover, since the case where the Z-axis direction does not become the vertical direction is considered depending on the use mode, the Z-axis direction is not limited to the vertical direction. The same applies to the subsequent drawings.

  The power storage element 10 is a secondary battery that can charge electricity and discharge electricity, and more specifically, is a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery. 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.

  As shown in FIGS. 1 and 2, the electricity storage device 10 includes a container 100, a positive electrode terminal 200 and a negative electrode terminal 201, a positive electrode current collector 120 and a negative electrode current collector 130, a positive electrode sealing member 150 and a negative electrode seal. A member 160 and an electrode body 140 are provided.

  A liquid such as an electrolytic solution (non-aqueous electrolyte) is sealed inside the container 100 of the electricity storage element 10, but the illustration of the liquid is omitted. In addition, as long as it does not impair the performance of the electrical storage element 10, as the electrolyte solution enclosed with the container 100, there is no restriction | limiting in particular and various things can be selected.

  The container 100 includes a container body 111 having a rectangular cylindrical shape and a bottom, and a lid plate 110 that is a plate-like member that closes the opening of the container body 111. In addition, the container 100 can be sealed by welding the lid plate 110 and the container main body 111 after the positive electrode current collector 120, the negative electrode current collector 130, the electrode body 140, and the like are accommodated therein. It is possible. The material of the lid plate 110 and the container body 111 is not particularly limited, but is preferably a weldable metal such as stainless steel, aluminum, aluminum alloy, iron, or plated steel plate.

  The electrode body 140 includes a positive electrode, a negative electrode, and a separator, and is a member that can store electricity. In the positive electrode, a positive electrode active material layer is formed on a positive electrode base material foil which is a long strip-shaped metal foil made of aluminum or an aluminum alloy. The negative electrode is obtained by forming a negative electrode active material layer on a negative electrode substrate foil, which is a long strip-shaped metal foil made of copper, a copper alloy, or the like. The separator is a microporous sheet made of resin.

  Here, the positive electrode active material used for the positive electrode active material layer or the negative electrode active material used for the negative electrode active material layer may be a known material as long as it is a positive electrode active material or a negative electrode active material capable of occluding and releasing lithium ions. Can be used.

  The electrode body 140 is formed by winding a layered arrangement so that a separator is sandwiched between the negative electrode and the positive electrode, and is electrically connected to the positive electrode current collector 120 and the negative electrode current collector 130. Has been. In FIG. 2, the electrode body 140 has an oval cross section, but may be circular or elliptical. Further, the shape of the electrode body 140 is not limited to the wound type, and may be a laminated type in which flat plate plates are laminated.

  The positive electrode terminal 200 is an external terminal that is disposed outside the container 100 and is electrically connected to the positive electrode of the electrode body 140. The positive terminal 200 is made of aluminum or an aluminum alloy. The negative electrode terminal 201 is an external terminal that is disposed outside the container 100 and is electrically connected to the negative electrode of the electrode body 140. The negative terminal 201 is made of copper or a copper alloy. The positive electrode terminal 200 and the negative electrode terminal 201 lead electricity stored in the electrode body 140 to the external space of the power storage element 10, and introduce electricity into the internal space of the power storage element 10 to store electricity in the electrode body 140. This is a conductive electrode terminal. The positive electrode terminal 200 and the negative electrode terminal 201 are attached to the lid plate 110 via the positive electrode sealing member 150 and the negative electrode sealing member 160. Detailed structures of the positive electrode terminal 200 and the negative electrode terminal 201 will be described later.

  The positive electrode current collector 120 and the negative electrode current collector 130 are arranged on the inner side of the container 100, that is, on the inner surface (the surface on the negative side in the Z-axis direction) of the lid plate 110. Specifically, the positive electrode current collector 120 is disposed between the positive electrode of the electrode body 140 and the side wall of the container body 111, and is electrically connected to the positive electrode terminal 200 and the positive electrode of the electrode body 140. It is a member provided with rigidity. The negative electrode current collector 130 is disposed between the negative electrode of the electrode body 140 and the side wall of the container body 111, and has conductivity and rigidity electrically connected to the negative electrode terminal 201 and the negative electrode of the electrode body 140. It is a member.

  The positive electrode current collector 120 is formed of aluminum, an aluminum alloy, or the like, like the positive electrode base material foil of the electrode body 140. In addition, the negative electrode current collector 130 is formed of copper, a copper alloy, or the like, like the negative electrode base foil of the electrode body 140.

  The positive electrode sealing member 150 and the negative electrode sealing member 160 are insulators at least partially disposed between the positive electrode terminal 200 and the negative electrode terminal 201 and the lid plate 110. Specifically, the positive electrode sealing member 150 holds the positive electrode terminal 200 with a part of the positive electrode terminal 200 exposed. Similarly, the negative electrode sealing member 160 holds the negative electrode terminal 201 with a part of the negative electrode terminal 201 exposed. The positive electrode sealing member 150 is integrally formed by, for example, insert molding so as to include the cover plate 110 and the positive electrode terminal 200. Similarly, the negative electrode sealing member 160 is integrally formed by insert molding so as to include the cover plate 110 and the negative electrode terminal 201. That is, the positive electrode sealing member 150, the negative electrode sealing member 160, the lid plate 110, the positive electrode terminal 200, and the negative electrode terminal 201 are insert molded bodies integrated by insert molding. For this reason, the positive electrode sealing member 150 and the negative electrode sealing member 160 are resin members formed from insert-moldable resin. Examples of the resin include polyphenylene sulfide (PPS), polypropylene (PP), polyethylene (PE), polybutylene terephthalate (PBT), and phenol resin. In addition, the resin member is not only one type of resin material, but also a combination of a plurality of resin materials, a combination of a resin material and an elastomer material, and a particulate or fibrous inorganic material in the resin material. You may form from what was added. In addition, the positive electrode sealing member 150 and the negative electrode sealing member 160 are preferably made of an insulating member having lower rigidity than the lid plate 110.

  Next, the lid plate 110 will be described.

  FIG. 3 is a perspective view showing a schematic configuration of the lid plate 110 according to the embodiment.

  As shown in FIG. 3, the cover plate 110 is a plate body having a substantially rectangular shape when viewed from above, and each corner portion thereof is formed in an R shape. In the following description, “plan view” refers to a plan view of the upper surface (outer surface) of the cover plate 110.

  A gas exhaust valve 112, a liquid injection port 113, a positive terminal attaching part 114, and a negative terminal attaching part 115 are formed on the lid plate 110.

  The gas discharge valve 112 is formed in an oblong shape in a plan view at the center of the lid plate 110 and is formed thinner than the other portions. The gas discharge valve 112 has a role of releasing the gas inside the container 100 by being opened when the internal pressure of the container 100 increases.

  The liquid injection port 113 is a through-hole for injecting an electrolytic solution when the power storage element 10 is manufactured. After the lid plate 110 is attached to the container main body 111, the liquid injection port 113 is closed by fitting a liquid injection stopper (not shown) after the electrolytic solution is injected.

  The positive electrode terminal attachment portion 114 is a portion to which the positive electrode terminal 200, the positive electrode sealing member 150, and the positive electrode current collector 120 are attached, and is formed at one end portion of the lid plate 110. The negative electrode terminal attaching portion 115 is a portion to which the negative electrode terminal 201, the negative electrode sealing member 160 and the negative electrode current collector 130 are attached, and is formed at the other end portion of the lid plate 110.

  Next, the fixing structure of the positive electrode terminal 200, the cover plate 110, the positive electrode current collector 120, and the positive electrode sealing member 150 will be described in detail.

  FIG. 4 is a cross-sectional view showing a fixing structure of positive electrode terminal 200, lid plate 110, positive electrode current collector 120, and positive electrode sealing member 150 according to the embodiment. FIG. 4 is a cross-sectional view seen from the ZX plane including the IV-IV line in FIG.

  As shown in FIG. 4, the positive electrode terminal 200 is attached to the cover plate 110 while being accommodated in the positive electrode sealing member 150, and the positive electrode current collector 120 is further attached to the positive electrode terminal 200 and the positive electrode sealing member 150. Thus, these are fixed integrally.

  First, a specific configuration of each member will be described.

  FIG. 5 is a perspective view showing a schematic configuration of the positive electrode terminal 200 according to the embodiment from above. FIG. 6 is a perspective view showing a schematic configuration of the positive electrode terminal 200 according to the embodiment from below. 7A and 7B are explanatory views showing a schematic configuration of the positive electrode terminal 200 according to the embodiment. FIG. 7A is a front view, and FIG. 7B is a side view.

  As shown in FIGS. 5 and 7, the positive terminal 200 includes a terminal main body portion 202 and a flange portion 203 that protrudes outward from the periphery of the terminal main body portion 202.

  The terminal main body 202 is a bottomed cylindrical body having an oval shape in plan view, and has an upper end opened and a second end closed. The upper end portion of the terminal main body 202 is formed in a two-stage shape having a lower outer peripheral side and a higher inner peripheral side. This high portion is referred to as a protruding end portion 207. The protruding end 207 is fitted into a hole of a bus bar (not shown) and welded on the boundary line to connect the bus bar and the positive terminal 200.

  A notch 205 is formed at the lower end of the hollow portion 204 over the entire circumference of the hollow portion 204. The notch 205 is formed at a position corresponding to the flange 203.

  The flange portion 203 is formed in an oval shape in plan view, and protrudes uniformly over the entire circumference of the terminal body portion 202. A bottom portion 206, which is the other end portion of the terminal main body portion 202, is disposed inside the flange portion 203 in plan view. The bottom portion 206 has an oval shape in which the flange portion 203 is reduced in plan view. The bottom portion 206 has a convex shape protruding downward from the flange portion 203. That is, when the positive electrode terminal 200 is integrated with the lid plate 110 and the lid plate 110 is assembled to the container main body 111, the bottom portion 206 is convex toward the inside of the container 100.

  FIG. 8 is a plan view showing a schematic configuration of the positive terminal mounting portion 114 according to the embodiment.

  As shown in FIGS. 4 and 8, the positive electrode terminal mounting portion 114 of the lid plate 110 includes a first hole 118 and a second hole 119. The first hole 118 is located on one end side of the lid plate 110, and the second hole 119 is located on the center side of the lid plate 110.

  The first hole portion 118 includes a first through hole 1181 and a first step portion 1182. The first through hole 1181 is a circular through hole through which the positive electrode sealing member 150 passes.

  The first step portion 1182 is formed in a circular shape concentric with the first through hole 1181 so as to surround the entire circumference of the first through hole 1181, and the first through hole 1181 is formed at the center thereof. . That is, the first step portion 1182 is disposed on the outer peripheral portion of the first through hole 1181. The first step portion 1182 only needs to be formed on at least a part of the periphery of the first through-hole 1181, but it is preferable in terms of strength to be formed on the entire periphery.

  The first step portion 1182 includes a first concave portion 1183 formed on one main surface of the cover plate 110 and a first convex portion 1184 formed on the other main surface of the cover plate 110. Here, one main surface of the cover plate 110 becomes the outer surface of the container 100 when the cover plate 110 is attached to the container main body 111, and the other main surface of the cover plate 110 is the cover plate 110 attached to the container main body 111. When attached, it becomes the inner surface of the container 100. For this reason, the first convex portion 1184 has a convex shape that is convex toward the inside of the container 100. The first concave portion 1183 and the first convex portion 1184 are arranged to face each other. As shown in FIG. 4, the inner diameter H1 of the first concave portion 1183 and the outer diameter H2 of the first convex portion 1184 are substantially equal. In FIG. 8, the first convex portion 1184 overlaps the first concave portion 1183 in plan view. That is, the shape (plan view shape) of the first concave portion 1183 and the first convex portion 1184 when the cover plate 110 is viewed in plan is the same. Further, the term “coincidence” mentioned here includes a case where the first concave portion 1183 and the first convex portion 1184 are slightly different in plan view shape even if they do not completely match. In this case, the dimensional difference between the first concave portion 1183 and the first convex portion 1184 only needs to be within an allowable range when the first step portion 1182 is formed by half punching.

  As shown in FIGS. 4 and 7, the second hole portion 119 includes a second through hole 1191 and a second step portion 1192. The second through hole 1191 is an oval through hole in plan view through which the positive electrode sealing member 150 and the positive electrode terminal 200 penetrate. When viewed from the axial direction of the second through hole 1191, the flange 203 is larger than the second through hole 1191. The flange 203 is preferably larger than the second through hole 1191 over the whole, but may be partially larger. For this reason, the planar view shape of the collar part 203 may be other than the circular shape mentioned above. Examples of the other planar view shape of the flange portion 203 include a polygonal shape, a gear shape, and an oval shape.

  The second step portion 1192 is formed in an oval shape that is equally large over the entire circumference of the second through hole 1191 so as to surround the entire circumference of the second through hole 1191, and the second through hole 1191 is formed at the center thereof. Is formed. That is, the second step portion 1192 is disposed on the outer peripheral portion of the second through hole 1191. The second step portion 1192 may be formed on at least a part of the periphery of the second through hole 1191, but it is preferable in terms of strength to be formed on the entire periphery.

  The second step portion 1192 includes a second concave portion 1193 formed on one main surface of the lid plate 110 and a second convex portion 1194 formed on the other main surface of the lid plate 110. For this reason, the second convex portion 1194 has a convex shape that is convex toward the inside of the container 100. And the 2nd recessed part 1193 and the 2nd convex part 1194 are arrange | positioned facing each other. As shown in FIG. 8, the inner edge shape of the second concave portion 1193 and the outer edge shape of the second convex portion 1194 are substantially the same, and the second convex portion 1194 overlaps the second concave portion 1193 in plan view. Yes. That is, the shape (plan view shape) of the 2nd recessed part 1193 and the 2nd convex part 1194 when the cover board 110 is planarly viewed corresponds. Here, “coincidence” with respect to the planar view shape of the second concave portion 1193 and the second convex portion 1194 also has the same meaning as “coincidence” with respect to the planar shape of the first concave portion 1183 and the first convex portion 1184 described above. It is. That is, the dimensional difference between the second concave portion 1193 and the second convex portion 1194 only needs to be within an allowable range when the second stepped portion 1192 is formed by half blanking.

  Here, a concave portion (first concave portion 1183, second concave portion 1193) is formed on one main surface of the cover plate 110, and a convex portion (first convex portion 1184, second convex portion 1194) is formed on the other main surface. However, the concave portion may be formed on the other main surface, and the convex portion may be formed on the one main surface.

  As shown in FIGS. 2 and 4, the positive electrode current collector 120 integrally includes a current collector main body 121 and an electrode body connecting portion 122.

  The current collector main body 121 is a part to which the positive electrode terminal 200 is connected. Specifically, the current collector main body portion 121 is a plate-like portion that includes an upper step portion 123 and a lower step portion 124 that is disposed one step below the upper step portion 123. A through hole 125 through which the positive electrode sealing member 150 passes is formed in the upper stage portion 123.

  On the lower surface of the lower step portion 124, a concave portion 126 having an oval shape in plan view larger than the bottom portion 206 of the positive electrode terminal 206 is formed. A through hole 127 having an oval shape in plan view smaller than the bottom portion 206 is formed on the bottom surface of the concave portion 126. Further, a thin portion 128 is formed on the bottom surface of the recess 126 so as to surround the through hole 127 over the entire circumference. The thin portion 128 is formed in an oval shape in plan view larger than the bottom portion 206. The thin portion 128 is a notch having a triangular cross-sectional shape formed by, for example, engraving or cutting, and is thinner than a portion adjacent to the thin portion 128. The thin-walled portion 128 breaks when the internal pressure of the container 100 suddenly rises or an overcurrent flows through the positive electrode current collector 120 or the positive electrode terminal 200, thereby cutting off the electrical connection. The thin portion 128 may surround the through-hole 127 continuously over the entire circumference, or may intermittently surround it.

  Here, as described above, the plan view shape of the bottom portion 206 is smaller than the plan view shape of the thin wall portion 128 and larger than the plan view shape of the through hole 127. For this reason, the bottom portion 206 of the positive electrode terminal 200 can be disposed and joined to the upper surface of the current collector main body 121 in a region inside the thin portion 128 and outside the through hole 127. For this joining, for example, through welding such as laser welding is used. That is, the bottom part 206 of the positive electrode terminal 200 is a joint part joined to the positive electrode current collector 120 and is surrounded by the thin part 128. When the thin portion 128 breaks, the convex direction of the bottom portion 206 of the positive electrode terminal 200 is reversed. Specifically, in the normal state, the bottom portion 206 is convex toward the inside of the container 100, but when the thin portion 128 is broken, the bottom portion 206 is convex toward the outside of the container 100.

  The electrode body connecting portion 122 is a long leg that is electrically connected to the positive electrode of the electrode body 140. The electrode body connection part 122 is formed continuously with the upper stage part 123 of the current collector main body part 121, and is fixed to the positive electrode of the electrode body 140.

  As shown in FIG. 4, the positive electrode sealing member 150 is an integral body made of a resin member, and integrally includes a fixing portion 152 and a terminal accommodating portion 153.

  The fixing part 152 fixes the positive electrode current collector 120 in a state of passing through the first through hole 1181 of the cover plate 110. Specifically, the fixing portion 152 is in close contact with the first hole 118 of the lid plate 110 and is in close contact with the current collector main body 121 of the positive electrode current collector 120. Thereby, the fixing portion 152 integrates the lid plate 110 and the positive electrode current collector 120. The fixing portion 152 has a caulking portion 154 that penetrates the through hole 125 of the current collector main body portion 121 and is heat caulked to the current collector main body portion 121. The caulking portion 154 has a shape protruding outward from the outer peripheral edge of the through hole 125 along the lower surface of the upper step portion 123 so as to be larger than the through hole 125 in plan view. Since the caulking portion 154 is formed by thermal caulking, the caulking portion 154 comes into close contact with the periphery of the through hole 125 of the positive electrode current collector 120.

  The terminal accommodating portion 153 holds the positive electrode terminal 200 with the upper end portion and the lower end portion of the positive electrode terminal 200 exposed. Specifically, the terminal accommodating portion 153 is in close contact with the positive electrode terminal 200 in a state of passing through the second through hole 1191 of the lid plate 110 and in close contact with the second hole portion 119 of the lid plate 110. Thereby, the terminal accommodating part 153 integrates the cover plate 110 and the positive electrode terminal 200. The terminal accommodating portion 153 exposes the protruding end portion 207 and the bottom portion 206 of the positive electrode terminal 200 and is in close contact with other portions of the positive electrode terminal 200. Therefore, the flange 203 of the positive electrode terminal 200 is integrated with and covered with the positive electrode sealing member 150. A portion of the positive electrode sealing member 150 that covers the flange portion 203 is referred to as a covering portion 156. As described above, since the positive electrode sealing member 150 is an integral body made of a resin member, the covering portion 156 is also a part of the positive electrode sealing member 150 that is an integral body. The covering portion 156 is in close contact with and covers the top surface, side surface, and bottom surface of the flange portion 203. A part of the covering portion 156 is disposed between the flange portion 203 and the current collector main body portion 121. As a result, the positive electrode terminal 200 is prevented from falling off from the terminal accommodating portion 153.

  The middle portion of the positive electrode sealing member 150 in the Z-axis direction is an interposition portion 157 interposed between the cover plate 110 and the positive electrode current collector 120. By the interposition part 157, insulation between the cover plate 110 and the positive electrode current collector 120 is ensured.

  In the above description, the fixing structure of the positive electrode terminal 200, the cover plate 110, the positive electrode current collector 120, and the positive electrode sealing member 150 on the positive electrode side has been described, but the fixing structure on the negative electrode side is substantially the same as the positive electrode side. Here, in the fixing structure on the negative electrode side, different points from the positive electrode side will be described.

  Specifically, the portion different from the positive electrode side in the fixed structure on the negative electrode side is the negative electrode terminal 201. The negative electrode terminal 201 has a structure that is caulked and bonded to the negative electrode current collector 130. For this reason, the notch 205 and the bottom portion 206 of the positive electrode terminal 200 are not provided in the negative electrode terminal 201.

  Note that a fixing structure equivalent to that on the positive electrode side can also be adopted on the negative electrode side.

  Next, a method for manufacturing power storage element 10 according to the present embodiment will be described.

  First, a method for manufacturing the lid plate 110 will be described.

  A gas exhaust valve 112 and a liquid injection port 113 are formed in advance on a plate body that becomes the lid plate 110. Similarly, a first through hole 1181 on the positive electrode side and a negative electrode side and a second through hole 1191 are formed in advance on the plate body. Thereafter, the plate body is half-punched to form the first step portion 1182 and the second step portion 1192 on the positive electrode side and the negative electrode side, so that the positive electrode terminal attachment portion 114 and the negative electrode terminal attachment portion 115 are formed. And form. Thereby, the cover plate 110 shown in FIG. 3 is formed.

  Next, the lid plate 110, the positive electrode terminal 200, the negative electrode terminal 201, the positive electrode terminal 201, the negative electrode terminal 201, and the positive electrode sealing member 150 and the negative electrode sealing member 160 are insert-molded. The sealing member 150 and the negative electrode sealing member 160 are integrated to form an insert molded body.

  FIG. 9 is a cross-sectional view showing a state immediately after the insert molding of the positive electrode terminal mounting portion 114 according to the embodiment.

  As shown in FIG. 9, immediately after the insert molding, that is, before heat caulking, a portion that becomes the caulking portion 154 is a cylindrical portion 154 a. The cylindrical portion 154a is inserted into the through hole 125 of the positive electrode current collector 120, and then the cylindrical portion 154a is thermally crimped to form the crimped portion 154. Further, the positive electrode terminal 200 and the positive electrode current collector 120 are laser-welded, so that the periphery of the positive electrode terminal mounting portion 114 is in the state shown in FIG.

  On the other hand, also on the negative electrode side, the negative electrode current collector 130 is bonded to the negative electrode sealing member 160 and the negative electrode terminal 201 by thermal caulking and caulking.

  Thereafter, the positive electrode of the electrode body 140 is attached to the positive electrode current collector 120, and the negative electrode of the electrode body 140 is attached to the negative electrode current collector 130.

  Thereafter, from the state shown in FIG. 2, the electrode body 140 is covered with an insulating sheet (not shown), accommodated in the container body 111 of the container 100, the lid plate 110 is welded to the container body 111, and the container 100 is assembled. . Next, after injecting an electrolytic solution from the injection port 113, the injection plug 113 is welded to the lid plate 110 to close the injection port 113, whereby the power storage device 10 shown in FIG. 1 is manufactured.

  As described above, according to the present embodiment, the lid plate 110 of the container 100 and the positive electrode sealing member 150 are integrated, so that the number of parts can be reduced. In addition, since the lid plate 110 and the positive electrode sealing member 150 are integrally formed, the strength can be increased.

  Since the positive electrode current collector 120 and the lid plate 110 are fixed by the crimping portion 154, the positive electrode current collector 120 can be firmly fixed to the lid plate 110. Further, since the lid plate 110 and the positive electrode sealing member 150 are integrated and the strength is increased, the positive electrode current collector 120 is attached to the lid plate 110 via the caulking portion 154 of the positive electrode sealing member 150. If fixed, the positive electrode current collector 120 and the lid plate 110 can be more firmly fixed.

  Furthermore, since the caulking portion 154 is formed by thermal caulking, adhesion between the caulking portion 154 and the positive electrode current collector 120 can be improved. Note that the caulking portion 154 can be formed by caulking other than thermal caulking. Specifically, the caulking portion 154 is a portion formed by plastically deforming a resin and may be deformed by heat or may be plastically deformed by deformation other than heat. .

  Therefore, the structural stability of the electricity storage element 10 can be enhanced while suppressing an increase in the number of parts.

  In addition, since the interposition part 157 of the positive electrode sealing member 150 is disposed between the lid plate 110 and the positive electrode current collector 120, an insulating material is separately provided between the lid plate 110 and the positive electrode current collector 120. Compared with the case where a member is interposed, the number of parts can be suppressed.

  Moreover, since the 1st convex part 1184 is formed in at least one part of the periphery in the 1st through-hole 1181 of the cover plate 110, a deformation | transformation of the cover plate 110 can be suppressed.

  Moreover, since the 2nd convex part 1194 is formed in at least one part of the periphery in the 2nd through-hole 1191 of the cover plate 110, a deformation | transformation of the cover plate 110 can be suppressed.

  Further, since the lid plate 110 and the positive electrode terminal 200 of the container 100 are integrated with the positive electrode sealing member 150, the number of components can be reduced. Furthermore, since the cover plate 110, the positive electrode terminal 200, and the positive electrode sealing member 150 are integrated, the strength can be increased. Since the positive electrode current collector 120 is bonded to the positive electrode terminal 200 and is also fixed to the lid plate 110 via the caulking portion 154, the bonding between the positive electrode current collector 120 and the positive electrode terminal 200 is stable over a long period of time. Can be maintained.

  In addition, due to various problems, the internal pressure of the container 100 may rise rapidly, or an overcurrent may flow through the positive electrode current collector 120 or the positive electrode terminal 200. However, since the thin-walled portion 128 is formed on the positive electrode current collector 120, when the internal pressure rises or an overcurrent occurs, the thin-walled portion 128 breaks and the electrical connection is interrupted. When the thin portion 128 is broken, the convex direction of the bottom portion 206 formed in a convex shape is reversed. Although a physical load is generated by this inversion, since the positive electrode sealing member 150 is interposed between the lid plate 110 and the positive electrode terminal 200, the load hardly affects the lid plate 110 itself.

  Further, since the flange portion 203 of the positive electrode terminal 200 protrudes toward the positive electrode sealing member 150 and is integrated with the positive electrode sealing member 150, the positive electrode terminal 200 is exposed to an external load or a high pressure inside the container 100. Even if a force that pulls outward is applied to the terminal 200, the flange 203 can be caught by the positive electrode sealing member 150 and the positive electrode terminal 200 can be prevented from coming off.

  In addition, since the flange 203 is larger than the second through hole 1191 of the cover plate 110, even if an external force is applied to pull out the positive electrode terminal 200, the cover plate 110 is locally applied to the portion forming the second through hole 1191. However, stress is applied to the entirety including the flange portion 203. For this reason, deformation of the lid plate 110 can be suppressed. In other words, it will be able to withstand greater external forces.

  Moreover, since the coating | coated part 156 has coat | covered the bottom face of the collar part 203, it can suppress that the positive electrode terminal 200 falls from the positive electrode sealing member 150 in an axial direction.

  Moreover, since the coating | coated part 156 is arrange | positioned between the collar part 203 and the positive electrode collector 120, it can suppress that the collar part 203 and the positive electrode collector 120 contact. When the positive electrode sealing member 150 has an insulating property as in the present embodiment, the flange portion 203 and the positive electrode current collector 120 can be reliably insulated.

(Modification 1)
Next, Modification 1 according to the above embodiment will be described. In the above embodiment, the case where the first stepped portion 1182 and the second stepped portion 1192 are provided on the cover plate 110 has been described as an example. However, the first stepped portion and the second stepped portion may not be formed on the lid plate.

  FIG. 10 is a cross-sectional view illustrating a schematic configuration of a lid plate 110A according to the first modification, and corresponds to FIG. In the following description, parts that are the same as those in the above embodiment may be given the same reference numerals and description thereof may be omitted.

  As shown in FIG. 10, the cover plate 110 </ b> A according to the first modification is a flat plate, and the first step portion 1181 and the second through hole 1191 are formed at predetermined positions. And the 2nd level | step-difference part is not formed. For this reason, it is possible to shorten the manufacturing process of the cover plate 110A. In addition, from various viewpoints such as strength and manufacturing efficiency, at least one of the first step portion and the second step portion may be formed on the cover plate as necessary.

(Modification 2)
Next, Modification 2 according to the above embodiment will be described. In the above embodiment, the case where the terminal main body portion 202 of the positive electrode terminal 200 is a bottomed cylindrical body and the protruding end portion 207 is fitted into the hole portion of the bus bar has been described as an example. However, the hollow portion of the positive terminal may be closed, and the bus bar may be joined to the closed portion.

  FIG. 11 is a cross-sectional view illustrating a schematic configuration of a positive electrode terminal 200B according to the second modification.

  As shown in FIG. 11, in the positive electrode terminal 200B according to the second modification, the upper portion of the hollow portion 204b of the terminal main body portion 202b is closed by a closing portion 207b. The closing part 207b is integrally formed with the terminal main body part 202b and the flange part 203b, for example, by drawing or casting. Immediately after the integral molding, the bottom portion 206b is separated from the terminal main body portion 202b. The bottom portion 206b is attached to the terminal main body portion 202b so as to close the lower portion of the hollow portion 204b by a process after the integral molding. Specifically, the bottom portion 206b is attached to the terminal main body portion 202b by welding or the like. Thereby, the terminal main body 202b, the flange 203b, the closing part 207b, and the bottom 206b are integrated. After the storage element is assembled, the bus bar is joined to the closing portion 207b of the positive electrode terminal 200B.

(Other embodiments)
As described above, the power storage device according to the embodiment of the present invention and the modified example thereof has been described, but the present invention is not limited to the above-described embodiment and the modified example thereof. That is, it should be considered that the embodiment and its modification disclosed this time are illustrative and not restrictive in all respects. 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 power storage element 10 is provided with one electrode body 140, but may be configured with a plurality of electrode bodies.

  Moreover, in the said embodiment, the case where the 1st level | step-difference part 1182 and the 2nd level | step-difference part 1192 were formed by the half-punching process was illustrated and demonstrated. However, the processing method of the first stepped portion 1182 and the second stepped portion 1192 is not limited to this. For example, other press work such as drawing may be used. Further, the cover plate 110 having the first stepped portion 1182 and the second stepped portion 1192 may be formed by other methods such as casting and cutting, instead of pressing.

  In the above embodiment, the thin-walled portion 128 is formed in the positive electrode current collector 120 in order to cut off the electrical connection when an internal pressure increase or an overcurrent occurs. However, in the case where electrical interruption is not necessary, the thin portion 128 may not be provided. In this case, the positive electrode current collector 120 can be integrated by caulking the positive electrode terminal 200.

  Moreover, in the said embodiment, although the positive electrode side was illustrated and the specific structure of the part used as the characteristic of this invention was demonstrated, of course, the same structure is applied also in the negative electrode side. In addition, as long as it does not deviate from the meaning of this invention, the structure from which the positive electrode side and a negative electrode side differ may be sufficient.

  Moreover, the form constructed | assembled combining the said embodiment and the said modification arbitrarily is also contained in the scope of the present invention.

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

DESCRIPTION OF SYMBOLS 10 Storage element 100 Container 110,110A Cover plate 111 Container main body 112 Gas discharge valve 113 Injection port 114 Positive electrode terminal attachment part 115 Negative electrode terminal attachment part 118 First hole part 119 Second hole part 120 Positive electrode collector (current collector) )
121 current collector main body 122 electrode body connecting part 123 upper stage part 124 lower stage part 125, 127 through hole 126 concave part 128 thin part 130 negative electrode current collector 140 electrode body 150 positive electrode sealing member (resin member)
152 Fixing part 153 Terminal accommodating part 154 Caulking part 154a Cylindrical part 156 Covering part 157 Interposition part 160 Negative electrode sealing member 200, 200B Positive electrode terminal (electrode terminal)
201 Negative electrode terminals 202 and 202b Terminal body portions 203 and 203b Fence portions 204 and 204b Hollow portions 205 Notches 206 and 206b Bottom portions (joining portions)
207 Protruding end portion 207b Closure portion 1181 First through hole (through hole)
1182 First Step 1183 First Concave 1184 First Convex (Convex)
1191 2nd through-hole 1192 2nd level difference part 1193 2nd recessed part 1194 2nd convex part H1 Inner diameter H2 of 1st recessed part Outer diameter of 1st convex part

Claims (5)

A metal container;
A current collector,
A resin member integrated with the container,
The resin member includes a caulking portion that fixes the current collector and the container in a state of penetrating the container and the current collector. The resin member has an insulating property,
The electricity storage device according to claim 1, wherein the resin member includes an interposition portion disposed between the container and the current collector. The container is
A through hole through which the caulking portion passes,
The power storage device according to claim 1, further comprising: a convex portion that is at least a part of a peripheral edge of the through hole and is formed on one of an inner surface and an outer surface of the container. further,
An electrode terminal penetrating the container and joined to the current collector;
The electric storage element according to claim 1, wherein the resin member is integrated with the electrode terminal together with the container. The joint portion to be joined to the current collector in the electrode terminal is formed in a convex shape that is convex toward the inside of the container,
The power storage element according to claim 4, wherein the current collector is formed with a thin portion thinner than an adjacent portion so as to surround the joint portion.

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