JP2018098130A - Power storage element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress an assembling failure caused by a protrusion of a sealing member. An energy storage device 10 includes a sealing member (a positive electrode first sealing member 150) disposed between a terminal (a positive electrode terminal 200) or a current collector (a positive electrode current collector 120) and a container 100. .. The sealing member includes a first surface 1531 facing the container and a second surface 1512 facing the terminal or the current collector. A first protrusion 154 is formed on the first surface so as to surround the shaft portion 220 of the terminal. A second protrusion 155 is formed on the second surface to surround the shaft of the terminal. The first protrusion and the second protrusion are arranged in a state where the sealing member is compressed between the terminal or the current collector and the container. The power storage element is formed on the first facing surface 1101 that faces the first surface of the container, and faces the first recess 114 that accommodates the first protrusion in a compressed state and the second surface of the terminal or the current collector. At least one of the second concave portion 212 which is formed on the second facing surface 2102 and accommodates the second protrusion in a compressed state is provided. [Selection diagram] Fig. 4

Description

  The present invention relates to a power storage element.

  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. A sealing member is interposed between the container and the terminal, and the sealing member ensures airtightness around the terminal and improves the quality of the power storage element itself (for example, see Patent Document 1).

JP 2011-165543 A

  In recent years, a method for improving airtightness by providing a protrusion on a sealing member and compressing the protrusion with a container and a terminal has been studied. However, it is assumed that the protrusions cannot be completely compressed. In such a case, the parallelism of the terminals is impaired, and there is a possibility that poor assembly is caused.

  For this reason, the subject of this invention is providing the electrical storage element which can suppress the assembly | attachment failure resulting from the protrusion of a sealing member.

  In order to achieve the above object, a power storage element according to one embodiment of the present invention is a power storage element including a terminal provided in a container and a current collector electrically connected to the terminal. A sealing member disposed between the electric body and the container, wherein the sealing member has a first surface facing the container and a second surface facing the terminal or the current collector on the side opposite to the first surface; A first protrusion that surrounds the terminal shaft portion is formed on the first surface, and a second protrusion that surrounds the shaft portion of the terminal is formed on the second surface. The one projecting portion and the second projecting portion are compressed when the sealing member is compressed between the terminal or the current collector and the container, and the power storage element is the first facing the first surface of the container. Formed on one opposing surface, formed on a first concave portion that accommodates the first protrusion in a compressed state, and a second opposing surface that opposes the second surface of the terminal or current collector, Comprising at least one of the second recess to accommodate compressed state two projections.

  According to this configuration, since at least one of the first concave portion that accommodates the first protrusion in a compressed state and the second concave portion that accommodates the second protrusion in a compressed state is provided in the storage element, The first protrusion or the second protrusion that protrudes to some extent after compression can be accommodated in the first recess or the second recess. Thereby, the parallelism between the container and the terminal or the current collector can be ensured. Therefore, it is possible to suppress an assembly failure caused by the first protrusion or the second protrusion.

  The power storage element may include a first recess and a second recess.

  According to this configuration, since both the first concave portion and the second concave portion are provided in the power storage element, even if the first protrusion and the second protrusion remain protruding to some extent after compression, The protrusion can be accommodated by the recess and the second recess. Therefore, it is possible to further suppress the assembly failure caused by the first protrusion and the second protrusion.

  Further, the first protrusion and the second protrusion may overlap with each other when the shaft portion is viewed in the axial direction.

  According to this configuration, since the first protrusion and the second protrusion are arranged at a position where they overlap in a plan view, the force acting on the first protrusion and the second protrusion during compression can be seen in a plan view. It can be given evenly. Therefore, stability after compression can be improved.

  According to the present invention, it is possible to suppress an assembly failure caused by the protruding portion of the sealing member.

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 sectional drawing which shows schematic structure of the fixing structure which concerns on embodiment. It is sectional drawing which shows the state before fixation of the fixing structure which concerns on embodiment. It is a top view which shows the shape by the side of the positive electrode of the cover which concerns on embodiment. It is a bottom view which shows schematic structure of the positive electrode terminal which concerns on embodiment. It is a bottom view of the positive electrode 1st sealing member which concerns on embodiment. 10 is a cross-sectional view illustrating a fixing structure of a power storage device according to Modification 1. FIG. 10 is a cross-sectional view showing a fixing structure of a power storage device according to Modification 2. FIG. 10 is a cross-sectional view illustrating a schematic configuration of a fixing structure according to Modification 3. FIG. It is sectional drawing which shows the state before fixation of the fixing structure which concerns on the modification 3.

  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. Numerical values, shapes, materials, constituent elements, arrangement positions and connection forms of constituent elements, and the like 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.

  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 element 10 according to the present embodiment. FIG. 2 is a perspective view showing each component included in power storage element 10 by separating container body 111 of container 100 of power storage element 10 according to the present embodiment.

  In these drawings, the Z-axis direction is shown as the up-down direction, and in the following description, the Z-axis direction may be described as the up-down direction. For this reason, 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. Further, the power storage element 10 may be a primary battery.

  As shown in FIGS. 1 and 2, the storage element 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 first sealing member 150, and a negative electrode. A first sealing 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 body 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 body 110 and the container 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 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 base foil that is a long strip-shaped metal foil made of copper, copper alloy, aluminum, aluminum 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.

Examples of the positive electrode active material include polyanion compounds such as LiMPO ₄ , LiMSiO ₄ , LiMBO ₃ (M is one or more transition metal elements selected from Fe, Ni, Mn, Co, etc.), titanium, and the like. Use of spinel compounds such as lithium oxide and lithium manganate, lithium transition metal oxides such as LiMO ₂ (M is one or more transition metal elements selected from Fe, Ni, Mn, Co, etc.), etc. Can do.

Examples of the negative electrode active material include lithium metal, lithium alloy (lithium metal such as lithium-aluminum, lithium-silicon, lithium-lead, lithium-tin, lithium-aluminum-tin, lithium-gallium, and wood alloy). Alloys), alloys capable of inserting and extracting lithium, carbon materials (eg, graphite, non-graphitizable carbon, graphitizable carbon, low-temperature calcined carbon, amorphous carbon, etc.), metal oxides, lithium metal oxides ( Li ₄ Ti ₅ O ₁₂ etc.), polyphosphoric acid compounds and the like.

  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 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. In other words, the positive electrode terminal 200 and the negative electrode terminal 201 lead the electricity stored in the electrode body 140 to the external space of the power storage element 10, and in order to store the electricity in the electrode body 140, It is a conductive electrode terminal for introducing. The positive electrode terminal 200 and the negative electrode terminal 201 are attached to the lid 110 via the positive electrode first sealing member 150 and the negative electrode first sealing member 160.

  The positive electrode current collector 120 and the negative electrode current collector 130 are disposed 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 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 first sealing member 150 and the negative electrode first sealing member 160 are gaskets in which at least a part thereof is disposed between the positive electrode terminal 200 and the negative electrode terminal 201 and the lid 110. Specifically, the positive electrode first sealing member 150 has a recess 151 whose upper side is open, and the positive electrode terminal 200 is accommodated in the recess 151. Similarly, the negative electrode first sealing member 160 has a recess 161 whose upper side is open, and the negative electrode terminal 201 is accommodated in the recess 161. Thereby, the positive electrode terminal 200 and the negative electrode terminal 201 are attached to the lid body 110 with a part thereof exposed.

  Next, a fixing structure in which the positive electrode terminal 200 is fixed to the lid 110 together with the positive electrode current collector 120 via the positive electrode first sealing member 150 will be described. This fixing structure is substantially the same as the fixing structure in which the negative electrode terminal 201 is fixed to the lid 110 together with the negative electrode current collector 130 via the negative electrode first sealing member 160, and therefore the description on the negative electrode side is omitted. .

  FIG. 3 is a cross-sectional view showing a schematic configuration of the fixing structure according to the present embodiment. 3 is a cross-sectional view of the YZ plane including the line III-III in FIG. FIG. 4 is a cross-sectional view showing a state before fixing of the fixing structure according to the present embodiment, and corresponds to FIG.

  As shown in FIGS. 3 and 4, the positive electrode terminal 200 is attached to the lid 110 in a state of being accommodated in the positive electrode first sealing member 150, and the positive electrode second sealing is further attached to the positive electrode first sealing member 150. The positive electrode current collector 120 is attached via the member 170 so that they are integrally fixed.

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

  FIG. 5 is a plan view showing the shape of the positive electrode side of lid 110 according to the present embodiment.

  As shown in FIGS. 3 to 5, the lid body 110 is formed with a through hole 112 into which a part of the positive electrode first sealing member 150 in a state where the positive electrode terminal 200 is accommodated is inserted. The upper surface of the lid 110 is a first facing surface 1101 that faces a first surface 1531 of a positive electrode first sealing member 150 described later. A first recess 114 surrounding the through hole 112 is formed on the first facing surface 1101. Specifically, the first recess 114 is formed in an annular shape in plan view (see FIG. 5). Moreover, the 1st recessed part 114 is formed in the cross sectional view rectangular shape (refer FIG.4 and FIG.5). In addition, the “plan view” referred to in the present embodiment refers to an axial view of a shaft portion 220 of the positive electrode terminal 200 described later, specifically, a Z-axis direction view.

  On the other hand, a positioning projection 113 for positioning the positive electrode second sealing member 170 is provided on the lower surface of the lid 110 in a shape corresponding to the outer shape of the positive electrode second sealing member 170.

  The positive electrode second sealing member 170 is a gasket in which at least a part thereof is disposed between the positive electrode current collector 120 and the lid body 110. The positive electrode second sealing member 170 is preferably lower in rigidity than the lid body 110 and formed of an insulating member. The positive electrode second sealing member 170 includes, for example, polyphenylene sulfide (PPS), polypropylene (PP), polyethylene (PE), polybutylene terephthalate (PBT), polytetrafluoroethylene (PFA), polyether ether ketone (PEEK), and the like. Made of resin.

  The bottom surface of the positive electrode second sealing member 170 is formed with a recess 171 in which the current collector main body 121 of the positive electrode current collector 120 is accommodated. A through hole 172 having the same shape as the through hole 112 of the lid 110 is formed in the recess 171. The through hole 172 is arranged so as to be continuous with the through hole 112 of the lid 110, and the cylindrical portion 152 of the positive electrode first sealing member 150 is inserted into the through holes 172 and 112.

  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 121 is formed in a flat plate shape and has a through hole 123 into which the shaft portion 220 of the positive electrode terminal 200 is inserted.

  The electrode body connecting portion 122 is two elongated legs that are electrically connected to the positive electrode of the electrode body 140. The electrode body connection part 122 is arranged outward (X-axis direction minus side) from the through hole 123 of the current collector main body part 121. The electrode body connection part 122 is fixed to the positive electrode in a state where the positive electrode of the electrode body 140 is sandwiched in the Y-axis direction (see FIG. 2).

  Next, the positive electrode terminal 200 will be described.

  FIG. 6 is a bottom view showing a schematic configuration of the positive electrode terminal 200 according to the present embodiment. FIG. 6 shows a state before the shaft portion 220 of the positive electrode terminal 200 is caulked.

  As shown in FIGS. 3, 4, and 6, the positive electrode terminal 200 includes a bus bar connection part 210 and a shaft part 220 integrally.

  The bus bar connection part 210 is a part to which a bus bar (not shown) that connects the electrode terminals of the electricity storage element 10 is connected, and the upper surface is formed in a plane. A shaft portion 220 is provided on the lower surface of the bus bar connection portion 210. The lower surface of the bus bar connecting portion 210 is a second facing surface 2102 that faces a second surface 1512 of the positive electrode first sealing member 150 described later. A second concave portion 212 surrounding the shaft portion 220 is formed on the second facing surface 2102. Specifically, the second recess 212 is formed in an annular shape in plan view (see FIG. 6). Moreover, the 2nd recessed part 212 is formed in the cross sectional view rectangular shape (refer FIG.3 and FIG.4).

  The shaft portion 220 is a portion extending downward from the lower surface of the bus bar connection portion 210. As shown in FIG. 3, the shaft portion 220 has the tip portion 230 caulked so that the positive electrode first sealing member 150, the positive electrode second sealing member 170, the positive electrode current collector 120, and the lid body 110. Is fixed. When viewed from the Z-axis direction, the tip portion 230 of the shaft portion 220 is annular and is in close contact with the surface of the current collector main body 121. The distal end portion 230 and the bus bar connecting portion 210 connect the current collector body 121 of the positive electrode current collector 120, the positive electrode first sealing member 150, the positive electrode second sealing member 170, and the lid body 110. Tightened in the Z-axis direction. As shown in FIG. 4, the shaft portion 220 before caulking has a tip portion before deformation, and the shaft portion 220 as a whole has a cylindrical shape.

  Next, the positive electrode first sealing member 150 will be described.

  FIG. 7 is a bottom view of the positive electrode first sealing member 150 according to the present embodiment.

  As shown in FIGS. 3, 4, and 7, the positive electrode first sealing member 150 integrally includes a terminal accommodating portion 153 and a cylindrical portion 152.

  On the upper surface of the terminal accommodating portion 153, a recess 151 for accommodating the bus bar connecting portion 210 of the positive electrode terminal 200 is formed. The lower surface of the terminal accommodating portion 153 is a first surface 1531 that faces the lid 110 of the container 100.

  A first protrusion 154 surrounding the cylindrical portion 152 is formed on the first surface 1531. Specifically, the first protrusion 154 is a semi-elliptical protrusion in cross-sectional view. The first protrusion 154 is formed in an annular shape centering on the axial center of the cylindrical portion 152 at a position where it is accommodated in the first recess 114 of the lid 110. The protrusion amount H1 of the first protrusion 154 is set to be greater than the depth D1 of the first recess 114. As a result, when the tip end portion 230 of the positive electrode terminal 200 is caulked, the first protrusion 154 is compressed in the first recess 114 by the difference between the protrusion amount H1 and the depth D1. The compressed first protrusion 154 ensures airtightness between the positive electrode terminal 200 and the positive electrode first sealing member 150.

  The bottom surface of the recess 151 of the terminal accommodating portion 153 is a second surface 1512 facing the positive electrode terminal 200 on the side opposite to the first surface 1531. A second protrusion 155 surrounding the cylindrical portion 152 is formed on the second surface 1512. Specifically, the second protrusion 155 is a protrusion having a semi-elliptical shape in cross section. The second protrusion 155 is formed in an annular shape around the axis of the cylindrical portion 152 at a position where it is accommodated in the second recess 212 of the positive electrode terminal 200. The second protrusion 155 and the second recess 212 are formed at positions that overlap the first protrusion 154 and the first recess 114 in plan view, respectively. It is preferable that the second protrusion 155 and the first protrusion 154 overlap as a whole in plan view.

  The protrusion amount H2 of the second protrusion 155 is set to be greater than the depth D2 of the second recess 212. The protrusion amount H2 of the second protrusion 155 may be the same as the protrusion amount H1 of the first protrusion 154.

  And if the front-end | tip part 230 of the positive electrode terminal 200 is crimped, the 2nd protrusion 155 will be in the state compressed in the 2nd recessed part 212 by the difference of protrusion amount H2 and depth D2. The compressed second protrusion 155 ensures airtightness between the lid 110 and the positive electrode first sealing member 150.

  Here, even if the first protrusion 154 or the second protrusion 155 is compressed by a flat surface, the first protrusion 154 or the second protrusion 155 is not completely compressed, and the first surface 1531 or the second surface 1512 is not compressed. In some cases, the shape protruding above remains. The remaining first protrusion 154 or second protrusion 155 impairs the parallelism between the positive electrode terminal 200 and the lid 110. However, in the present embodiment, the first protrusion 154 is compressed while being accommodated in the first recess 114 of the positive electrode terminal 200, and the second protrusion 155 is accommodated in the second recess 212 of the positive electrode terminal 200. It is compressed in the state. For this reason, even if a protrusion remains after compression, it is accommodated by the first recess 114 or the second recess 212, and the parallelism between the positive electrode terminal 200 and the lid 110 is ensured.

  The cylindrical portion 152 protrudes in a cylindrical shape downward from the lower surface of the terminal accommodating portion 153. The through hole 156 of the cylindrical portion 152 has the same shape as the through hole 123 of the positive electrode current collector 120. The through hole 156 is disposed so as to be continuous with the through hole 123 of the positive electrode current collector 120, and the shaft portion 220 of the positive electrode terminal 200 is inserted into the through holes 156 and 123. Further, the outer diameter of the cylindrical portion 152 is formed so as to be inserted into the through holes 172 and 112.

  The positive electrode first sealing member 150 as a whole is preferably made of an insulating member having lower rigidity than the lid 110. The positive electrode first sealing member 150 is formed of a resin such as PPS, PP, PE, PBT, PFA, and PEEK, for example.

  Next, the manufacturing method of the electrical storage element 10 is demonstrated.

  First, as shown in FIG. 4, the cylindrical portion 152 of the positive electrode first sealing member 150 is inserted into the through hole 112 of the lid 110. Next, the shaft portion 220 of the positive electrode terminal 200 is inserted into the through hole 156 of the positive electrode first sealing member 150. Thereafter, the cylindrical portion 152 of the positive electrode first sealing member 150 is inserted into the through hole 172 of the positive electrode second sealing member 170, and then the shaft portion 220 of the positive electrode terminal 200 is inserted into the through hole 123 of the positive electrode current collector 120. Insert.

  From this state, when the shaft portion 220 of the positive electrode terminal 200 is caulked, the tip portion 230 of the shaft portion 220 is pressed so as to spread outward, and is in close contact with the surface of the current collector body 121 over the entire circumference. Thereby, the adhesiveness of the front-end | tip part 230 of the axial part 220 and the collector main body part 121 is improved. In addition, due to this caulking, the distal end portion 230 of the shaft portion 220 and the bus bar connecting portion 210 are connected to the current collector body portion 121 of the positive electrode current collector 120, the positive electrode first sealing member 150, and the positive electrode second seal. The member 170 and the lid 110 are clamped in the Z-axis direction. Thereby, the space | interval of the cover body 110 and the bus-bar connection part 210 becomes narrow, the 1st protrusion 154 is compressed in the 1st recessed part 114, and the 2nd protrusion 155 is compressed in the 2nd recessed part 212. The As a result, the state shown in FIG. 3 is obtained.

  In the same process, the negative electrode first sealing member 160, the negative electrode second sealing member (not shown), the negative electrode current collector 130, and the negative electrode terminal 201 are also attached to the negative electrode side of the lid 110.

  Next, 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 accommodated in the container body 111 of the container 100, the lid body 110 is welded to the container body 111, and the container 100 is assembled. Next, the electrolytic solution is injected from a liquid injection port (not shown), and then a liquid injection stopper is welded to the lid 110 to close the liquid injection port, whereby the power storage device 10 shown in FIG. 1 is manufactured.

  As described above, according to the present embodiment, the first facing surface 1101 of the lid 110 is provided with the first recess 114 that accommodates the first protrusion 154 in a compressed state, and the first terminal 200 of the positive electrode terminal 200 is provided. The second facing surface 2102 is provided with a second recess 212 that accommodates the second protrusion 155 in a compressed state. Thereby, even if the protrusions of the first protrusion 154 and the second protrusion 155 remain after compression, the first recess 114 and the second recess 212 are accommodated, and the parallelism between the positive electrode terminal 200 and the lid 110 is ensured. can do. Therefore, it is possible to suppress an assembly failure caused by the protrusions (first protrusion 154 and second protrusion 155) of the positive electrode first sealing member 150.

  In addition, since the first protrusion 154 and the second protrusion 155 are arranged at a position where they overlap in a plan view, the force acting on the first protrusion 154 and the second protrusion 155 when compressed is viewed in a plan view. It can be given evenly. Therefore, stability after compression can be improved.

(Modification 1)
Next, Modification 1 according to the embodiment will be described. In the said embodiment, the case where both the 1st recessed part 114 and the 2nd recessed part 212 were provided in the electrical storage element 10 was demonstrated and demonstrated. However, the power storage element only needs to include at least one of the first recess 114 and the second recess 212.

  In the first modification, a power storage element that includes the first recess 114 and does not include the second recess 212 will be described. In Modification 2 described below, a power storage device that includes the second recess 212 and does not include the first recess 114 will be described, contrary to Modification 1.

  In the following description, parts different from the above embodiment will be mainly described, and the same parts as those in the above embodiment may be denoted by the same reference numerals and description thereof may be omitted.

  FIG. 8 is a cross-sectional view showing a fixing structure of the electricity storage device according to the first modification. Specifically, FIG. 8 corresponds to FIG.

  As shown in FIG. 8, in the lid 110 </ b> A of the first modification, the first facing surface 1101 a is a flat surface and does not include the first recess. Here, the compressive force which acts on the 1st protrusion 154 and the 2nd protrusion 155 by caulking is not equal. For this reason, even if the 1st protrusion 154 of the positive electrode 1st sealing member 150 is completely compressed by the 1st opposing surface 1101a of 110 A of lids, it is assumed that the 2nd protrusion 155 is not fully compressed. The However, even if the second protrusion 155 remains protruding to some extent after compression, the protrusion is accommodated by the second recess 212. That is, in such a case, the parallelism between the positive electrode terminal 200 and the lid 110A can be ensured only by the second recess 212, and assembly failure caused by the second protrusion 155 can be suppressed. .

(Modification 2)
Next, Modification 2 according to the embodiment will be described.

  FIG. 9 is a cross-sectional view illustrating the fixing structure of the electricity storage device according to the second modification, and corresponds to FIG. 3.

  As shown in FIG. 9, in the positive electrode terminal 200 </ b> B of the second modification, the second facing surface 2102 b is a flat surface and does not include the second recess. As described above, the compressive force acting on the first protrusion 154 and the second protrusion 155 by caulking is not uniform. For this reason, even if the 2nd protrusion 155 of the positive electrode 1st sealing member 150 is completely compressed by the 2nd opposing surface 2102b of the positive electrode terminal 200B, it is assumed that the 1st protrusion 154 is not fully compressed. The However, even if the first protrusion 154 remains protruding to some extent after compression, the protrusion is accommodated by the first recess 114. That is, in such a case, the parallelism between the positive electrode terminal 200 </ b> B and the lid body 110 can be ensured only by the first recess 114, and assembly failure due to the first protrusion 154 can be suppressed. .

(Modification 3)
In the said embodiment, the case where the 1st protrusion 154 and the 2nd protrusion 155 were provided in the positive electrode 1st sealing member 150 was illustrated. In Modification 3, a case where the first protrusion and the second protrusion are provided on the positive electrode second sealing member will be described as an example.

  FIG. 10 is a cross-sectional view illustrating a schematic configuration of a fixing structure according to Modification 3, and corresponds to FIG. 3. FIG. 11 is a cross-sectional view illustrating a state before the fixing structure according to Modification 3 is fixed, and corresponds to FIG. 4.

  As shown in FIGS. 10 and 11, the positive electrode first sealing member 150C is formed of a single resin as a whole, and the first surface 1531c and the second surface 1512c are formed in a plane. That is, the positive electrode first sealing member 150 </ b> C in Modification 3 does not include the first protrusion and the second protrusion.

  Further, the lower surface of the positive electrode terminal 200C is a flat surface and does not include the second recess.

  Although the upper surface of the lid 110C is a flat surface, the lower surface is a first facing surface 1103 that faces the first surface of the positive electrode second sealing member 170C. An annular first concave portion 118 surrounding the through hole 112 is formed on the first facing surface 1103.

  The upper surface of the current collector main body 121c of the positive electrode current collector 120C is a second facing surface 1212 that faces the second surface 1702 of the positive electrode second sealing member 170C. An annular second concave portion 124 surrounding the through hole 123 is formed on the second facing surface 1212.

  The outer upper surface of the positive electrode second sealing member 170C is a first surface 1701 that faces the lid 110C. A first protrusion 174 that surrounds the shaft portion 220 of the positive electrode terminal 200 is formed on the first surface 1701. Specifically, the first protrusion 174 is a protrusion having a semi-elliptical shape in cross section. The first protrusion 174 is formed in an annular shape centering on the axial center of the cylindrical portion 152 at a position accommodated in the first recess 118 of the lid 110C. The protrusion amount of the first protrusion 174 is set larger than the depth of the first recess 118.

  The upper surface in the recess 171 in the positive electrode second sealing member 170C is a second surface 1702 opposite to the first surface 1701 and facing the positive electrode current collector 120C. A second protrusion 175 that surrounds the shaft portion 220 of the positive electrode terminal 200 is formed on the second surface 1702. Specifically, the second protrusion 175 is a protrusion that is semicircular in sectional view. The second protrusion 175 is formed in an annular shape centering on the axial center of the cylindrical portion 152 at a position accommodated in the second recess 124 of the positive electrode current collector 120C. And when the 1st surface 1701 and the 2nd surface 1702 are planarly viewed, the 1st protrusion 174 and the 2nd protrusion 175 are arrange | positioned in the position which overlaps. The protrusion amount of the second protrusion 175 is set larger than the depth of the second recess 124.

  That is, even in the case of the third modification, after caulking, as shown in FIG. 11, the first protrusion 174 with the protrusion remaining is accommodated in the first recess 118 with the first protrusion 174 compressed. Can do. Similarly, in a state where the second protrusion 175 is compressed, the second protrusion 175 in which the protrusion remains can be accommodated in the second recess 124. Thereby, the parallelism with the collector main-body part 121c of the positive electrode collector 120C and the cover body 110C is securable. Therefore, it is possible to suppress an assembly failure caused by the protrusions (the first protrusion 174 and the second protrusion 175) of the positive electrode second sealing member 170C.

  Note that the positive electrode second sealing member 170C and the positive electrode first sealing member 150 described above may be used simultaneously. Thereby, parallelism can also be ensured while exhibiting high airtightness at each of the positive electrode terminal 200 side and the positive electrode current collector 120 side.

  In addition, the electricity storage device according to Modification 3 may include at least one of the first recess 118 and the second recess 124.

(Other embodiments)
The sealing member, the power storage element, and the like according to the embodiment of the present invention and the modifications thereof have been described above, but the present invention is not limited to the above-described embodiment and the modifications thereof. In other words, 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-described embodiment and its modification, 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 and its modification, although the positive electrode terminal 200 with which the bus-bar connection part 210 and the axial part 220 were integrally molded was illustrated, a bus-bar connection part and an axial part are separate bodies, Comprising: The positive electrode terminal integrated may be sufficient.

  Moreover, in the said embodiment and its modification, the case where the 1st protrusion parts 154 and 174 and the 2nd protrusion parts 155 and 175 each enclose the axial part 220 by single was illustrated. However, the first protrusion and the second protrusion may surround the shaft part 220 in multiples. In this case, the multiple first protrusions may be collectively accommodated by the single first recess, or the multiple first protrusions may be individually accommodated by the multiple first recesses. The same applies to the second protrusion and the second recess.

  Moreover, in the said embodiment, the planar view shape of each of the first protrusions 154 and 174 and the second protrusions 155 and 175 may be any shape as long as it is not an annular shape. Other planar shapes include, for example, a polygonal shape such as a triangle and a quadrangle, and an elliptical shape.

  Moreover, in the said embodiment, the case where the 1st protrusion parts 154 and 174 and the 2nd protrusion parts 155 and 175 were cross-sectional view semi-elliptical shapes was illustrated. However, the first protrusion and the second protrusion may have any cross-sectional shape as long as they protrude. Examples of other cross-sectional shapes include polygonal shapes such as triangles and quadrangles, and semicircular shapes. Further, the cross-sectional shapes of the first concave portion and the second concave portion may be any shape as long as the first protrusion and the second protrusion can be compressed and accommodated, respectively.

  Moreover, although it is desirable that the first protrusion and the second protrusion have an annular shape that is continuous as a whole, the outer appearance may be generally annular. Specifically, the first protrusion and the second protrusion may have gaps intermittently in the circumferential direction.

  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, 110C Cover body 111 Container main body 112,123,156,172 Through-hole 113 Protrusion 114,118 1st recessed part 120,120C Positive electrode collector (collector)
121, 121c Current collector main body 122 Electrode body connecting portion 124, 212 Second recess 130 Negative electrode current collector 140 Electrode body 150, 150C Positive electrode first sealing member 151 Recess 152 Cylindrical portion 153 Terminal accommodating portion 154, 174 First Projection 155, 175 Second projection 160 Negative electrode first sealing member 161 Recess 170, 170C Positive electrode second sealing member 171 Recess 200, 200B, 200C Positive electrode terminal 201 Negative electrode terminal 210 Busbar connection part 220 Shaft part 230 Tip part 1101 1101a, 1103 1st opposing surface 1212, 2102, 2102b 2nd opposing surface 1512, 1512c, 1702 2nd surface 1531, 1531c, 1701 1st surface H1, H2 Protrusion amount D1, D2 Depth

Claims (3)

A storage element comprising a terminal provided in a container and a current collector electrically connected to the terminal,
A sealing member disposed between the terminal or the current collector and the container;
The sealing member is
A first surface facing the container;
A second surface opposite to the first surface and facing the terminal or the current collector;
The first surface is formed with a first protrusion that surrounds the shaft portion of the terminal,
The second surface is formed with a second protrusion that surrounds the shaft portion of the terminal,
The first protrusion and the second protrusion are compressed when the sealing member is compressed between the terminal or the current collector and the container,
The power storage element is
A first recess formed on a first facing surface of the container facing the first surface and accommodating the first protrusion in a compressed state; and opposed to the second surface of the terminal or the current collector. An electricity storage device comprising at least one of a second recess formed on the second facing surface and accommodating the second protrusion in a compressed state. The electricity storage device according to claim 1, comprising the first recess and the second recess. The power storage element according to claim 1, wherein the first protrusion and the second protrusion overlap each other when the shaft portion is viewed in the axial direction.

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