JP6015582B2 - Electricity storage element - Google Patents

Description

  The present invention relates to power storage elements such as secondary batteries and other batteries.

  Secondary batteries are widely used as power sources for electronic devices such as mobile phones and IT devices, as well as for replacing primary batteries. In particular, since non-aqueous electrolyte secondary batteries represented by lithium ion batteries have high energy density, they are also being applied to industrial large electric devices such as electric vehicles.

  Conventionally, in a non-aqueous electrolytic secondary battery, in order to take out the electric power generated by the electrode body disposed inside the container, the current collector is electrically connected to the positive electrode and the negative electrode of the electrode body and disposed inside the container. There is a connecting portion for connecting the member and an electrode terminal outside the container. The connecting portion is integrally formed with the electrode terminal, and penetrates the lid portion of the container in order to connect the current collecting member inside the container and the electrode terminal outside the container. For this reason, the cover part is provided with a through hole through which the connection part passes.

  The container is often made of metal, and if the connection part penetrates the container without insulation, it is short-circuited by the container, so the part where the through hole of the container is formed, the electrode terminal, and the connection part And the current collecting member must be insulated. In addition, the container contains the electrolytic solution together with the electrode body, and it is necessary to prevent the electrolytic solution from leaking from the through hole to the outside of the container.

  In the conventional power storage element, in order to insulate the container from the electrode terminal, the connecting portion, and the current collecting member, and to prevent the electrolyte from leaking from the through hole of the container, in the portion where the through hole of the container is formed An insulating sealing material is provided over the outside and inside of the container. With the insulating sealing material covering the part where the through-hole of the container is formed over the inside and outside of the container, the electrode terminal outside the container and the current collecting member inside the container are pressure-bonded by the connecting portion, so that the electrode The insulation between the terminal, the connecting portion, and the current collecting member and the container and the seal are made compatible.

  In the electric storage element having such a configuration, in Patent Document 1, an annular protrusion that surrounds the connection portion is formed on the electrode terminal. In patent document 1, the improvement of a sealing performance is aimed at by forming an annular projection part in an electrode terminal. Patent Document 2 discloses a battery having a configuration in which a convex portion is provided at a location where an insulating member is crimped in order to improve sealing performance.

JP 2008-251213 A

  However, the above-described techniques cannot sufficiently improve the sealing performance.

  Therefore, the present invention has been made in view of such a situation, and an object thereof is to provide a power storage element that can improve the sealing performance in the vicinity of the electrode terminal of the power storage element.

  To achieve the above object, a container, an electrode body housed in the container, an electrode terminal, a current collecting member for electrically connecting the electrode terminal and the electrode body, the container and the electrode A storage element including an insulating member that insulates the terminal, wherein the electrode terminal penetrates the container and is connected to the current collecting member at a columnar connection portion and an end portion of the connection portion A plate-shaped terminal body disposed outside the container, the insulating member includes a plate-shaped member disposed between the container and the terminal body, And a sealing agent provided between at least one of the terminal body and the container and the insulating member, wherein the plate-like member is provided in an annular shape surrounding the connecting portion, and the plate-like member A convex portion projecting in a direction intersecting with the convex portion, It has a holding portion capable of holding the liquid to the tip.

  According to this, on the plate-like member of the insulating member, a convex portion that is provided in an annular shape surrounding the connecting portion and protrudes in a direction intersecting the plate-like member is formed, and liquid is applied to the tip of the convex portion. A holding portion capable of holding is formed. For this reason, when a liquid sealing agent is applied to the insulating member, the sealing agent can be prevented from flowing from the tip of the convex portion. Thereby, a sufficient amount of the sealing agent can be held at the tip of the convex portion, and the sealing performance around the electrode terminal can be improved.

  Further, the holding portion may be a groove portion formed along the annular direction of the convex portion at the tip of the convex portion.

  According to this, since the groove portion is formed at the tip of the convex portion, the liquid sealing agent can be held in the groove portion when the liquid sealing agent is applied to the insulating member. For this reason, it can prevent that a sealing agent flows from the front-end | tip of a convex part, and can improve the sealing performance around an electrode terminal.

  Further, the holding part may be a plurality of protrusions formed continuously along the annular direction of the convex part.

  According to this, since the plurality of protrusions are formed at the tip of the convex portion, when the liquid sealant is applied to the insulating member, the liquid sealant can be held between the plurality of protrusions. . For this reason, it can prevent that a sealing agent flows from the front-end | tip of a convex part, and can improve the sealing performance around an electrode terminal.

  In addition, at least one of the terminal main body and the container has the first distance between the terminal main body and the container at the first position of the terminal main body at the second position closer to the connecting portion than the first position. You may form so that it may become smaller than the 2nd space | interval of a terminal main body and the said container.

  According to this, the shape of at least one of the terminal body and the container is such that the first distance between the terminal body and the container at the first position is a distance between the terminal body and the container at the second position closer to the connecting portion than the first position. Less than the second interval. The insulating member is sandwiched between the terminal body and the container and receives a pressing force from both. That is, in the space in which the insulating member is arranged, the distance between the terminal body and the container at the first position, which is a position far from the electrode terminal connection portion, is narrow in the direction intersecting the direction of the pressing force. . For this reason, even if an insulating member thermally expands in a high temperature environment, it can suppress that an insulating member expands toward the direction which cross | intersects the direction of a pressing force. Thereby, even if the insulating member is thermally expanded, the insulating member can be kept within a predetermined range, so that the sealing performance in the vicinity of the electrode terminal can be sufficiently maintained.

  Further, at least one of the terminal main body and the container may be formed such that a distance between the terminal main body and the container becomes smaller from the second position toward the first position.

  According to this, at least one of the terminal main body and the container is formed so that the distance between the terminal main body and the container decreases as the distance from the connection portion increases between the first position and the second position. For this reason, during the thermal expansion of the insulating member, the force applied to the insulating member between the first position and the second position is dispersed when the insulating member expands in the direction intersecting the direction of the pressing force. be able to. Note that this force is specifically a force that prevents the insulating member from expanding in a direction farther from the connection portion, and is a force directed in a direction closer to the connection portion. Thereby, compared with the structure of the structure where the space | interval between a terminal main body and a container becomes small rapidly, it can prevent that force is largely applied to the specific part of a terminal main body, a container, or an insulation member, and a terminal It is possible to prevent the main body, the container, or the insulating member from being damaged.

  In addition, at least one of the terminal main body and the container has a container-side surface of the terminal main body between the first position and the second position, with respect to the terminal main body-side surface of the container. It may be inclined linearly.

  According to this, the container side surface of the terminal body is inclined linearly with respect to the terminal body side surface of the container. For this reason, at the time of thermal expansion of the insulating member, when the insulating member expands in the direction intersecting the direction of the pressing force, the insulating member between the first position and the second position is close to the connection portion. The force directed in the direction can be evenly distributed at least between the first position and the second position. Thus, since the force applied to the terminal body, the container, or the insulating member can be made uniform between the first position and the second position, the force applied at each position can be minimized. For this reason, it can prevent more effectively that a terminal main part, a container, or an insulating member is damaged.

  In addition, at least one of the terminal body and the container has a stepwise difference between the first interval in the first region including the first position and the second interval in the second region including the second position. Also good.

  According to this, the shape of at least one of the terminal main body and the container is formed such that the first interval in the first region and the second interval in the second region are stepwise different. For this reason, in at least one of the terminal body and the container, a shape in which the first interval is narrow can be easily manufactured.

  In addition, the container has a third distance between the connection portion and the container at a third position of the container at a portion facing the connection portion, the third distance between the container and the third position. You may form so that it may become smaller than the 4th space | interval of the said connection part and the said container in four positions.

  According to this, the shape of the container is such that the third distance between the connection portion and the container at the third position is the fourth distance between the connection portion and the container at the fourth position on the outer side of the container with respect to the third position. Smaller than. The insulating member is sandwiched between the connecting portion and the container, and when thermally expanded, the insulating member tends to expand in all directions. At this time, since the third interval at the third position, which is the position on the inner side of the container, is narrower than the fourth interval, the insulating member expands toward the inner side of the container even if the insulating member thermally expands. Can be suppressed. Thereby, when the insulating member is thermally expanded, the insulating member can be kept within a predetermined range even in the axial direction of the connecting portion, and thus the sealing performance in the vicinity of the electrode terminal can be sufficiently maintained.

  In addition, the container may be formed so that a distance between the connection portion and the container becomes smaller from the fourth position toward the third position.

  According to this, the container is formed so that the distance between the connecting portion and the container decreases as the distance from the terminal body increases between the third position and the fourth position. For this reason, during the thermal expansion of the insulating member, when the insulating member expands in the direction intersecting the direction of the pressing force, the force applied to the insulating member between the third position and the fourth position is dispersed. be able to. Specifically, this force is a force that prevents the insulating member from expanding toward the inside of the container, and is a force that is directed toward the terminal body. Thereby, compared with the structure of the structure where the space | interval between a connection part and a container becomes small rapidly, it can prevent that force is largely applied to the specific site | part of a terminal main body, a container, or an insulating member, and a terminal It is possible to prevent the main body, the container, or the insulating member from being damaged.

  In addition, even if the surface of the container that faces the connection portion of the container is inclined linearly with respect to the surface of the connection portion between the third position and the fourth position. Good.

  According to this, the connection part side surface of the container is inclined linearly with respect to the surface of the connection part. For this reason, at the time of thermal expansion of the insulating member, when the insulating member expands in the direction intersecting the direction of the pressing force, the insulating member between the third position and the fourth position is close to the connecting portion. The directionally directed force can be equalized at least between the third position and the fourth position. Thus, since the force applied to the terminal body, the container, or the insulating member can be made uniform between the third position and the fourth position, the force applied at each position can be minimized. For this reason, it can prevent that a terminal body, a container, or an insulating member breaks.

  Further, the electrode terminal may be sealed with the insulating member between a portion where the through hole of the container is formed and the terminal body by pressure-bonding the insulating member and the container.

  According to this, the insulating member and the container are pressure-bonded by the electrode terminal, whereby the portion where the through hole of the container is formed and the terminal body are sealed with the insulating member. For this reason, the insulating member is in a state in which a pressing force is always applied between the terminal body and the container by the electrode terminal. Even in such an insulating member that is always subjected to a pressing force and is likely to expand in a direction that intersects the pressing force when thermally expanded, the space in the direction intersecting the pressing force is narrowed. Therefore, the expansion of the insulating member in the direction can be suppressed.

  According to the electricity storage device of the present invention, the sealing performance in the vicinity of the electrode terminal of the electricity storage device can be improved.

It is a perspective view which shows the external appearance of the electrical storage element which concerns on Embodiment 1 of this invention. It is a disassembled perspective view which shows the typical structure of an electrical storage element. It is the enlarged view to which the electrode terminal periphery was expanded in III-III sectional drawing of the disassembled perspective view of the electrical storage element of FIG. It is the enlarged view to which the part of area | region A1 of FIG. 3 was expanded. 5A is an enlarged view of the vicinity of the electrode terminal in the IV-IV cross-sectional view of the electricity storage device of FIG. 1, and FIG. 5B is a region A2 in FIG. It is the enlarged view to which the part of was expanded. FIG. 4 is an enlarged view of an area A1 in FIG. 3 according to a modification of the first embodiment. FIG. 7A is an enlarged view of a section around the electrode terminal of the energy storage device according to the second embodiment, and FIG. 7B shows a region A3 in FIG. It is an enlarged view.

(Knowledge that became the basis of the present invention)
The present inventor has found that the following problems occur with respect to the electricity storage device described in the “Background Art” column.

  In general power storage elements, in order to improve the sealing performance between the insulating member and the electrode terminal or the container, a sealing agent is often provided on one of the insulating member and the electrode terminal or the container. . This sealing agent is applied in a liquid state to one of the surfaces of the insulating member and the electrode terminal or the container, and then the solvent constituting the liquid sealing agent is vaporized to form a solid elastic body. . That is, when applying the sealing agent, the sealing agent is in a liquid state. Therefore, as in Patent Document 1 or 2, in the case of an energy storage device provided with a convex portion (protrusion portion) for the purpose of improving sealing performance, when the sealing agent is applied to the convex portion, the solvent of the sealing agent is The sealant flows from the tip of the convex portion before vaporization. This makes it difficult to provide a sufficient amount of sealing agent at the tip of the convex portion. That is, the sealing performance in the vicinity of the electrode terminal of the power storage element cannot be sufficiently improved.

  Hereinafter, embodiments 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 the 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 of the present invention are described as optional constituent elements that constitute a more preferable embodiment.

(Embodiment 1)
FIG. 1 is a perspective view showing an external appearance of the energy storage device according to Embodiment 1 of the present invention. FIG. 2 is an exploded perspective view showing a schematic configuration of the power storage element.

  As shown in FIG. 1, the electricity storage device 100 according to the first embodiment electrically connects the container 110, the electrode body 170 accommodated in the container 110, the electrode terminal 130, the electrode terminal 130, and the electrode body 170. A current collecting member 160 connected to each other, an external insulating sealing material 120 that insulates the container 110 from the electrode terminal 130, and an internal insulating sealing material 150 that insulates the container 110 from the current collecting member 160.

  The container 110 includes a lid part 111 and a container main body 112. The lid portion 111 is a long plate-like member that is long in the Y-axis direction (described later). The container body 112 is a member having an opening 114 at one end of a rectangular cylindrical member and a bottom at the other end. In the first embodiment, the arrangement direction of the container body 112 and the lid portion 111 is the vertical direction (Z-axis direction in FIG. 1), and the arrangement direction of the positive electrode terminal and the negative electrode terminal is the left-right direction (Y in FIG. 1). A vertical direction and a direction perpendicular to the left-right direction are defined as the front-rear direction (X-axis direction in FIG. 1).

  The lid portion 111 is formed with through holes 113 penetrating the electrode terminals 130 at both ends in the longitudinal direction. In FIG. 1, only the through hole 113 on the positive electrode side is shown, and the through hole on the negative electrode side is not shown because it is hidden behind an insulating sealing material described later.

  The electrode body 170 is formed by being wound into a long cylindrical shape while being laminated so that a separator is sandwiched between a positive electrode and a negative electrode which are band-shaped electrodes. The electrode body 170 is housed in the container 110 in such an orientation that the winding axis direction coincides with the Y-axis direction and the long axis of the cross-sectional oval shape coincides with the Z-axis direction. The positive electrode and the negative electrode are wound in a long cylindrical shape around the winding axis while being displaced from each other in the winding axis direction. The electrode body 170 has projecting portions 171 and 172 that project from the separator toward the outside in the winding axis direction (Y-axis direction) of the electrode body 170 with a predetermined width at both ends thereof. That is, the electrode body 170 has a positive-side protruding portion 171 in which the positive electrode protrudes from the separator at one end in the winding axis direction, and a negative-side protruding portion 172 in which the negative electrode protrudes from the separator at the other end. Further, the positive electrode-side protruding portion 171 and the negative electrode-side protruding portion 172 are not formed with an active material, and the metal foil as the base material is exposed. In other words, the protruding portion 171 on the positive electrode side exposes an aluminum foil that is a positive electrode base material on which the positive electrode active material layer is not formed, and the protruding portion 172 on the negative electrode side has a negative electrode on which the negative electrode active material layer is not formed. The copper foil which is a base material is exposed. A positive electrode side current collecting member 160 and a negative electrode side current collecting member 164 are electrically connected to the positive electrode side protruding portion 171 and the negative electrode side protruding portion 172, respectively.

  The upper end portion of the current collecting member 160 has a plate-like configuration (a plate portion 161 described later) parallel to the upper surface of the electrode body 170 (that is, parallel to the XY plane). A through hole 162 is formed in the configuration. Further, the current collecting member 160 has a configuration (an arm portion 163 to be described later) that is connected and fixed by ultrasonic welding or the like at the positive-side protruding portion 171 that is one end of the electrode body 170 in the winding axis direction. The negative electrode side current collecting member 164 has the same configuration and is formed of copper or a copper alloy. Since the positive current collecting member 160 and the negative current collecting member 164 have the same configuration, only the positive current collecting member 160 will be described below, and the description of the negative current collecting member 164 will be omitted. .

  The internal insulating sealing material 150 is an insulating member that insulates the container 110 and the current collecting member 160 by being disposed between the lid portion 111 and the current collecting member 160. That is, the internal insulating sealing material 150 is an insulating member that is disposed inside the container 110 and insulates the container 110 from the electrode body 170 that is electrically connected via the current collecting member 160. Further, the internal insulating sealing material 150 is pressed together with the electrode terminal 130 and the external insulating sealing material 120 to the through hole 113 formed in the lid portion 111 of the container 110, thereby sealing the through hole 113. It also functions as a sealing material (packing). The internal insulating sealing material 150 is made of synthetic resin or the like and has insulating properties and elasticity. The internal insulating sealing material 150 is formed with a through hole 151 that is penetrated by a connection portion 132 of an electrode terminal 130 described later, along with the through hole 113 of the lid portion 111 and the through hole 162 of the current collecting member 160.

  The external insulating sealing material 120 is an insulating member that insulates the electrode terminal 130 from the container 110 by being disposed between the terminal main body 131 (see below) of the electrode terminal 130 and the lid portion 111. That is, the external insulating sealing material 120 is disposed outside the container 110 and is an insulating member for insulating the container 110 from the electrode body 170 that is electrically connected via the electrode terminal 130 and the current collecting member 160. It is. The external insulating sealing material 120 is a member disposed between the terminal main body 131 and the lid portion 111 of the container 110, and the through hole 113 of the connection portion 132 and the lid portion 111 of the container 110 is formed. It is the member arrange | positioned over the part currently formed. Further, the external insulating sealing material 120 is sealed together with the electrode terminal 130 and the internal insulating sealing material 150 against the through hole 113 formed in the lid portion 111 of the container 110, thereby sealing the through hole 113. It also functions as a sealing material (packing). The external insulating sealing material 120 is arranged on the upper side of the lid portion 111 and is continuously formed from a plate-like member 121 where the through-hole 124 is formed and a portion where the through-hole 124 of the plate-like member 121 is formed, And a cylindrical cylindrical portion 123 extending below the plate-like member 121. That is, the external insulating sealing material 120 includes the cylindrical portion 123 and the plate-like member 121 that extends in the direction intersecting the axis of the cylindrical portion 123 and toward the outside of the cylindrical portion 123. The plate-like member 121 has a convex portion 125 that is provided in an annular shape surrounding the connection portion 132 of the electrode terminal 130 and protrudes in a direction intersecting the plate-like member 121. That is, the convex portion 125 is provided in an annular shape that surrounds the outside of the through hole 124 formed in the plate-like member 121. In the first embodiment, the convex portions 125 are formed on both sides of the plate member 121 in the Z-axis direction.

  The external insulating sealing material 120 is a synthetic resin member similar to the internal insulating sealing material 150. The through holes 124 formed in the external insulating sealing material 120 are the through holes 113 formed in the lid portion 111, the through holes 151 formed in the internal insulating sealing material 150, and the through holes formed in the current collecting member 160. Along with 162, it is penetrated by a connecting portion 132 of an electrode terminal 130 to be described later.

  The cylindrical portion 123 of the external insulating sealing material 120 is formed on the side facing the lid portion 111 (that is, the lower side of the plate-like member 121), and the through hole 124 and the inner edge of the cylindrical portion 123 coincide with each other. ing. The cylindrical portion 123 has an outer shape corresponding to the through hole 113 and is fitted into the through hole 113. Accordingly, the cylindrical portion 123 is sandwiched between the through hole 113 formed in the lid portion 111 of the container 110 and the connection portion 132 of the electrode terminal 130. That is, the external insulating sealing material 120 is sandwiched between the terminal body 131 of the electrode terminal 130 and the lid portion 111 of the container 110, and forms the connection portion 132 of the electrode terminal 130 and the through hole 113 of the container 110. The electrode terminal 130 and the container 110 are insulated by being sandwiched between the portions. Further, a frame body 122 is formed on the upper side of the plate-like member 121 of the external insulating sealing material 120, and the frame body 122 is formed outside the through hole 124 formed in the plate-like member 121.

  The electrode terminal 130 penetrates the container 110 and is connected to the current collecting member 160 and is connected to the current collector 160. The plate-shaped terminal body is disposed outside the container 110 at the end of the connection part 132. 131. Note that the connecting portion 132 extends inward of the container 110. The terminal body 131 has a planar shape in which the outer edge shape corresponds to the inner edge shape of the frame body 122. The connecting portion 132 serves to electrically connect the terminal body 131 and the current collecting member 160 and mechanically join the lid portion 111 and the electrode body 170. Moreover, the electrode terminal 130 arrange | positioned at the positive electrode side is comprised from aluminum or aluminum alloy, and the electrode terminal arrange | positioned at the negative electrode side is comprised from copper or a copper alloy.

  Specifically, the electrode terminal 130 is connected to the storage element 100 and the external load by welding and fixing a terminal of an external load (not shown) (that is, a device that consumes electrical energy of the storage element 100) to the surface of the terminal body 131. This is a member for completing the electrical connection. Alternatively, the electrode terminal 130 is electrically connected between the storage elements 100 by welding and fixing the terminal main body 131 of each battery with a conductive member such as a bus bar in a state where a plurality of storage elements 100 (not shown) are arranged side by side. It is a member for completing.

  In the electrode terminal 130, the terminal main body 131 and the connecting portion 132 may be made of the same material by forging, casting, or the like. The electrode terminal 130 includes a terminal body 131 and a connection portion 132 that are independent of each other, and is formed by integrally molding two different or similar materials constituting the terminal body 131 and the connection portion 132. May be.

  Next, with reference to FIGS. 3 to 5, the configuration around the electrode terminal of the energy storage device according to the first embodiment will be described in more detail. FIG. 3 is an enlarged view of the vicinity of the electrode terminal in the III-III cross-sectional view of the exploded perspective view of the energy storage device of FIG. FIG. 4 is an enlarged view of an area A1 in FIG. (A) of FIG. 5 is the enlarged view which expanded the electrode terminal periphery among the IV-IV sectional drawings of the electrical storage element of FIG. FIG. 5B is an enlarged view of a region A2 in FIG.

  As shown in FIGS. 3 to 5, the configuration around the electrode terminal 130 of the energy storage device 100 includes the electrode terminal 130, the external insulating sealing material 120, the lid 111, the internal insulating sealing material 150, and the current collecting member 160 from the top. The plate portions 161 are stacked in this order. The external insulating sealing material 120 includes a plate-shaped member 121, a lid portion 111, and an internal insulating sealing material 150 that overlap each other, and a cylindrical portion 123 formed in the lid portion 111. It arrange | positions in the state penetrated to the through-hole 151 formed in the material 150. FIG. The end surface of the cylindrical portion 123 is flush with the lower surface of the internal insulating sealing material 150 and is in contact with the upper surface of the plate portion 161 of the current collecting member 160 together with the lower surface of the internal insulating sealing material 150. And the shape of the inner periphery of the cylinder part 123 of the external insulation sealing material 120 and the through-hole 162 of the current collection member 160 are the same size and the same shape. The cylindrical portion 123 and the through hole 162 are penetrated by the connection portion 132 of the electrode terminal 130. That is, the outer periphery of the connection part 132, the inner periphery of the cylinder part 123, and the part in which the through-hole 162 is formed are in contact with each other.

  As shown in FIG. 3, the external insulating sealing material 120 is formed with convex portions 125 that protrude from the plate-like member 121 toward both sides in the Z-axis direction. As shown in FIG. 4, the convex portion 125 is provided with a groove portion 125 a formed continuously along the annular direction of the convex portion 125 at the tip thereof. That is, the convex part 125 has the groove part 125a as a holding | maintenance part which can hold | maintain a liquid at the front-end | tip. A sealing agent 180 is applied to the surface of the external insulating sealing material 120. That is, the sealing agent 180 is provided between at least one of the terminal body 131 and the lid portion 111 of the container 110 and the external insulating sealing material 120. Thereby, when the liquid sealing agent 180 is applied to the external insulating sealing material 120, the sealing agent 180 can be prevented from flowing from the tip of the convex portion 125. The groove part formed in the convex part 125 may not be continuously formed along the annular direction of the convex part 125, and may be intermittently formed along the annular direction. That is, the groove part should just be formed in the cyclic | annular direction of a convex part in the front-end | tip of a convex part.

  The sealing agent 180 is applied in a liquid state on the surface of the external insulating sealing material 120, and then the solvent constituting the liquid sealing agent 180 is vaporized to become a solid elastic body. The size of the groove 125a is such that the volume of the liquid that can be held in the groove 125a is larger than the volume obtained by multiplying the area of the convex 125 when viewed from the Z-axis direction by the thickness of the sealant 180 necessary for design. It is preferable to become.

  And the connection part 132 of the electrode terminal 130 is caulked at the tip in a state where it penetrates the cylindrical part 123 of the external insulating sealing material 120 and the through-hole 162 formed in the current collecting member 160, and the caulking end 133 is formed. Is done. That is, the caulking end 133 is formed by caulking the end of the electrode terminal 130 on the side opposite to the terminal body 131 of the connecting portion 132, and the inner diameter of the cylindrical portion 123 and the diameter of the through hole 162 of the current collecting member 160. The outer diameter is larger than

  Since the outer diameter of the caulking end 133 is larger than the diameter of each of the through holes 124, 113, 151, 162, the outer insulating sealing material 120, the lid portion 111, the inner insulating sealing material 150, and the current collecting member 160 are connected to the electrode terminal 130. By being sandwiched between the terminal body 131 and the caulking end 133, they are crimped to each other and fixed together. As a result, the electrode terminal 130 is bonded to the external insulating sealing material 120 and the lid portion 111 of the container 110, so that the portion between the portion of the container 110 where the through hole 113 is formed and the electrode terminal 130 are sealed with the external insulating seal. Sealing is performed with the stopper 120 and the internal insulating sealing material 150. At this time, as shown in a portion surrounded by a broken line in FIG. 5B, the convex portion 125 formed on the plate-like member 121 of the external insulating sealing material 120 is compressed by the electrode terminal 130 and the lid portion 111. Therefore, it will be in a crushed state. And even if the convex part 125 is crushed by the electrode terminal 130 and the cover part 111, the force (refer to the white arrow of FIG.5 (b)) which repels and returns is acting. As a result, the outer insulating sealing material 120 is sufficiently in close contact with the terminal main body 131 of the electrode terminal 130 and the lid portion 111 of the container 110, particularly at the convex portion 125. The electrode terminal 130 is electrically connected to the current collecting member 160 in a state of penetrating the lid 111 because the connecting portion 132 and the crimping end 133 are in contact with the current collecting member 160. In addition, since the side surface of the connection part 132 is covered with the cylinder part 123 of the external insulation sealing material 120, the insulation state is ensured between the cover part 111 and the connection part 132. FIG.

(Feature)
According to the energy storage device 100 according to the first embodiment, the plate-like member 121 of the external insulating sealing material 120 is provided in an annular shape surrounding the connecting portion 132 and protrudes in a direction intersecting the plate-like member 121. A convex part 125 is formed, and a groove part 125 a as a holding part capable of holding a liquid is formed at the tip of the convex part 125. For this reason, when the liquid sealing agent 180 is applied to the external insulating sealing material 120, it is possible to prevent the sealing agent 180 from flowing from the tip of the convex portion 125. Thereby, a sufficient amount of the sealing agent 180 can be held at the tip of the convex portion 125, and the sealing performance around the electrode terminal 130 can be improved.

  Further, according to the electricity storage device 100 according to the first exemplary embodiment, since the groove 125a is formed at the tip of the convex portion 125, when the liquid sealing agent 180 is applied to the external insulating sealing material 120, the groove 125a. The liquid sealant 180 can be held in the liquid crystal. For this reason, it can prevent that the sealing agent 180 flows from the front-end | tip of the convex part 125, and can improve the sealing performance of the electrode terminal 130 periphery.

(Modification)
According to power storage element 100 according to Embodiment 1 described above, groove 125a is formed as a holding portion at the tip of convex portion 125, but the holding portion is not limited to groove 125a. For example, like the external insulating sealing material 220 shown in FIG. 6, the holding portion is continuously provided at the tip of the convex portion 225 formed on the plate-like member 221 along the annular direction of the convex portion 225. A plurality of protrusions 225a may be formed. In addition, the size (height) of the plurality of protrusions 225a is necessary for designing the volume of the liquid held between the plurality of protrusions 225a to be the area of the protrusions 225 when viewed from the Z-axis direction. The volume is preferably larger than the volume multiplied by the thickness of the sealing agent 180. In FIG. 6, the number of the plurality of protrusions 225a is four. However, the number of the protrusions 225a is not limited to four as long as the plurality of protrusions 225a can hold the liquid. FIG. 6 is an enlarged view of an area A1 of FIG. 3 according to a modification of the first embodiment.

  According to this, since the plurality of protrusions 225a are formed at the tips of the protrusions 225, when the liquid sealing agent 180 is applied to the external insulating sealing material 120, the liquid between the plurality of protrusions 225a. The sealing agent 180 can be held. For this reason, it can prevent that the sealing agent 180 flows from the front-end | tip of the convex part 225, and can improve the sealing performance of the electrode terminal 130 periphery. Further, the holding unit may form a flat surface at the tip of the convex portion, and the flat surface may be used as the holding unit.

(Embodiment 2)
FIG. 7A is an enlarged view of an enlarged cross section around the electrode terminal of the energy storage device according to the second embodiment. FIG. 7B is an enlarged view of an area A3 in FIG.

  Note that, among the components of the electricity storage device 300 according to the second embodiment, the components different from the components of the electricity storage device 100 according to the first embodiment are the electrode terminals 330, the external insulating sealing material 320, and the container 310. Only the shape of the lid 311 is shown. For this reason, the same code | symbol is attached | subjected to the same component as the electrical storage element 100 which concerns on Embodiment 1, and detailed description is abbreviate | omitted.

  Next, the individual configuration of each unit will be described.

  As shown in FIG. 7, the terminal body 331 of the electrode terminal 330 is formed such that the first interval d1 is smaller than the second interval d2. Here, it is preferable that the first interval d1 is formed to be smaller than ½ of the second interval d2. The first interval d1 is the interval between the terminal body 331 and the lid 311 of the container 310 at the first position P1 of the terminal body 331. The second distance d2 is the distance between the terminal main body 331 and the lid portion 311 of the container 310 at the second position P2 that is closer to the connection portion 332 than the first position P1.

  In the second embodiment, the first position P1 is a position on the terminal main body 331 and the farthest position from the connection portion 332. In the second embodiment, the second position P2 is a position on the terminal main body 331 and is the closest position to the connecting portion 332. Note that the first position P1 and the second position P2 are not limited to the farthest position and the most recent position from the connection part 332 as described above, but the first position is closer to the connection part 132 than the second position. Any remote location is acceptable. That is, even in such a case, the first interval at the first position is smaller than the second interval at the second position. In this case, the distance between the terminal main body 331 and the lid 311 of the container 310 at a position farthest from the connection portion 332 in the terminal main body 331 which is a position different from the first position is different from the second position. It is good also as a structure smaller than the space | interval of the terminal main body 331 and the cover part 311 of the container 310 in the position nearest to the connection part 332 in the terminal main body 331 which is a position.

  In the second embodiment, the distance between the terminal main body 331 and the lid 311 of the container 310 is the distance between the lower surface of the terminal main body 331 and the upper surface of the lid 311 (all the planes matching the upper surface). Is the interval between.

  Further, the terminal main body 331 is formed so that the distance between the terminal main body 331 and the lid portion 311 of the container 310 becomes smaller from the second position P2 toward the first position P1. More specifically, in the terminal main body 331, the surface 331 a on the lid 311 side of the container 310 of the terminal main body 331 is the surface on the terminal main body 331 side of the container 310 between the first position P1 and the second position P2. It is inclined linearly with respect to 311a (that is, the upper surface).

  Further, the surface 321 a on the terminal main body 331 side of the external insulating sealing material 320 has an inclination corresponding to the surface 331 a on the lid 311 side of the container 310 of the terminal main body 331. The external insulating sealing material 320 is provided with a convex portion 325 that does not appear in FIG. 7 as in the convex portion 125 formed on the external insulating sealing material 120 of the first embodiment. . Note that, in the power storage element 300 according to the second embodiment, as in the power storage element 100 according to the first embodiment, as shown in the portion surrounded by the broken line in FIG. Since the convex portion 325 formed on the plate-like member 321 is compressed by the electrode terminal 330 and the lid portion 311, it is in a crushed state. Even if the convex portion 325 is crushed by the electrode terminal 330 and the lid portion 311, a force (see the white arrow in FIG. 7B) acts to repel and return to the protruding direction.

  The lid 311 of the container 310 is formed so that the third distance d3 is smaller than the fourth distance d4 at the part facing the connection part 332 (that is, the part where the through hole 313 is formed). ing. The third distance d3 is the distance between the connecting portion 332 and the lid portion 311 of the container 310 at the third position P3 of the lid portion 311 of the container 310. The fourth distance d4 is the distance between the connection portion 332 and the container at the fourth position P4 located on the outer side of the lid 311 of the container 310 with respect to the third position P3. That is, the through-hole 313 formed in the lid portion 311 of the container 310 is formed so that its diameter decreases as it goes inward of the container 310.

  In the second embodiment, the third position P3 is a position on the lid portion 311 of the container 310 and is the outermost position of the lid portion 311 of the container 310. In the second embodiment, the fourth position P4 is a position on the lid portion 311 of the container 310 and is the innermost position of the lid portion 311 of the container 310. The third position and the fourth position are not limited to the outermost position and the innermost position of the lid portion 311 of the container 310 as described above, but the third position is more than the fourth position. What is necessary is just the outside position.

  Further, the lid portion 311 of the container 310 is formed so that the distance between the connection portion 332 and the lid portion 311 of the container 310 becomes smaller from the fourth position P4 toward the third position P3. More specifically, the lid 311 of the container 310 has a connecting portion 332 between the third position P3 and the fourth position P4, the surface 311b facing the connecting portion 332 of the lid 311 of the container 310. It is inclined linearly with respect to the surface 332a.

(Feature)
According to the electricity storage device 300 according to the second embodiment, the terminal body 331 has a shape in which the first distance d1 between the terminal body 331 and the lid portion 311 of the container 310 at the first position P1 is greater than the first position P1. It is smaller than the second distance d2 between the terminal main body 331 and the lid 311 of the container 310 at the second position P2 close to the connecting portion 332. The external insulating sealing material 320 is sandwiched between the terminal body 331 and the container 310 and receives a pressing force from both. In other words, the space in which the external insulating sealing material 320 is disposed is the terminal body 331 and the container at the first position P1 which is a position far from the connection portion 332 of the electrode terminal 330 in the direction intersecting the direction of the pressing force. The space | interval with the cover part 311 of 310 is narrow. For this reason, even if the external insulating sealing material 320 is thermally expanded in a high-temperature environment, it is possible to suppress the external insulating sealing material 320 from expanding toward the direction intersecting the direction of the pressing force. As a result, even if the external insulating sealing material 320 is thermally expanded, the external insulating sealing material 320 can be kept within a predetermined range, so that the sealing performance in the vicinity of the electrode terminal 330 can be sufficiently maintained. . In other words, since the electricity storage element 300 according to Embodiment 2 further has the effect of the convex portion 325 formed on the external insulating sealing material 320, the sealing performance in the vicinity of the electrode terminal 330 can be sufficiently improved.

  In addition, according to power storage element 300 according to the present embodiment, external insulating sealing material 320 is disposed between terminal body 331 and lid portion 311 of container 310. Further, the external insulating sealing material 320 is disposed between the connection portion 332 and the lid portion 311 of the container 310. That is, the external insulating sealing material 320 is filled between the electrode terminal 330 (the terminal main body 331 and the connecting portion 332) and the lid portion 311 of the container 310 without a gap. For this reason, the sealing performance in the vicinity of the electrode terminal 330 can be improved. Further, since the external insulating sealing material 320 is filled between the electrode terminal 330 and the lid portion 311 of the container 310 without any gap, it easily expands in a direction intersecting with the direction of the pressing force when thermally expanded. However, the space in which the external insulating sealing material 320 is arranged is such that the terminal body 331 and the lid portion 311 of the container 310 become farther away from the terminal body 331 and the connection part 332 of the electrode terminal 330 in the direction intersecting the direction of the pressing force. And the interval between the connection portion 332 and the lid portion 311 of the container 310 are narrowed, so that the external insulating sealing material 320 can be prevented from expanding in the direction intersecting the direction of the pressing force.

  Moreover, according to the electrical storage element 300 according to the present embodiment, the terminal main body 331 and the lid of the container 310 are moved away from the connection portion 332 between the first position P1 and the second position P2. It is formed so that the distance from 311 is small. For this reason, during the thermal expansion of the external insulating sealing material 320, when the external insulating sealing material 320 expands in the direction intersecting the direction of the pressing force, it is between the first position P1 and the second position P2. The force applied to the external insulating sealing material 320 can be dispersed. Specifically, this force is a force that prevents the outer insulating sealing material 320 from expanding in a direction farther than the connection portion 332, and is a force directed in a direction closer to the connection portion 332. . As a result, the terminal body 331, the lid 311 of the container 310, or the external insulating sealing material 320 can be identified as compared with a structure in which the distance between the terminal body 331 and the lid 311 of the container 310 is rapidly reduced. Thus, it is possible to prevent a large force from being applied to the part, and it is possible to prevent the terminal main body 331, the lid portion 311 of the container 310, or the external insulating sealing material 320 from being damaged.

  Further, according to power storage device 300 according to the present exemplary embodiment, surface 331a on the cover 311 side of container 310 of terminal body 331 is linear with respect to surface 311a on the side of terminal body 331 of cover 311 of container 310. It is inclined to. For this reason, during the thermal expansion of the external insulating sealing material 320, when the external insulating sealing material 320 expands with respect to the direction intersecting the direction of the pressing force, between the first position P1 and the second position P2. With respect to the external insulating sealing material 320, the force directed in the direction close to the connection portion 332 can be made uniform at least between the first position P1 and the second position P2. Thus, between the first position P1 and the second position P2, the force applied to the terminal main body 331, the lid 311 of the container 310, or the external insulating sealing material 120 can be equalized. The applied force can be minimized. For this reason, it can prevent more effectively that the terminal main body 331, the cover part 311 of the container 310, or the external insulation sealing material 320 is damaged.

  Moreover, according to the electricity storage element 300 according to the present embodiment, the shape of the lid portion 311 of the container 310 is such that the third distance d3 between the connection portion 332 and the lid portion 311 of the container 310 is the third position P3. It is smaller than the fourth distance d4 between the connecting portion 332 and the lid portion 311 of the container 310 at the fourth position P4 on the outer side of the lid portion 311 of the container 310 than the position P3. The external insulating sealing material 320 is sandwiched between the connecting portion 332 and the lid portion 311 of the container 310, and when thermally expanded, the external insulating sealing material 320 tends to expand in a direction crossing the direction of the pressing force. . At this time, since the third interval d3 at the third position P3 that is the position on the inner side of the lid 311 of the container 310 is narrower than the fourth interval d4, even if the external insulating sealing material 320 is thermally expanded, It is possible to suppress the external insulating sealing material 320 from expanding toward the inner side of the lid 311 of the container 310. As a result, when the external insulating sealing material 320 is thermally expanded, the external insulating sealing material 320 can be retained within a predetermined range in the axial direction of the connection portion 332. Sex can be sufficiently maintained.

  Moreover, according to the electrical storage element 300 according to the present embodiment, the lid 311 of the container 310 is moved away from the terminal body 331 between the third position P3 and the fourth position P4. The distance from the lid 311 is reduced. For this reason, during the thermal expansion of the external insulating sealing material 320, when the external insulating sealing material 320 expands in the direction intersecting the direction of the pressing force, it is between the third position P3 and the fourth position P4. The force applied to the external insulating sealing material 320 can be dispersed. Specifically, this force is a force that prevents the outer insulating sealing material 320 from expanding toward the inside of the container 310 and is a force directed toward the terminal body 331. As a result, the terminal body 331, the lid 311 of the container 310, or the external insulating sealing material 320 can be identified as compared with a structure in which the distance between the connection portion 332 and the lid 311 of the container 310 is rapidly reduced. Thus, it is possible to prevent a large force from being applied to the part, and it is possible to prevent the terminal main body 331, the lid portion 311 of the container 310, or the external insulating sealing material 320 from being damaged.

  In addition, according to power storage device 300 according to the present exemplary embodiment, surface 311b of connecting portion 332 side of lid portion 311 of container 310 is linearly inclined with respect to surface 332a of connecting portion 332. For this reason, during the thermal expansion of the external insulating sealing material 320, when the external insulating sealing material 320 expands in the direction intersecting the direction of the pressing force, it is between the third position P3 and the fourth position P4. With respect to the external insulating sealing material 320, the force directed in the direction close to the connection portion 332 can be made uniform at least between the third position P3 and the fourth position P4. Thus, between the third position P3 and the fourth position P4, the force applied to the terminal main body 331, the lid 311 of the container 310, or the external insulating sealing material 320 can be made uniform. The applied force can be minimized. For this reason, it can prevent that the terminal main body 331, the cover part 311 of the container 310, or the external insulation sealing material 320 is damaged.

  Moreover, according to the electrical storage element 300 according to the present embodiment, the external insulating sealing material 320 and the lid portion 311 of the container 310 are pressure-bonded by the electrode terminal 330 so that the through hole 313 of the lid portion 311 of the container 310 is formed. The portion to be formed and the terminal body 331 are sealed with an external insulating sealing material 320. For this reason, the external insulating sealing material 320 is in a state in which a pressing force is always applied between the terminal body 331 and the lid 311 of the container 310 by the electrode terminal 330. Even in the case of the external insulating sealing material 320 in such a state that the pressing force is always applied and it is easy to expand in the direction crossing the pressing force when thermally expanded, the space in the direction crossing the pressing force Therefore, the expansion of the external insulating sealing material 320 in the direction can be suppressed.

(Modification)
(1)
According to the electricity storage device 300 according to the second embodiment, the terminal main body 331 is configured such that the surface 331a on the lid 311 side of the container 310 of the terminal main body 331 is the container 310 between the first position P1 and the second position P2. Although it inclines linearly with respect to the surface 311a on the terminal body 331 side of the lid 311, it is not limited to inclining linearly. For example, the terminal body may be formed such that the first interval in the first region including the first position and the second interval in the second region including the second position are stepwise different. Moreover, you may form a terminal main body so that the space | interval of a terminal main body and the cover part of a container may become small gradually. In other words, the terminal body only needs to monotonously decrease as the distance between the terminal body and the lid portion of the container moves from the second position to the first position.

(2)
In addition, according to the electricity storage device 300 according to the second embodiment, the lid 311 of the container 310 is connected to the connecting portion 332 and the container at the third position P3 of the lid 311 of the container 310 at a portion facing the connecting portion 332. The third distance d3 between the lid 311 of 310 and the fourth position P4 between the connecting portion 332 and the lid 311 of the container 310 at the fourth position P4 located on the outer side of the lid 311 of the container 310 relative to the third position P3. Although it is formed to be smaller than the interval d4, it is not limited to this. That is, the third interval between the connection portion at the third position and the lid portion of the container, and the fourth distance between the connection portion at the fourth position and the lid portion of the container at the outer side of the lid portion of the container from the third position. The shape may be equal to the interval. In short, the through-hole formed in the lid portion of the container may be formed so as to have the same diameter regardless of whether it is an inner position or an outer position of the container.

(3)
Moreover, according to the electrical storage element 300 according to the above-described embodiment and each of the above-described modifications, the shape (specifically, the thickness) of the terminal body 331 is different between the first position P1 and the second position P2. Thus, the first interval d1 and the second interval d2 are formed to be different from each other. However, the present invention is not limited to this. For example, it is good also as a shape which the shape of the cover part of a container approaches a terminal main body as it goes to a 1st position from a 2nd position.

  INDUSTRIAL APPLICABILITY The present invention is useful as a power storage element that can improve the sealing performance in the vicinity of the electrode terminal of the power storage element.

100, 300 Electric storage element 110, 310 Container 111, 311 Lid 112 Container body 113, 313 Through hole 114 Opening 120, 220, 320 External insulation sealing material 121, 221, 321 Plate member 122 Frame body 123 Tube part 124 Through hole 125, 225, 325 Protruding part 125a Groove part 130, 330 Electrode terminal 131, 331 Terminal body 132, 332 Connection part 133 Caulking end 150 Internal insulation sealing material 151 Through hole 160, 164 Current collecting member 161 Plate part 162 Through hole 163 Arm 170 Electrode 171, 172 Projection 180 Sealant 225 a Projection 311 a Surface 311 b Surface 321 a Surface 331 a Surface 332 a Surface

Claims (11)

A container, an electrode body housed in the container, an electrode terminal, a current collecting member that electrically connects the electrode terminal and the electrode body, and an insulating member that insulates the container from the electrode terminal; A storage element comprising:
The electrode terminal penetrates the container and is connected to the current collector, a columnar connection part, and a plate-like terminal body that is an end of the connection part and is disposed outside the container. Have
The insulating member has a plate-like member disposed between the container and the terminal body,
The power storage device further includes a sealing agent provided between at least one of the terminal body and the container and the insulating member,
The plate-like member is provided in an annular shape surrounding the connecting portion, and has a convex portion protruding in a direction intersecting the plate-like member,
The convex portion has a holding portion capable of holding a liquid at a tip thereof. The power storage element according to claim 1, wherein the holding portion is a groove portion formed along the annular direction of the convex portion at the tip of the convex portion. The electric storage element according to claim 1, wherein the holding part is a plurality of protrusions that are continuously formed along an annular direction of the convex part. At least one of the terminal main body and the container has the terminal main body in a second position where the first distance between the terminal main body and the container in the first position of the terminal main body is closer to the connecting portion than the first position. The electric storage element according to claim 1, wherein the electric storage element is formed to be smaller than a second distance between the container and the container. The electrical storage according to claim 4, wherein at least one of the terminal body and the container is formed such that a distance between the terminal body and the container is reduced from the second position toward the first position. element. In at least one of the terminal body and the container, the container side surface of the terminal body is linear with respect to the terminal body side surface of the container between the first position and the second position. The electrical storage element according to claim 5, wherein The at least one of the terminal main body and the container has a stepwise difference between the first interval in the first region including the first position and the second interval in the second region including the second position. The electrical storage element as described in. The container has a fourth position where a third distance between the connection portion and the container at a third position of the container is located on an outer side of the container with respect to the third position at a portion facing the connection portion. The power storage element according to claim 1, wherein the power storage element is formed to be smaller than a fourth distance between the connection portion and the container. The electric storage element according to claim 8, wherein the container is formed such that a distance between the connection portion and the container becomes smaller from the fourth position toward the third position. The surface of the container that faces the connection portion of the container is inclined linearly with respect to the surface of the connection portion between the third position and the fourth position. The electrical storage element as described in. The said electrode terminal seals between the part in which the through-hole of the said container is formed, and the said terminal main body by the said insulating member by crimping | bonding the said insulating member and the said container. The electrical storage element of 1 item | term.

Images