阅读说明：本技术 蓄电元件 (Electric storage element ) 是由 团野浩之 中西顺 于 2018-07-13 设计创作，主要内容包括：一种具备容器(100)的蓄电元件(10),其中,容器(100)具有：盖体(110),其形成有电解液的注液口(111)；以及注液栓(400),其堵塞注液口(111),注液栓(400)具有：轴部(410),其插入注液口(111)；以及突出部(420),其从轴部(410)的外周突出而与盖体(110)接合,在盖体(110)上,在注液口(111)的周围形成有与轴部(410)相邻的空间(113),轴部(410)的前端配置于注液口(111)内。(An electric storage element (10) provided with a container (100), wherein the container (100) has: a lid (110) having a liquid inlet (111) for the electrolyte; and a filling plug (400) that closes the filling opening (111), the filling plug (400) having: a shaft part (410) which is inserted into the liquid inlet (111); and a protrusion part (420) that protrudes from the outer periphery of the shaft part (410) and is joined to the lid body (110), wherein a space (113) adjacent to the shaft part (410) is formed around the liquid injection port (111) in the lid body (110), and the tip of the shaft part (410) is disposed in the liquid injection port (111).)

1. An electric storage element comprising a container, wherein,

the container has:

a wall portion having an electrolyte injection port; and

a liquid injection plug which blocks the liquid injection port,

the liquid injection plug comprises: a shaft portion inserted into the liquid inlet; and a protruding portion that protrudes from an outer periphery of the shaft portion to be engaged with the wall portion,

a space adjacent to the shaft portion is formed around the liquid inlet in the wall portion,

the front end of the shaft portion is disposed in the liquid inlet.

2. The power storage element according to claim 1,

the distance between the tip of the shaft portion and the inner surface of the wall portion in the axial direction of the shaft portion is longer than the length of the portion of the shaft portion that abuts the inner circumferential surface of the liquid inlet.

3. The power storage element according to claim 1 or 2, wherein,

the length of the portion of the shaft portion in contact with the inner peripheral surface of the liquid inlet is smaller than the length of the boundary portion between the shaft portion and the space in the axial direction of the shaft portion.

4. The power storage element according to any one of claims 1 to 3,

the wall portion has an inclined surface which is disposed adjacent to the space and is inclined toward the inside of the container as it goes toward the pouring port.

5. The power storage element according to any one of claims 1 to 4,

the portion of the shaft portion adjacent to the space has the same diameter as the portion of the shaft portion that abuts against the inner peripheral surface of the liquid inlet, or a smaller diameter than the portion of the shaft portion that abuts against the inner peripheral surface of the liquid inlet.

6. An electric storage element comprising a container, wherein,

the container has:

a wall portion having an electrolyte injection port; and

a liquid injection plug which blocks the liquid injection port,

the liquid injection plug comprises: a cylindrical shaft portion extending in a first direction and inserted into the liquid inlet; and a protruding portion that protrudes from an outer periphery of the shaft portion in a second direction orthogonal to the first direction in cross section and engages with an outer surface of the wall portion,

the shaft portion and the protruding portion are integrally formed as one piece from a metal member,

a recess recessed from the outer surface is formed in the wall portion around the liquid pouring port, and a space is formed by the shaft portion, the protruding portion, and the recess,

the shaft portion has a cylindrical portion having the same diameter from the protruding portion to an inlet of the liquid inlet.

Technical Field

The present invention relates to an electric storage element including a container having a wall portion formed with a liquid injection port, and a liquid injection plug for closing the liquid injection port.

Background

Conventionally, an electric storage element including a container having a wall portion formed with a liquid injection port and a liquid injection plug for closing the liquid injection port is widely known. For example, patent document 1 discloses a sealed battery (power storage element) including a container having: a sealing plate (wall portion) having a liquid injection hole (liquid injection port); and a sealing plug (liquid filling plug) for sealing the liquid filling hole. In this sealed battery, the sealing plug has a press-in member that presses in the pouring hole to seal the pouring hole, and the sealing performance of the pouring hole is maintained for a long period of time.

Prior art documents

Patent document

Patent document 1: japanese patent laid-open publication No. 2014-170648

Disclosure of Invention

Problems to be solved by the invention

Here, in the conventional power storage element, a portion of the pouring plug inserted into the pouring port is generally disposed so as to protrude inward from the pouring port. For example, in patent document 1, in order to reliably close the pouring hole with the press-fitting member of the sealing plug, the press-fitting member is press-fitted into the pouring hole until the tip end protrudes from the pouring hole. However, in this case, there are problems as follows: the electrolyte in the container rises from the pouring port along the portion of the pouring plug inserted into the pouring port, such as the press-fitting member. When the electrolyte rises from the injection port when the injection plug is welded to the wall portion of the container, for example, a poor joint between the injection plug and the wall portion of the container may occur due to the electrolyte.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an electric storage device capable of suppressing a failure in joining a filling plug to a wall portion of a container.

Means for solving the problems

In order to achieve the above object, an electric storage device according to an aspect of the present invention includes a container, wherein the container includes: a wall portion having an electrolyte injection port; and a liquid injection plug that blocks the liquid injection port, the liquid injection plug having: a shaft portion inserted into the liquid inlet; and a protruding portion that protrudes from an outer periphery of the shaft portion and is joined to the wall portion, wherein a space adjacent to the shaft portion is formed around the liquid inlet in the wall portion, and a tip end of the shaft portion is disposed in the liquid inlet.

A power storage element according to another aspect of the present invention includes a container, wherein the container includes: a wall portion having an electrolyte injection port; and a liquid injection plug that blocks the liquid injection port, the liquid injection plug having: a cylindrical shaft portion extending in a first direction and inserted into the liquid inlet; and a protrusion portion that protrudes from an outer periphery of the shaft portion in a second direction orthogonal to the first direction in cross section and is joined to an outer surface of the wall portion, wherein the shaft portion and the protrusion portion are integrally formed as one piece by a metal member, a recess portion that is recessed from the outer surface is formed in the wall portion around the liquid injection port, a space is formed by the shaft portion, the protrusion portion, and the recess portion, and the shaft portion has a cylindrical portion having the same diameter from the protrusion portion to an inlet of the liquid injection port.

Effects of the invention

According to the power storage element of the present invention, poor engagement between the injection plug and the wall portion of the container can be suppressed.

Drawings

Fig. 1 is a perspective view showing an external appearance of an electric storage device according to an embodiment.

Fig. 2 is a perspective view illustrating each component provided in the power storage element according to the embodiment.

FIG. 3 is a perspective view showing the structure of the lid body around the pouring outlet and the structure of the pouring stopper according to the embodiment.

FIG. 4 is a sectional view showing the structure of the lid body around the pouring port and the structure of the pouring stopper in the embodiment.

FIG. 5 is a sectional view showing the structure of the lid body of modification 1 of the embodiment around the pouring port and the structure of the pouring stopper.

FIG. 6 is a cross-sectional view showing the structure of the lid body in the vicinity of the pouring port and the structure of the pouring stopper in modification 2 of the embodiment.

FIG. 7 is a sectional view showing the structure of the lid body of modification 3 of the embodiment around the pouring outlet and the structure of the pouring stopper.

FIG. 8 is a sectional view showing the structure of the lid body of modification 4 of the embodiment around the pouring outlet and the structure of the pouring stopper.

FIG. 9 is a sectional view showing the structure of the lid body of modification 5 of the embodiment around the pouring outlet and the structure of the pouring stopper.

Detailed Description

The invention aims to provide an electric storage element capable of suppressing poor joint between a filling plug and a wall part of a container.

In order to achieve the above object, an electric storage device according to an aspect of the present invention includes a container, wherein the container includes: a wall portion having an electrolyte injection port; and a liquid injection plug that blocks the liquid injection port, the liquid injection plug having: a shaft portion inserted into the liquid inlet; and a protruding portion that protrudes from an outer periphery of the shaft portion and is joined to the wall portion, wherein a space adjacent to the shaft portion is formed around the liquid inlet in the wall portion, and a tip end of the shaft portion is disposed in the liquid inlet.

In this way, in the electric storage element, a space adjacent to the shaft portion of the filling plug is formed around the filling port in the wall portion of the container, and the tip end of the shaft portion of the filling plug is disposed in the filling port. In other words, when the electrolyte adheres to the shaft portion of the liquid injection plug, the electrolyte enters between the shaft portion and the inner peripheral surface of the liquid injection port and ascends, but the larger the contact area between the shaft portion and the inner peripheral surface of the liquid injection port, the larger the amount of the electrolyte that enters and ascends. Therefore, a space adjacent to the shaft portion of the liquid pouring plug is formed around the liquid pouring port, and the tip of the shaft portion of the liquid pouring plug is disposed in the liquid pouring port, so that the contact area between the shaft portion and the inner peripheral surface of the liquid pouring port is reduced, and the amount of the electrolyte that enters between the shaft portion and the inner peripheral surface of the liquid pouring port and ascends is reduced. Further, when the distal end of the shaft portion of the liquid pouring stopper is disposed in the liquid pouring port, the distal end of the shaft portion functions as a cover, and the electrolyte solution adhering to the lower side than the distal end of the shaft portion of the liquid pouring stopper in the liquid pouring port can be prevented from entering between the shaft portion and the inner peripheral surface of the liquid pouring port. This can suppress the electrolyte from rising from the electrolyte injection port. Further, by forming a space adjacent to the shaft portion of the pouring stopper around the pouring port, the electrolyte can be stored in the space, and thus the electrolyte can be further prevented from rising from the pouring port. Accordingly, poor engagement between the filling stopper and the wall portion of the container can be suppressed.

Further, the distance between the tip of the shaft portion and the inner surface of the wall portion may be larger than the length of the portion of the shaft portion that abuts the inner peripheral surface of the liquid inlet in the axial direction of the shaft portion.

Thus, in the electric storage element, the distance between the tip of the shaft portion of the liquid injection plug and the inner surface of the wall portion of the container in the axial direction of the shaft portion is greater than the length of the portion of the shaft portion in contact with the inner circumferential surface of the liquid injection port. In this way, the distance between the tip of the shaft portion and the inner surface of the wall portion is increased, and the length of the portion of the shaft portion in contact with the inner peripheral surface of the liquid inlet is decreased, whereby the contact area between the shaft portion and the inner peripheral surface of the liquid inlet is decreased, and the amount of the electrolyte solution that enters between the shaft portion and the inner peripheral surface of the liquid inlet is decreased. This can further suppress the rising of the electrolyte solution from the liquid inlet.

In addition, the length of the portion of the shaft portion in contact with the inner peripheral surface of the liquid inlet may be smaller than the length of the boundary portion between the shaft portion and the space in the axial direction of the shaft portion.

Thus, in the electric storage element, the length of the portion of the shaft portion of the liquid injection plug that contacts the inner peripheral surface of the liquid injection port in the axial direction is smaller than the length of the boundary portion between the shaft portion and the space. In this way, by reducing the length of the portion of the shaft portion in contact with the inner peripheral surface of the liquid inlet and increasing the length of the boundary portion between the shaft portion and the space, the area of contact between the shaft portion and the inner peripheral surface of the liquid inlet can be reduced, and the liquid pool of the electrolyte can be increased. This can further suppress the rising of the electrolyte solution from the liquid inlet.

The wall portion may have an inclined surface that is disposed adjacent to the space and is inclined toward the inside of the container toward the pouring port.

Thus, in the power storage element, the wall portion of the container has the inclined surface inclined toward the inside of the container as it goes toward the liquid inlet, and therefore the inclined surface can suppress the rising of the electrolyte. This can further suppress the rising of the electrolyte solution from the liquid inlet.

Further, a portion of the shaft portion adjacent to the space may have the same diameter as a portion of the shaft portion that abuts against the inner circumferential surface of the liquid inlet, or a diameter smaller than a portion of the shaft portion that abuts against the inner circumferential surface of the liquid inlet.

When the liquid pouring port is formed in the wall portion, a burr may be generated which protrudes upward from the vicinity of the inlet of the liquid pouring port toward the space. In this case, if the diameter of the portion of the shaft portion adjacent to the space is larger than the diameter of the portion of the shaft portion abutting against the inner peripheral surface of the liquid pouring port, the large diameter portion interferes with the burr to lift the liquid pouring plug. The stopper is tilted, and therefore, there is a possibility that the protruding portion of the stopper is not properly engaged with the wall portion of the container. Therefore, by setting the portion of the shaft portion adjacent to the space to the same diameter as or smaller than the portion of the shaft portion in contact with the inner peripheral surface of the pouring port, it is possible to suppress the burr from interfering with the shaft portion and lifting the filling stopper, and to suppress a defective joint between the filling stopper and the wall portion of the container.

In addition, an electricity storage element according to another aspect of the present invention includes a container having a wall portion in which a pouring port for an electrolytic solution is formed; and a liquid injection plug that blocks the liquid injection port, the liquid injection plug having: a cylindrical shaft portion extending in a first direction and inserted into the liquid inlet; and a protrusion portion that protrudes from an outer periphery of the shaft portion in a second direction orthogonal to the first direction in cross section and is joined to an outer surface of the wall portion, wherein the shaft portion and the protrusion portion are integrally formed as one piece by a metal member, a recess portion that is recessed from the outer surface is formed in the wall portion around the liquid injection port, a space is formed by the shaft portion, the protrusion portion, and the recess portion, and the shaft portion has a cylindrical portion having the same diameter from the protrusion portion to an inlet of the liquid injection port.

When the electrolyte adheres to the shaft portion of the liquid injection plug, the electrolyte enters between the shaft portion and the inner peripheral surface of the liquid injection port and ascends, but the larger the contact area between the shaft portion and the inner peripheral surface of the liquid injection port, the larger the amount of the electrolyte that enters and ascends. Therefore, a space adjacent to the shaft portion of the liquid pouring stopper is formed, and the shaft portion of the liquid pouring stopper is disposed in the liquid pouring port, so that the contact area between the shaft portion and the inner peripheral surface of the liquid pouring port is reduced, and the amount of the electrolyte that enters between the shaft portion and the inner peripheral surface of the liquid pouring port and ascends is reduced. Further, when the shaft portion of the liquid pouring stopper is disposed in the liquid pouring port, the distal end of the shaft portion functions as a cover, and the electrolyte solution adhering to the lower side than the distal end of the shaft portion of the liquid pouring stopper in the liquid pouring port can be prevented from entering between the shaft portion and the inner peripheral surface of the liquid pouring port. This can suppress the electrolyte from rising from the electrolyte injection port. Further, by forming a space adjacent to the shaft portion of the pouring stopper around the pouring port, the electrolyte can be stored in the space, and thus the electrolyte can be further prevented from rising from the pouring port. In addition, when the shaft portion of the liquid injection plug and the protruding portion that engages with the wall portion are formed as separate members, it is necessary to increase the diameter of the portion of the shaft portion adjacent to the space so that the shaft portion does not fall from the liquid injection port into the electric storage element. However, if the diameter of the portion of the shaft portion adjacent to the space is increased, if there is a burr protruding from the vicinity of the inlet of the liquid inlet toward the space and upward, the large-diameter portion interferes with the burr, and the shaft portion is lifted from the liquid inlet. If the shaft portion is lifted from the liquid inlet, the electrolyte solution rising from the liquid inlet cannot be suppressed, and there is a possibility that a poor joint between the liquid filling plug and the wall portion of the container may occur due to the electrolyte solution. Therefore, the shaft portion of the filling stopper and the protruding portion are integrally formed as one piece by the metal member, so that the shaft portion can be prevented from falling from the filling opening into the electric storage element, and the shaft portion is formed into a cylindrical shape having the same diameter as the entrance from the protruding portion to the filling opening, so that the filling stopper can be prevented from being lifted up due to interference of the shaft portion with burrs, and a poor joint between the filling stopper and the wall portion of the container can be suppressed.

The present invention can be realized not only as an electric storage device but also as a container having a wall portion and a liquid injection plug provided in the electric storage device.

Hereinafter, an electric storage device according to an embodiment of the present invention and a modification thereof will be described with reference to the drawings. The embodiments and modifications described below are all general or specific examples. The numerical values, shapes, materials, constituent elements, arrangement positions of constituent elements, connection modes, and the like shown in the following embodiments and modifications thereof are examples, and are not intended to limit the present invention. Among the components of the following embodiments and modifications thereof, components not described in an independent claim showing the highest concept will be described as arbitrary components. In the drawings, the dimensions and the like are not strictly illustrated.

In the following description of the embodiments and the drawings, the direction in which a pair of electrode terminals of an electric storage element are arranged, the direction in which a pair of collectors are arranged, the direction in which both ends of an electrode assembly (a pair of active material layer non-forming portions) are arranged, the axial direction in which the electrode assembly is wound, the width direction of the leg portions of the collectors, or the facing direction of the short side surfaces of a container are defined as the X-axis direction. The opposing direction of the long side surfaces of the container, the short side direction of the short side surfaces of the container, or the thickness direction of the container is defined as the Y-axis direction. The Z-axis direction is defined as the direction in which the container body and the lid of the storage element are aligned, the longitudinal direction of the short side surface of the container, the direction in which the leg of the current collector extends, or the vertical direction. The X-axis direction, the Y-axis direction, and the Z-axis direction are directions intersecting with each other (orthogonal in the present embodiment). In the following description, the Z-axis direction is described as the vertical direction for convenience of description, although the case where the Z-axis direction is not the vertical direction is also considered according to the usage. In the following description, for example, the X-axis direction positive side indicates the X-axis arrow direction side, and the X-axis direction negative side indicates the side opposite to the X-axis direction positive side. The same applies to the Y-axis direction and the Z-axis direction.

(embodiment mode)

[1 ] explanation of the entirety of the storage element 10 ]

First, the entire power storage element 10 of the present embodiment will be described with reference to fig. 1 and 2. Fig. 1 is a perspective view showing an external appearance of an electric storage device 10 according to the present embodiment. Fig. 2 is a perspective view showing each component included in the power storage element 10 according to the present embodiment. Specifically, fig. 2 is a perspective view showing the structure of the power storage device 10 in a state in which the container body 120 and the liquid filling stopper 400 are separated.

The storage element 10 is a rechargeable battery that can be charged and discharged, and specifically is a nonaqueous electrolyte secondary battery such as a lithium ion secondary battery. The power storage element 10 is used for, for example, a power supply for a vehicle such as an Electric Vehicle (EV), a Hybrid Electric Vehicle (HEV), or a plug-in hybrid electric vehicle (PHEV), a power supply for an electronic device, a power supply for electric power storage, and the like. The power storage element 10 is not limited to the nonaqueous electrolyte secondary battery, and may be a secondary battery other than the nonaqueous electrolyte secondary battery, a capacitor, or a primary battery that can use stored electric power even when a user is not charged. In the present embodiment, the rectangular (square) energy storage element 10 is illustrated, but the shape of the energy storage element 10 is not limited to the rectangular shape, and may be a cylindrical shape, a long cylindrical shape, or the like, or may be a stacked type energy storage element.

As shown in fig. 1, the power storage element 10 includes: a container 100 having a lid 110 and a container body 120; a positive electrode terminal 200; and a negative terminal 300. As shown in fig. 2, the electrode body 130, the positive electrode collector 140, and the negative electrode collector 150 are housed inside the container 100.

Gaskets and the like are disposed between the lid 110 and the positive electrode terminal 200 and between the lid 110 and the positive electrode current collector 140 to improve insulation and airtightness, but are not illustrated in the drawing. The same applies to the negative electrode side. Although an electrolyte (nonaqueous electrolyte) is sealed inside the container 100, illustration thereof is omitted. The type of the electrolyte is not particularly limited as long as the electrolyte does not impair the performance of the power storage element 10, and various electrolytes can be selected. In addition to the above-described components, a separator disposed on the side of the positive electrode collector 140 and the negative electrode collector 150, a gas discharge valve for releasing the pressure when the pressure in the container 100 rises, an insulating film for enclosing the electrode body 130, and the like may be disposed.

The container 100 is a rectangular parallelepiped (box-shaped) outer case, and includes a container body 120 having a rectangular cylindrical shape and a bottom, and a lid body 110 as a plate-shaped member for closing an opening of the container body 120. Specifically, the lid 110 is a flat plate-like and rectangular wall portion extending in the X-axis direction, and is disposed on the Z-axis direction positive side of the container body 120. The container body 120 includes 5 wall portions, i.e., a flat-plate-shaped rectangular bottom wall portion on the Z-axis direction negative side, a flat-plate-shaped rectangular long side wall portion on the Y-axis direction side surfaces, and a flat-plate-shaped rectangular short side wall portion on the X-axis direction side surfaces. The container 100 is a member capable of sealing the inside by, for example, welding the lid 110 to the container main body 120 after the electrode body 130 and the like are housed inside the container main body 120. The material of the lid 110 and the container body 120 is not particularly limited, but is preferably a weldable metal such as stainless steel, aluminum alloy, iron, and plated steel sheet.

As shown in fig. 2, the lid 110 is provided with an electrolyte solution inlet 111. The liquid inlet 111 is a circular through hole formed in the lid 110 for injecting the electrolyte during the production of the power storage element 10. In the present embodiment, the liquid inlet 111 is disposed on the X-axis direction negative side and the Y-axis direction negative side of the lid 110. The pouring outlet 111 may be disposed at any position of the lid 110.

As shown in fig. 1 and 2, a pouring stopper 400 that blocks the pouring outlet 111 is disposed on the lid body 110. In other words, during the production of the electricity storage element 10, the electrolyte is injected into the container 100 through the injection port 111, and the injection plug 400 is welded to the lid body 110 or the like to close the injection port 111, whereby the electrolyte is contained in the container 100. In this way, the container 100 includes the lid 110, which is a wall portion in which the electrolyte solution pouring port 111 is formed, and the pouring stopper 400 that closes the pouring port 111. The structure of the lid body 110 around the pouring outlet 111 and the structure of the pouring stopper 400 will be described in detail later.

The electrode body 130 is an electric storage element (electric power generation element) that includes a positive electrode plate, a negative electrode plate, and a separator and is capable of storing electric power. The positive electrode plate is a plate in which a positive electrode active material layer is formed on a positive electrode base material layer which is a long strip-shaped current collecting foil made of aluminum, aluminum alloy, or the like. The negative electrode plate is formed by forming a negative electrode active material layer on a negative electrode base material layer which is a long strip-shaped current collecting foil made of copper, copper alloy, or the like. The separator is a microporous sheet made of resin or the like. The electrode body 130 is formed by disposing and winding a separator between the positive electrode plate and the negative electrode plate. In the present embodiment, an oval shape is illustrated as the cross-sectional shape of the electrode body 130, but an oval shape, a circular shape, a polygonal shape, or the like may be used. The shape of the electrode assembly 130 is not limited to a wound type, and may be a laminated type in which flat plate-like electrode plates are laminated.

The positive electrode terminal 200 is an electrode terminal electrically connected to the positive electrode plate of the electrode body 130, and the negative electrode terminal 300 is an electrode terminal electrically connected to the negative electrode plate of the electrode body 130. In other words, the positive electrode terminal 200 and the negative electrode terminal 300 are metal electrode terminals for leading out the electric power stored in the electrode body 130 to the outside space of the electric storage device 10 or for leading in the electric power to the inside space of the electric storage device 10 in order to store the electric power in the electrode body 130. The positive electrode terminal 200 and the negative electrode terminal 300 are attached to the lid 110 disposed above the electrode assembly 130.

The positive electrode current collector 140 and the negative electrode current collector 150 are the following members: is disposed between the electrode body 130 and the wall surface of the container 100, and has conductivity and rigidity for electrically connecting the positive electrode terminal 200 and the negative electrode terminal 300 to the positive electrode plate and the negative electrode plate of the electrode body 130. The material of the positive electrode collector 140 is not limited, but is formed of, for example, aluminum or an aluminum alloy, as in the positive electrode base material layer of the electrode assembly 130. The material of the negative electrode current collector 150 is not limited, but it is formed of copper, a copper alloy, or the like, for example, as in the negative electrode base material layer of the electrode assembly 130.

[2 description of the structure of the pouring spout 400 and the periphery of the pouring port 111 of the lid body 110 ]

Next, the structure of the lid body 110 around the pouring outlet 111 and the structure of the pouring stopper 400 will be described in detail. FIG. 3 is a perspective view showing the structure of the lid body 110 around the pouring outlet 111 and the structure of the pouring stopper 400 according to the present embodiment. Specifically, fig. 3 is an enlarged perspective view of the periphery of the pouring outlet 111 of the lid body 110 and the structure of the pouring stopper 400 in fig. 2. Fig. 4 is a cross-sectional view showing the structure around the pouring outlet 111 of the lid body 110 and the structure of the pouring stopper 400 according to the present embodiment. Specifically, fig. 4 is an enlarged sectional view of the cap 110 and the filling stopper 400 shown in fig. 1, taken along the IV-IV section.

[2.1 description of the structure of the liquid filling stopper 400 ]

First, the structure of the injection stopper 400 will be described in detail. The pouring stopper 400 is a member joined to the lid body 110 by welding or the like in a state where the pouring outlet 111 is closed. The material of the liquid filling plug 400 is not particularly limited, but is formed of a metal that can be welded to the lid body 110, such as stainless steel, aluminum alloy, iron, or plated steel plate. As shown in fig. 3 and 4, the injection plug 400 includes a shaft portion 410 and a protrusion portion 420.

The shaft portion 410 is a columnar portion that extends in the Z-axis direction (first direction) and is inserted into the pouring outlet 111. Specifically, as shown in fig. 4, the shaft portion 410 includes a pillar portion 412 having a concave portion 411 formed on an upper surface thereof, a reduced diameter portion 413 gradually reduced in diameter from the pillar portion 412 toward the Z-axis direction negative side, and a tip portion 414 extending from the reduced diameter portion 413 toward the Z-axis direction negative side.

The pillar portion 412 is a columnar portion on the positive side in the Z-axis direction of the shaft portion 410, and a conical recess 411 recessed toward the negative side in the Z-axis direction is formed on the surface on the positive side in the Z-axis direction of the pillar portion 412. The concave portion 411 is used as a mark for joining the filling stopper 400 to the outer surface 114 of the cover body 110, for example. In other words, the position of the injection stopper 400 can be grasped by the recess 411, and therefore the injection stopper 400 can be placed at a correct position on the outer surface 114 and joined to the outer surface 114. The reduced diameter portion 413 is as follows: in the cross-sectional shape cut by the YZ plane, the outer edge shape is formed by a curved line such that the width in the Y-axis direction gradually decreases from the end portion of the pillar portion 412 on the Z-axis direction negative side toward the Z-axis direction negative side. The distal end portion 414 is a cylindrical portion extending from the end portion on the Z-axis direction negative side of the reduced diameter portion 413 toward the Z-axis direction negative side. In other words, the tip portion 414 is the tip portion on the Z-axis direction negative side of the shaft portion 410.

The protruding portion 420 protrudes from the outer periphery of the shaft portion 410 in a second direction orthogonal to the Z-axis direction (first direction) in cross-section and is joined to the lid body 110. Specifically, the protruding portion 420 is a flat plate-like portion (flange portion) that protrudes outward from the entire periphery of the upper end portion of the shaft portion 410 (in other words, the upper portion of the column portion 412) and is annular (ring-shaped) in plan view. In addition, the planar view means a case of being viewed from the Z-axis direction positive side, and for example, the annular shape in the planar view means a shape having an annular shape when viewed from the Z-axis direction positive side.

The projection 420 is placed on the outer surface 114 with the inner surface (surface on the Z-axis direction negative side) in contact with the outer surface 114 of the lid body 110, and the outer edge portion is joined to the outer surface 114 over the entire circumference. This forms an annular joining portion 430 in plan view, in which the outer edge portion of the protruding portion 420 is joined to the outer surface 114. Specifically, the joint 430 is a weld formed by welding the outer edge portion of the protrusion 420 and the outer surface 114 by laser welding or the like.

[2.2 description of the structure around the pouring outlet 111 of the lid body 110 ]

Next, the structure of the lid 110 around the pouring outlet 111 will be described in detail. The liquid inlet 111 is a through hole having a circular shape in plan view into which the shaft portion 410 is inserted, and injects the electrolyte solution into the inside of the container 100 through the liquid inlet 111. Liquid inlet 111 has an inner circumferential shape substantially identical to the outer circumferential shape of column part 412 of shaft part 410 in plan view. The lid 110 has a step 112 disposed around the pouring outlet 111. The step 112 is a stepped portion formed by a circular recess in plan view disposed around the liquid inlet 111. In other words, the stepped portion 112 is a portion formed by a bottom surface portion having an annular shape in plan view and a cylindrical side surface portion rising from an outer peripheral edge of the bottom surface portion.

The lid body 110 has a space 113 formed around the pouring outlet 111 and adjacent to the shaft 410 by the step 112. The space 113 is formed between the engagement portion 430 and the shaft portion 410, in other words, in a range from the abutment surface of the protrusion portion 420 and the outer surface 114 to the outer peripheral surface of the pillar portion 412. The space 113 is disposed between the inner surface of the protrusion 420 on the pillar portion 412 side and the bottom surface portion of the step portion 112. In other words, the space 113 is a space surrounded by the bottom surface portion and the side surface portion of the step portion 112, the outer peripheral surface of the pillar portion 412 of the shaft portion 410, and the inner surface of the protrusion portion 420 on the pillar portion 412 side.

In the liquid pouring stopper 400, the shaft portion 410 is inserted into the liquid pouring port 111 in a state where the space 113 is formed around the shaft portion 410, the outer protrusion 420 of the space 113 abuts against the outer surface 114 of the cover 110, and the engaging portion 430 is formed on the outer peripheral edge of the protrusion 420. Here, the shaft portion 410 is inserted into the liquid inlet 111 with the outer peripheral surface of the lower portion of the column portion 412 in contact with the inner peripheral surface of the liquid inlet 111. In the present embodiment, the outer peripheral surface of the lower portion of the column part 412 of the shaft part 410 abuts against the inner peripheral surface of the liquid pouring port 111 over the entire circumference, but only a part of the outer peripheral surface of the lower portion of the column part 412 may abut against the inner peripheral surface of the liquid pouring port 111.

The tip of the shaft 410 is disposed in the liquid inlet 111. In other words, the distal end portion 414 of the shaft portion 410 is disposed in the liquid inlet 111. In other words, the front end edge of the front end portion 414 is disposed on the Z-axis direction positive side of the inner surface 115 of the cover 110. In such a configuration, the arrangement of the shaft portion 410 in the liquid inlet 111 (the positional relationship between the distal end portion 414 and the space 113) is as follows.

The distance between the tip of the shaft portion 410 and the inner surface 115 of the lid body 110 in the axial direction of the shaft portion 410 is longer than the length of the portion of the shaft portion 410 in contact with the inner peripheral surface of the pouring outlet 111. In other words, the distance between the distal end 414 and the inner surface 115 (L1 in the figure) is greater than the length of the contact portion between the pillar 412 and the inner peripheral surface of the pouring outlet 111 (L2 in the figure) (L1 > L2) in the axial direction (Z-axis direction) of the shaft 410.

Further, the length of the portion of the shaft 410 in contact with the inner peripheral surface of the liquid inlet 111 is smaller than the length of the boundary portion between the shaft 410 and the space 113 in the axial direction of the shaft 410. In other words, the length of the portion of the column part 412 in contact with the inner peripheral surface of the liquid inlet 111 (L2 in the figure) is smaller than the length of the boundary portion between the column part 412 and the space 113 (L3 in the figure) in the axial direction (Z-axis direction) of the shaft part 410 (L2 < L3). In the present embodiment, L1 > L3 > L2 is used, but L1 ═ L3 > L2 or L3 > L1 > L2 may be used.

The shape of the shaft portion 410 is not limited to a cylindrical shape, and may be, for example, a prismatic shape, or the like, and the shape of the protruding portion 420 is not limited to a circular ring shape in plan view, and may be, for example, an elliptical, oval, or polygonal ring shape in plan view. The shape of the liquid inlet 111 is not limited to a circular shape in plan view, and may be, for example, an elliptical shape, an oval shape, a polygonal shape, or the like in plan view, or may be a shape different from the outer peripheral shape of the shaft portion 410 or a size different from the outer peripheral shape. The shape and size of the step 112 are not particularly limited.

[3 Explanation of Effect ]

As described above, according to the electric storage element 10 of the embodiment of the present invention, the lid body 110 as the wall portion of the container 100 is formed with the space 113 adjacent to the shaft portion 410 of the pouring plug 400 around the pouring port 111, and the tip of the shaft portion 410 of the pouring plug 400 is disposed in the pouring port 111. In other words, when the electrolyte adheres to the shaft portion 410 of the liquid injection plug 400, the electrolyte enters between the shaft portion 410 and the inner circumferential surface of the liquid injection port 111 and rises, but the larger the contact area between the shaft portion 410 and the inner circumferential surface of the liquid injection port 111, the larger the amount of the electrolyte that enters and rises. Therefore, the space 113 adjacent to the shaft portion 410 of the liquid pouring plug 400 is formed around the liquid pouring port 111, and the tip end of the shaft portion 410 of the liquid pouring plug 400 is disposed in the liquid pouring port 111, so that the contact area between the shaft portion 410 and the inner peripheral surface of the liquid pouring port 111 is reduced, and the amount of the electrolyte that enters between the shaft portion 410 and the inner peripheral surface of the liquid pouring port 111 and ascends is reduced. Further, when the distal end of the shaft portion 410 of the liquid pouring stopper 400 is disposed in the liquid pouring port 111, the distal end of the shaft portion 410 functions as a cover, and the electrolyte solution adhering to the lower side than the distal end of the shaft portion 410 of the liquid pouring stopper 400 in the liquid pouring port 111 can be prevented from entering between the shaft portion 410 and the inner peripheral surface of the liquid pouring port 111. This can suppress the electrolyte from rising from the injection port 111. Further, by forming the space 113 adjacent to the shaft portion 410 of the liquid pouring stopper 400 around the liquid pouring port 111, the electrolyte can be stored in the space 113, and thus the electrolyte can be further prevented from rising from the liquid pouring port 111. Accordingly, a bonding failure (welding failure) between the filling plug 400 and the lid body 110 can be suppressed.

Further, when the pouring outlet 111 is formed, a burr may be generated which protrudes from the inner peripheral surface of the pouring outlet 111 toward the protruding portion 420 of the pouring stopper 400. In this case, if the space 113 is not formed around the pouring outlet 111, the burr interferes with the projecting portion 420 of the pouring stopper 400, and the projecting portion 420 is lifted up, which may cause a poor joint between the projecting portion 420 and the lid body 110. Therefore, by forming the space 113 around the pouring outlet 111, it is possible to suppress the protrusion 420 from being lifted due to interference between the burr and the protrusion 420, and to suppress a poor joint between the protrusion 420 and the lid body 110.

Further, since the shaft portion 410 is provided in the pouring plug 400, the pouring plug 400 can be easily disposed in the pouring port 111 by inserting the shaft portion 410 into the pouring port 111, and the pouring plug 400 can be easily joined to the lid body 110. This can suppress a defective joint between the filling stopper 400 and the cover 110.

In the electric storage device 10, the distance (L1) between the tip of the shaft portion 410 and the inner surface 115 of the lid body 110 of the container 100 in the axial direction of the shaft portion 410 of the liquid pouring stopper 400 is larger than the length (L2) of the portion of the shaft portion 410 that abuts against the inner peripheral surface of the liquid pouring outlet 111. In this way, by increasing the distance (L1) between the tip of the shaft portion 410 and the inner surface 115 of the lid body 110 and decreasing the length (L2) of the portion of the shaft portion 410 in contact with the inner peripheral surface of the liquid pouring outlet 111, the area of contact between the shaft portion 410 and the inner peripheral surface of the liquid pouring outlet 111 is decreased, and the amount of electrolyte that enters between the shaft portion 410 and the inner peripheral surface of the liquid pouring outlet 111 is decreased. This can further suppress the rising of the electrolyte solution from the liquid inlet 111.

In the electric storage element 10, the length (L2) of the portion of the shaft portion 410 in contact with the inner peripheral surface of the liquid inlet 111 in the axial direction of the shaft portion 410 of the liquid injection plug 400 is smaller than the length (L3) of the boundary portion between the shaft portion 410 and the space 113. In this way, by reducing the length (L2) of the contact portion between the shaft portion 410 and the inner peripheral surface of the liquid inlet 111 and increasing the length (L3) of the boundary portion between the shaft portion 410 and the space 113, the contact area between the shaft portion 410 and the inner peripheral surface of the liquid inlet 111 can be reduced, and the liquid pool of the electrolyte can be increased. This can further suppress the rising of the electrolyte solution from the liquid inlet 111.

[4 description of modified example of embodiment ]

(modification examples 1 and 2)

Next, modifications 1 and 2 of the above embodiment will be described. FIG. 5 is a sectional view showing the structure around the pouring outlet 111 of the lid body 110a of modification example 1 of the present embodiment and the structure of the pouring stopper 400. Fig. 6 is a cross-sectional view showing the structure around the pouring outlet 111 of the lid body 110b of modification example 2 of the present embodiment and the structure of the pouring stopper 400. Fig. 5 and 6 correspond to fig. 4 of the above embodiment.

As shown in fig. 5, the cover 110a of modification 1 has a step 112a instead of the step 112 of the cover 110 of the above embodiment. The step portion 112a is formed to be lower than the step height (step position height) of the step portion 112 of the above embodiment. Thus, the lid body 110a has a space 113a formed around the pouring outlet 111 and having a height lower than that of the space 113 in the above embodiment. Other configurations of the present modification are the same as those of the above embodiment, and therefore, the description thereof is omitted.

With such a configuration, the distance (L1 in the drawing) between the tip of the shaft portion 410 and the inner surface 115 of the lid body 110a in the axial direction (Z-axis direction) of the shaft portion 410 is larger than the length (L4 in the drawing) of the contact portion between the shaft portion 410 and the inner peripheral surface of the pouring outlet 111 (L1 > L4). Further, the length of the portion of the shaft 410 in contact with the inner peripheral surface of the liquid inlet 111 (L4 in the figure) is greater than the length of the boundary portion between the shaft 410 and the space 113a (L5 in the figure) (L4 > L5) in the axial direction (Z-axis direction) of the shaft 410. In other words, in the present modification, L1 > L4 > L5 is defined.

As shown in fig. 6, the cover 110b of modification 2 has a step 112b instead of the step 112a of the cover 110a of modification 1. The step 112b is formed to be lower in height (higher in step position) than the step 112a of the modification 1. Thus, the lid body 110b is formed with a space 113b around the pouring outlet 111, which is lower in height than the space 113a in modification 1. The other configurations of this modification are the same as those of modification 1, and therefore, the description thereof is omitted.

With such a configuration, the distance (L1 in the drawing) between the tip of the shaft portion 410 and the inner surface 115 of the lid body 110b in the axial direction (Z-axis direction) of the shaft portion 410 is smaller than the length (L6 in the drawing) of the contact portion between the shaft portion 410 and the inner peripheral surface of the pouring outlet 111 (L1 < L6). Further, the length of the portion of the shaft 410 in contact with the inner peripheral surface of the liquid inlet 111 (L4 in the figure) is greater than the length of the boundary portion between the shaft 410 and the space 113b (L7 in the figure) (L6 > L7) in the axial direction (Z-axis direction) of the shaft 410. In the present modification, L6 > L1 > L7 is used, but L6 > L1 ═ L7 or L6 > L7 > L1 may be used.

As described above, according to the power storage devices of modifications 1 and 2, since the step heights of the step portions 112a and 112b are formed to be low (the step positions are high), the step portions 112a and 112b can be easily formed.

(modification 3)

Next, modification 3 of the above embodiment will be explained. FIG. 7 is a sectional view showing the structure around the pouring outlet 111 of the lid body 110c of modification example 3 of the present embodiment and the structure of the pouring stopper 400. Fig. 7 is a view corresponding to fig. 4 of the above embodiment.

As shown in fig. 7, the cover 110c of the present modification includes a step 112c instead of the step 112 of the cover 110 of the above embodiment. Step portion 112c has, as a bottom surface, inclined surface 116 inclined toward the inside of container 100 as it goes toward pouring port 111. Thus, the lid body 110c has a space 113c formed around the pouring outlet 111 and having a height that increases toward the pouring outlet 111. In other words, the lid 110c has the inclined surface 116 which is disposed adjacent to the space 113c and is inclined toward the inside of the container 100 as it goes toward the pouring outlet 111. Other configurations of the present modification are the same as those of the above embodiment, and therefore, the description thereof is omitted.

In the present modification, the inclined surface 116 is inclined linearly toward the inside of the container 100 as it goes toward the pouring port 111, but may be inclined in a curved shape or may have another shape.

As described above, according to the power storage element of the present modification, the same effects as those of the above embodiment can be obtained. In particular, since the lid body 110c of the container 100 has the inclined surface 116 inclined toward the inside of the container 100 as it goes toward the liquid inlet 111, the inclined surface 116 can suppress the rising of the electrolyte. This can further suppress the rising of the electrolyte solution from the liquid inlet 111.

(modification 4)

Next, a modified example 4 of the above embodiment will be explained. FIG. 8 is a sectional view showing the structure around the pouring outlet 111 of the lid body 110d of modification example 4 of the present embodiment and the structure of the pouring stopper 400. Fig. 8 is a view corresponding to fig. 4 of the above embodiment.

As shown in fig. 8, the cover 110d of the present modification includes a step 112d instead of the step 112 of the cover 110 of the above embodiment. The step portion 112d has a recess 117 in the bottom surface. In other words, the recess 117 is an annular recess in plan view formed on the surface of the step portion 112d facing the protrusion 420. Thus, the cover 110d has a recess 117 disposed adjacent to the space 113 d. Other configurations of the present modification are the same as those of the above embodiment, and therefore, the description thereof is omitted. The shape and cross-sectional shape of the recess 117 in plan view are not particularly limited, and the size is not limited.

As described above, according to the power storage element of the present modification, the same effects as those of the above embodiment can be obtained. In particular, since the electrolyte can be stored in the recess 117 by disposing the recess 117 adjacent to the space 113d, the electrolyte can be further suppressed from rising from the liquid inlet 111.

(modification 5)

Next, a modified example 5 of the above embodiment will be explained. FIG. 9 is a sectional view showing the structure around the pouring outlet 111 of the lid body 110e of modification example 5 of the present embodiment and the structure of the pouring stopper 400. Fig. 9 is a view corresponding to fig. 4 of the above embodiment.

As shown in fig. 9, the cover 110e of the present modification includes a step 112e instead of the step 112 of the cover 110 of the above embodiment. The step portion 112e has a convex portion 118 on the bottom surface. In other words, the projection 118 is an annular projection in plan view formed on the surface of the step portion 112e facing the projection 420. Thus, the cover 110e has the projection 118 disposed adjacent to the space 113 e. Other configurations of the present modification are the same as those of the above embodiment, and therefore, the description thereof is omitted. The shape and cross-sectional shape of the projection 118 in plan view are not particularly limited, and the size is not limited.

As described above, according to the power storage element of the present modification, the same effects as those of the above embodiment can be obtained. In particular, by disposing the convex portion 118 adjacent to the space 113e, the convex portion 118 can serve as a wall to suppress rising of the electrolyte, and thus the rising of the electrolyte from the liquid inlet 111 can be further suppressed.

The above description has been given of the power storage element according to the embodiment and the modifications thereof, but the present invention is not limited to the above embodiment and the modifications. In other words, the embodiment and its modified examples disclosed herein are not intended to be limiting but are illustrative in all respects. The scope of the present invention is defined by the scope of the claims rather than the description above, and is intended to include all modifications within the scope and meaning equivalent to the meaning of the claims.

For example, in the above-described embodiment and its modified examples, the lid body of the container 100 is provided with a stepped portion in one step around the pouring outlet 111. However, the lid body of the container 100 may be provided with a step portion of two or more steps around the pouring port 111. The shape of the periphery of the step portion on the outer surface 114 of the lid body of the container 100 is not particularly limited, and, for example, a concave portion, a convex portion, or the like may be formed around the step portion on the outer surface 114.

In the above-described embodiment and the modifications thereof, the joining portion 430 is a welded portion formed by joining the protrusion 420 of the filling stopper 400 and the lid body of the container 100 by laser welding. However, the method of joining the protrusion 420 and the lid body is not limited to laser welding, and welding by resistance welding, ultrasonic welding, or the like may be used. The joining method is not limited to welding, and the joining portion 430 may be a portion where the protrusion 420 of the filling stopper 400 and the lid body of the container 100 are joined mechanically by bonding with an adhesive or the like, welding with heat welding or the like, or caulking, for example. In this case, the electrolyte solution is prevented from rising from the injection port 111, and thus, the poor connection between the injection plug 400 and the lid body can be prevented.

In the above-described embodiment and the modification thereof, the pouring outlet 111 is formed in the lid body of the container 100, and the pouring stopper 400 is disposed on the lid body of the container 100 so as to close the pouring outlet 111. However, the pouring outlet 111 may be formed in any wall portion of the container body 120, and the pouring stopper 400 may be disposed on the wall portion of the container body 120 so as to close the pouring outlet 111.

Further, a configuration in which the constituent elements included in the above-described embodiment and the modifications thereof are arbitrarily combined is also included in the scope of the present invention.

The present invention can be realized not only as an electric storage device, but also as a container 100 having a lid as a wall portion and a filling stopper 400 provided in the electric storage device.

Industrial applicability of the invention

The present invention can be applied to an electric storage element such as a lithium ion secondary battery.

Description of reference numerals:

10 electric storage element

100 container

110. 110a, 110b, 110c, 110d, 110e cover

111 liquid filling opening

113. 113a, 113b, 113c, 113d, 113e space

115 inner surface

116 inclined plane

117 recess

118 convex part

400 liquid filling plug

410 shaft part

414 front end portion

420 projection

430 engaging portion.