Energy storage device and method for manufacturing energy storage device

Abstract

A power storage element is provided with: a container having a liquid injection port for injecting an electrolyte; the liquid injection cover is used for sealing the liquid injection opening from the outer side of the container; and a middle cover that is interposed between the liquid injection port and the liquid injection cover and covers the liquid injection port, the middle cover having insulating properties and having a shape protruding toward the outside of the container.

Description

Technical Field

[0001] The present invention relates to an electric storage element and a method for manufacturing the electric storage element. Background Art

[0002] There are known storage elements having a container, a terminal, a current collector, and a gasket (for example, Patent Document 1). Patent Document 1 discloses a storage element (secondary battery) having a container (battery cover), terminals (positive and negative electrode terminals), a gasket (insulating sealing member) for insulating the terminals and the container, a current collector (positive and negative electrode current collector), and a gasket (insulating member) between the current collector and the container.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2013-93160 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] However, the electric storage device described in Patent Document 1 does not take into consideration, for example, how to prevent fragments of a liquid filling cap sealing the liquid filling port from entering the container from the liquid filling port when the electrolyte is refilled into the container from the liquid filling port.

[0008] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an electric storage element capable of preventing fragments of a liquid filling cap sealing a liquid filling port from entering a container through the liquid filling port.

[0009] Means used to solve problems

[0010] A storage element according to one embodiment of the present invention comprises: a container having a liquid injection port for injecting electrolyte; a liquid injection cap for sealing the liquid injection port from the outside of the container; a middle cover interposed between the liquid injection port and the liquid injection cap and covering the liquid injection port, the middle cover being insulating and having a shape protruding toward the outside of the container.

[0011] A method for manufacturing an electric storage element according to an embodiment of the present invention comprises: a container having an injection port for injecting electrolyte; a first injection cap for sealing the injection port from the outside of the container; and a first middle cap interposed between the injection port and the injection cap to cover the injection port. An opening is formed by cutting off a portion of the first injection cap, the first middle cap is removed through the opening, electrolyte is injected into the container through the opening, and the opening is covered with a second injection cap.

[0012] A method for manufacturing an electric storage element according to an embodiment of the present invention comprises: a container having an injection port for injecting electrolyte; a first injection cap for sealing the injection port from the outside of the container; and a middle cap interposed between the injection port and the injection cap to cover the injection port. An opening is formed by cutting off a part of the first injection cap, a hole is formed in the middle cap, the electrolyte is injected into the container through the opening and the hole, and the opening is covered with a second injection cap.

[0013] Effects of the Invention

[0014] According to the electric storage device of the present invention, it is possible to effectively prevent fragments of the liquid filling cap sealing the liquid filling port from entering the container through the liquid filling port. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a perspective view showing the appearance of the electric storage element according to the first embodiment.

[0016] Figure 2 This is an exploded perspective view showing each component by disassembling the electric storage device according to the first embodiment.

[0017] Figure 3 It is a side cross-sectional view schematically showing the middle cover and the like according to the first embodiment.

[0018] Figure 4 It is a figure which shows the manufacturing method of the refill liquid of 2nd Embodiment.

[0019] Figure 5 It is a figure which shows the manufacturing method of the refill liquid of 3rd embodiment.

[0020] Figure 6 It is a diagram showing a method for producing refill liquid according to a fourth embodiment.

[0021] Figure 7 It is a figure which shows the manufacturing method of the refill liquid of 5th Embodiment.

[0022] Figure 8 It is a side cross-sectional view schematically showing the middle cover and the like according to the sixth embodiment.

[0023] Fig. 9 It is a side cross-sectional view schematically showing the middle cover and the like according to the seventh embodiment.

[0024] Fig.10 It is a side cross-sectional view schematically showing the middle cap and the like after refilling according to the seventh embodiment. DETAILED DESCRIPTION

[0025] (1) An electric storage element according to one embodiment of the present invention comprises: a container having a liquid injection port for injecting an electrolyte; a liquid injection cap for sealing the liquid injection port from the outside of the container; and a middle cap interposed between the liquid injection port and the liquid injection cap and covering the liquid injection port, the middle cap having insulating properties and being convex toward the outside of the container.

[0026] According to the electric storage device of the embodiment (1) above, the middle cover covers the liquid injection port and has a shape that protrudes toward the outside of the container. This can prevent fragments of the liquid injection cap that seals the liquid injection port from entering the container through the liquid injection port.

[0027] (2) In the electric storage device described in (1) above, a tip of the protruding shape of the middle cover may be in contact with the liquid filling cap.

[0028] According to the storage element described in (2) above, the top end of the convex shape of the middle cover contacts the liquid filling cap. That is, when the middle cover contacts the inner surface of the liquid filling cap, the liquid filling cap seals the liquid filling port from the outside of the container. By adopting such a structure, the state in which the middle cover covers the liquid filling port can be effectively maintained. Furthermore, the positional deviation of the middle cover can be suppressed, that is, the movement of the middle cover in the space between the cover body of the container having the liquid filling port and the liquid filling cap can be suppressed.

[0029] (3) In the energy storage device described in (1) or (2) above, the liquid injection port is formed by a protrusion that protrudes cylindrically from the outer surface of the container, and the middle cover surrounds the protrusion from the liquid injection cap side.

[0030] According to the storage element described in (3) above, the bottomed cylindrical (one end of the cylindrical shape is open and the other end is closed) middle cover surrounds the protruding portion so that the opening of the bottomed cylindrical shape faces the protruding portion and covers the cylindrical protruding portion from the outer peripheral side. With such a structure, the middle cover is not easily detached from the protruding portion, and when the liquid filling cap is removed from the container, foreign matter can be further suppressed from entering the interior of the container from the liquid filling port.

[0031] (4) A method for manufacturing an electric storage element according to an embodiment of the present invention, the electric storage element comprising: a container having an injection port for injecting an electrolyte; a first injection cap for sealing the injection port from the outside of the container; and a first middle cap interposed between the injection port and the first injection cap to cover the injection port. The opening is formed by cutting off a portion of the first injection cap, the first middle cap is removed through the opening, the electrolyte is injected into the container through the opening, and the opening is covered with the second injection cap.

[0032] (5) A method for manufacturing an electric storage element according to an embodiment of the present invention, the electric storage element comprising: a container having an injection port for injecting electrolyte; a first injection cap for sealing the injection port from the outside of the container; and a middle cap interposed between the injection port and the first injection cap to cover the injection port. The opening is formed by cutting off a portion of the first injection cap, a hole is formed in the middle cap, the electrolyte is injected into the container through the opening and the hole, and the opening is covered with the second injection cap.

[0033] According to the method for manufacturing the storage element of the embodiments (4) and (5), when a part of the first liquid filling cap is cut off, a cut piece is generated, but the middle cap (first middle cap) prevents the cut piece from entering the container from the liquid filling port. Therefore, when the storage element is reused, it is possible to prevent the performance of the storage element from being degraded due to the cut piece entering the container (metal contamination).

[0034] (6) In the method for manufacturing an electric storage device described in (4) above, in the step of covering the opening with the second liquid filling cap, a first middle cap or a second middle cap different from the first middle cap is disposed between the second liquid filling cap and the liquid filling port.

[0035] According to the storage element described in (6) above, since the filling port is still covered with the middle cover after refilling, when refilling for the second time, the cut pieces produced when a part of the second filling cap is cut off can be prevented from intruding into the container from the filling port.

[0036] Hereinafter, the storage element of the embodiment (and its variant) of the present invention will be described with reference to the accompanying drawings. In addition, the embodiments described below all represent general examples or specific examples. The numerical values, shapes, materials, constituent elements, configuration positions and connection methods of constituent elements, manufacturing processes, the order of manufacturing processes, etc. shown in the following embodiments are examples, and their main purpose is not to limit the present invention. In addition, for the constituent elements of the following embodiments that are not recorded in the independent claims representing the highest concept, they are described as arbitrary constituent elements. In addition, in each figure, the dimensions, etc. are not strictly illustrated.

[0037] In the following description and drawings, the following directions are defined as the X-axis direction: the arrangement direction of a pair of terminals (positive and negative, the same below) of the storage element, the arrangement direction of a pair of current collectors, the arrangement direction of a pair of upper pads, the arrangement direction of a pair of lower pads, the arrangement direction of both ends of the electrode body (a pair of active material layer unformed parts), the winding axis direction of the electrode body, or the facing direction of the short side of the container. In addition, the following directions are defined as the Y-axis direction: the facing direction of the long side of the container, the short side direction of the short side of the container, the thickness direction of the container, or the arrangement direction of the foot (electrode body connection part) in a collector. In addition, the following directions are defined as the Z-axis direction: the arrangement direction of the container body and the cover of the storage element, the length direction of the short side of the container, or the extension direction of the foot (electrode body connection part) of the collector. These X-axis direction, Y-axis direction, and Z-axis direction are directions that intersect each other (orthogonal in this embodiment). In the following description, for example, the positive X-axis direction indicates the direction of the arrow of the X-axis, and the negative X-axis direction indicates the direction opposite to the positive X-axis direction. The same applies to the Y-axis direction and the Z-axis direction.

[0038] (First Embodiment)

[0039] Hereinafter, the present invention will be described in detail based on the drawings showing the embodiments thereof. Figure 1 It is a perspective view showing the appearance of the electric storage element according to the first embodiment. Figure 2 This is an exploded perspective view showing each component of the electric storage device according to the first embodiment by disassembling it. Figure 1 and Figure 2 , the energy storage element 10 in this embodiment will be described as a whole.

[0040] The storage element 10 is a secondary battery that can be charged or discharged, specifically, a non-aqueous electrolyte secondary battery such as a lithium-ion secondary battery. The storage element 10 is used, for example, as a power source for automobiles such as electric vehicles (EV), hybrid electric vehicles (HEV) or plug-in hybrid electric vehicles (PHEV), a power source for electronic equipment, a power source for power storage, etc. In addition, the storage element 10 is not limited to non-aqueous electrolyte secondary batteries, but may also be a secondary battery other than non-aqueous electrolyte secondary batteries, or a capacitor. In addition, the storage element 10 may also be a primary battery. Furthermore, the storage element 10 may be a battery using a solid electrolyte. In addition, in the present embodiment, a storage element 10 in the shape of a rectangular parallelepiped (square) is illustrated, but the shape of the storage element 10 is not limited to a rectangular parallelepiped shape, but may also be a cylindrical shape, a long cylindrical shape, or a polygonal prism shape other than a rectangular parallelepiped, etc.

[0041] As shown in the figure in this embodiment, the energy storage element 10 includes a container 100, positive and negative terminals 200, and positive and negative upper gaskets 300. In addition, positive and negative insulating members 400, positive and negative current collectors 500, and an electrode body 600 are accommodated inside the container 100. The insulating member 400 is made of an insulating resin plate and can function as a lower gasket.

[0042] The container 100 is filled with an electrolyte (non-aqueous electrolyte), but the illustration is omitted. As the electrolyte, there is no particular restriction on its type as long as it does not damage the performance of the storage element 10, and various electrolytes can be selected. In addition to the above-mentioned components, a spacer, an insulating film, etc. can also be configured, the spacer is configured on the side of the collector 500 of the positive electrode and the negative electrode, and the insulating film wraps the electrode body 600, etc.

[0043] The container 100 is composed of a container body 110 having a rectangular cylindrical shape and a bottom and a plate-like member, i.e., a cover 120, which is a cover that seals an opening 111 of the container body 110. In addition, after the electrode body 600 and the like are accommodated inside the container 100, the inside can be sealed by welding the container body 110 and the cover 120. In addition, the material of the container body 110 and the cover 120 is not particularly limited, for example, it can be a weldable metal such as stainless steel, aluminum, and aluminum alloy, but resin can also be used. In addition, a gas discharge valve 121 for releasing the pressure when the pressure inside the container 100 rises and a liquid injection port 130 for injecting electrolyte into the inside of the container 100 can also be provided on the cover 120.

[0044] On the outer surface of the cover body 120, a liquid injection cap 140 is provided to cover the liquid injection port 130. The liquid injection cap 140 seals the liquid injection port 130 from the outside of the container 100. Between the liquid injection port 130 provided in the cover body 120 and the liquid injection cap 140, a middle cover 150 covering the liquid injection port 130 is provided. The middle cover 150 is formed of a resin such as polycarbonate (PC), polypropylene (PP), polyethylene (PE), or polyphenylene sulfide resin (PPS), and has insulating properties. The details of the liquid injection cap 140 and the middle cover 150 will be described later.

[0045] The electrode body 600 has a positive plate, a negative plate and a separator, and is an electric storage element (power generation element) capable of storing electric energy. The positive plate refers to a plate having a positive active material layer formed on a long strip-shaped collector foil, i.e., a positive electrode substrate layer, made of aluminum or an aluminum alloy. The negative plate refers to a plate having a negative active material layer formed on a long strip-shaped collector foil, i.e., a negative electrode substrate layer, made of copper or a copper alloy. In addition, as the above-mentioned collector foil, well-known materials such as nickel, iron, stainless steel, titanium, sintered carbon, conductive polymers, conductive glass, and Al-Cd alloys can also be appropriately used. In addition, as the positive active material and the negative active material used for the positive active material layer and the negative active material layer, well-known materials can be appropriately used as long as they are active materials that can absorb and release lithium ions. In addition, the separator can use, for example, a microporous sheet or non-woven fabric made of a resin.

[0046] The electrode body 600 is formed by arranging a separator between the positive electrode plate and the negative electrode plate and winding them. Specifically, in the electrode body 600, the positive electrode plate and the negative electrode plate are wound staggered with each other in the direction of the winding axis (in this embodiment, an imaginary axis parallel to the X-axis direction) separated by the separator. In addition, the positive electrode plate and the negative electrode plate have portions (active material layer unformed portions) that are not coated with active material (active material layer is not formed) and expose the substrate layer at the ends of each staggered direction. That is, the electrode body 600 has a positive electrode bundling portion at one end 610 where the active material layer unformed portions of the positive electrode plates are stacked and bundled, and the electrode body 600 has a negative electrode bundling portion at the other end 610 where the active material layer unformed portions of the negative electrode plates are stacked and bundled. In addition, in this embodiment, an oblong is illustrated as the cross-sectional shape of the electrode body 600, but it may also be a circle or an ellipse, etc.

[0047] The terminal 200 is a terminal (positive terminal and negative terminal) electrically connected to the positive electrode plate and the negative electrode plate of the electrode body 600 via the current collector 500. That is, the terminal 200 is a metal member for conducting the electric energy stored in the electrode body 600 to the external space of the electric storage element 10, and for conducting the electric energy to the internal space of the electric storage element 10 in order to store the electric energy in the electrode body 600. In addition, the terminal 200 is mounted on the cover 120 disposed above the electrode body 600. Specifically, as Figure 2 As shown, the shaft portion 210 of the terminal 200 is inserted into the through hole 300a of the upper gasket 300, the through hole 120a of the cover 120, the through hole 410a of the insulating member 400 (lower gasket), and the through hole 510a of the collector 500, and is fixed to the cover 120 together with the collector 500 by crimping. In addition, the terminal 200 is formed of aluminum, aluminum alloy, copper, copper alloy, etc.

[0048] The current collector 500 is disposed on both sides of the electrode body 600 in the X-axis direction and is a member (positive electrode current collector and negative electrode current collector) connected to the end 610 of the electrode body 600. Specifically, the current collector 500 is a conductive and rigid member disposed between the end 610 of the electrode body 600 and the side wall of the container body 110, and electrically connects the positive electrode bundle and the negative electrode bundle at the end 610 of the electrode body 600 to the terminal 200. In addition, the current collector 500 is fixedly connected (joined) to the cover 120 and the end 610 of the electrode body 600. With this structure, the electrode body 600 is held (supported) by the current collector 500 in a state suspended from the cover 120, thereby suppressing shaking caused by vibration or impact. In addition, the material of the collector 500 is not limited. For example, the collector 500 on the positive electrode side can be formed of aluminum or aluminum alloy like the positive electrode substrate layer of the electrode body 600, and the collector 500 on the negative electrode side can be formed of copper or copper alloy like the negative electrode substrate layer of the electrode body 600.

[0049] The upper gasket 300 is a member (positive upper gasket and negative upper gasket) disposed between the cover 120 and the terminal 200 of the container 100 to insulate and seal between the cover 120 and the terminal 200. Specifically, the upper gasket 300 is shaped such that a through hole 300a for inserting the shaft 210 of the terminal 200 is formed in the central portion of a rectangular substantially plate-shaped member, and the shaft 210 is inserted into or crimped into the through hole 300a, thereby fixing the upper gasket 300 to the cover 120. The upper gasket 300 is formed of a resin such as polycarbonate (PC), polypropylene (PP), polyethylene (PE), or polyphenylene sulfide resin (PPS).

[0050] The insulating member 400 (lower gasket) is a member (positive electrode insulating member and negative electrode insulating member) disposed between the cover 120 and the current collector 500 of the container 100 to insulate between the cover 120 and the current collector 500. Specifically, the insulating member 400 has a shape in which a through hole 410a for inserting the shaft portion 210 of the terminal 200 is formed in the substantially central portion of a rectangular substantially plate-shaped member, and the insulating member 400 is fixed to the cover 120 by inserting or crimping the shaft portion 210 into the through hole 410a. The insulating member 400 is formed of a resin such as PC, PP, PE, or PPS.

[0051] Figure 3 1 is a side cross-sectional view schematically showing the middle cover etc. of the first embodiment. A circular through hole is formed on the cover 120 that closes the opening 111 of the container body 110, and a liquid injection port 130 for injecting electrolyte is formed through the through hole. The liquid injection port 130 is provided, for example, between the gas discharge valve 121 and the terminal 200.

[0052] The cover 120 may be provided with, for example, a circular recess 132, and a liquid injection port 130 (through hole) may be formed at the center of the recess 132. By providing the recess 132, a step is formed on the outer surface of the cover 120.

[0053] The middle cover 150 is provided in a manner to cover the liquid injection port 130 from the outer surface side of the cover body 120. The middle cover 150 is made of, for example, resin and has insulating properties. The middle cover 150 is in a shape that protrudes toward the outside of the container 100. Specifically, the middle cover 150 is in a cylindrical shape, one end of which is open, and the other end has a bottom 151 (bottomed cylindrical shape). The shape of the middle cover 150 is such that the closer to the opening, the larger the cross-sectional area of ​​the cylinder. At the end of the opening of the middle cover 150, a flange-shaped peripheral portion 152 extending from the opening to the outer peripheral side may also be provided.

[0054] The middle cover 150 is arranged so that the opening faces the liquid injection port 130 and covers the liquid injection port 130. At this time, the flange-shaped peripheral edge portion 152 located on the outer periphery of the opening is arranged in the recessed portion 132 formed with the liquid injection port 130. The inner diameter of the circular recessed portion 132 and the outer diameter of the peripheral edge portion 152 of the middle cover 150 are configured to be substantially the same length. Thus, the middle cover 150 is fitted into the recessed portion 132, and the movement or displacement of the middle cover 150 relative to the cover body 120 can be restricted or suppressed.

[0055] When the middle cover 150 is fitted into the recess 132 and arranged on the outer surface of the cover body 120, the bottom 151 of the middle cover 150 is set to protrude further than the outer surface of the cover body 120. That is, the cylindrical middle cover 150 protrudes from the recess 132 by the length of the cylinder. The bottom 151 of the middle cover 150 protrudes further outward than the outer surface of the cover body 120.

[0056] The liquid injection cap 140 is in the shape of a tube, one end of which is open, and the other end of which has a bottom plate 141. The shape of the liquid injection cap 140 is such that the cross-sectional area of ​​the tube increases as it approaches the opening. An annular (flange-shaped) joint portion 143 extending from the opening to the outer peripheral side is provided at the opening end of the liquid injection cap 140.

[0057] The portion of the tube is located between the joint 143 and the bottom plate 141. In the tube, the portion adjacent to the joint 143 corresponds to the location (cut-off portion 142) where the liquid injection cap 140 is cut off. By cutting the liquid injection cap 140 with the cut-off portion 142, a portion of the liquid injection cap 140 can be separated (detached) from the cover body 120.

[0058] The liquid injection cap 140 is configured to open toward the bottom 151 of the middle cover 150 and cover the middle cover 150. As described above, since the middle cover 150 is provided in a manner to cover the liquid injection port 130, the liquid injection cap 140 is formed to cover the middle cover 150 and the liquid injection port 130, thereby sealing the liquid injection port 130 from the outside of the container 100.

[0059] The liquid filling cap 140 is fixed to the cover body 120 by engaging the joint portion 143 of the liquid filling cap 140 with the outer surface of the cover body 120. At this time, the outer surface of the bottom 151 of the middle cover 150 faces the inner surface of the bottom plate 141 of the liquid filling cap 140. Furthermore, the inner surface of the bottom plate 141 of the liquid filling cap 140 contacts or presses the outer surface of the bottom 151 of the middle cover 150.

[0060] When the liquid injection port 130 formed in the cover body 120 and the inner surface of the bottom plate 141 of the liquid injection cap 140 that seals the liquid injection port 130 are separated, a space is formed between the cover body 120 and the liquid injection cap 140. At this time, the bottom 151 of the middle cover 150 is in contact with the inner surface of the bottom plate 141 of the liquid injection cap 140 or is pressed by the inner surface of the bottom plate 141 of the liquid injection cap 140, so that the position deviation of the middle cover 150 can be suppressed.

[0061] (Second Embodiment)

[0062] Figure 4 It is a figure which shows the manufacturing method of the refill liquid of 2nd Embodiment. Figure 4 (A) to (D) show the states from the state before the refilling of the second embodiment to the state in which the liquid filling port 130 is sealed after the refilling.

[0063] Figure 4 (A) is a diagram showing a state before refilling. The middle cover 150 is disposed between the liquid filling port 130 and the first liquid filling cap 140. The liquid filling port 130 is sealed by welding the joint 143 of the first liquid filling cap 140 and the cover body 120.

[0064] Figure 4 (B) is a diagram showing a state where a portion of the first liquid filling cap 140 is cut off. By cutting off the cut portion 142 of the first liquid filling cap 140, the bottom plate 141 of the first liquid filling cap 140 is removed, thereby forming the opening 160. When the cut portion 142 is cut off, the presence of the middle cover 150 can prevent the cut pieces generated by the cut from intruding into the interior of the container 100 through the liquid filling port 130.

[0065] Figure 4 (C) is a diagram showing a state where the middle cover 150 is removed. The middle cover 150 is removed from the opening 160. After the middle cover 150 is removed, the electrolyte is injected into the container 100 through the opening 160 and the liquid injection port 130. That is, the container 100 is refilled through the opening 160 and the liquid injection port 130.

[0066] Figure 4(D) is a diagram showing a state where the second liquid injection cap 1401 is arranged after re-injection. The second liquid injection cap 1401 is shaped to cover the liquid injection port 130 and the joint 143 of the first liquid injection cap 140. The second liquid injection cap 1401 is arranged in such a manner that the second liquid injection cap 1401 covers the liquid injection port 130 and the joint 143 of the first liquid injection cap 140. Then, the connecting portion 1431 of the second liquid injection cap 1401 and the cover body 120 are welded. The liquid injection port 130 is sealed by this welding.

[0067] (Third Embodiment)

[0068] Figure 5 It is a figure which shows the manufacturing method of the refill liquid of 3rd embodiment. Figure 5 (A) to (D) represent the state from the state before refilling in the third embodiment to the state until the liquid filling port 130 is sealed after refilling. Except for the shape of the middle cover 1501, it is the same as the second embodiment. The middle cover can be a plate-shaped middle cover like the middle cover 1501 of this embodiment. In the case of using a plate-shaped middle cover, in order to fix the middle cover 1501, the middle cover 1501 can be joined to the container 100 using an adhesive or the like. In addition, the middle cover 1501 has a convex portion, a part of which can be inserted into the liquid filling port 130. The convex portion can be used to suppress the movement of the middle cover 1501.

[0069] (Fourth Embodiment)

[0070] Figure 6 It is a diagram showing a method for producing refill liquid according to a fourth embodiment. Figure 6 (A) to (D) show the states from the state before the refilling of the fourth embodiment to the state in which the liquid filling port 130 is sealed after the refilling. Figure 6 (A) and Figure 6 The step (B) is the same as that of the third embodiment.

[0071] Figure 6 (C) is a diagram of injecting electrolyte. In the third embodiment, the middle cover 1501 is removed from the opening 160, but in this embodiment, the middle cover 1501 is not removed. In this embodiment, a syringe is used for refilling. Specifically, the needle of the syringe is inserted into the middle cover 1501 to form a hole 170 in the middle cover, and the electrolyte is injected into the interior of the container 100 through the needle.

[0072] Figure 6(D) is a diagram showing a second liquid injection cap after refilling. In a state where the liquid injection port 130 is covered with the middle cover 1501, the second liquid injection cap 1401 is arranged in such a manner that the second liquid injection cap 1401 covers the joint 143 between the middle cover 1501 and the first liquid injection cap 140. Then, the connecting portion 1431 of the second liquid injection cap 1401 and the cover body 120 are welded. The liquid injection port 130 is sealed by the welding. In addition, in the present embodiment, the hole 170 is formed in the middle cover 1501 using the needle of a syringe, but is not limited to this. It is also possible to insert the needle of a syringe into the hole to inject liquid after forming the hole of the middle cover with a member other than the needle of a syringe. The material of the middle cover 1501 used in the present embodiment is preferably resin or rubber.

[0073] (Fifth Embodiment)

[0074] Figure 7 It is a figure which shows the manufacturing method of the refill liquid of 5th Embodiment. Figure 7 (A) to (D) show the state from before the refilling of the fifth embodiment to the state until the liquid filling port 130 is sealed after the refilling. Figure 7 The steps (A), (B), and (C) are the same as those of the third embodiment.

[0075] Figure 7 (D) is a diagram showing a second liquid filling cap 1401 being provided after refilling. In the second embodiment, the second liquid filling cap 1401 is joined to the container in a state where the middle cover 150 is removed, but in the present embodiment, the middle cover 150 is arranged in such a manner that the middle cover 150 covers the liquid filling port 130 after refilling. Then, the second liquid filling cap 1401 is arranged so that the second liquid filling cap 1401 covers the joint 143 between the middle cover 150 and the first liquid filling cap 140. Then, the connecting portion 1431 of the second liquid filling cap 1401 and the cover body 120 are welded. The liquid filling port 130 is sealed by this welding. By configuring the middle cover 150 again to cover the liquid filling port 130, when the cut-off portion 1421 of the second liquid filling cap 1401 is cut off during the second refilling, the cut-off pieces produced by the cut-off can be prevented from intruding into the container through the liquid filling port 130. In addition, as Figure 7 The middle cover after refilling shown in (D) can be used with Figure 7 The middle cover 150 before refilling shown in (A) may be the same as Figure 7 The middle cover 150 before refilling shown in (A) is different from the middle cover.

[0076] (Sixth Embodiment)

[0077] Figure 8It is a side sectional view schematically showing the middle cover of the sixth embodiment. On the outer surface of the cover body 120, a groove portion 122 matching the peripheral shape of the opening of the middle cover 150 is formed on the outer periphery of the liquid injection port 130. In this case, the end face (opening end) of the opening side of the liquid injection cap 140 is arranged on the groove portion 122 formed on the outer periphery of the liquid injection port 130. The groove portion 122 can also be formed in a circular shape (along the circumference) concentric with the circular liquid injection port 130. A plurality of groove portions 122 are formed in a concentric circle shape, and multiple refills can also be handled. By forming an annular groove portion 122 matching the joint portion 143 of the liquid injection cap 140 on the outer surface of the container 100, the groove portion 122 can be used to easily position the liquid injection cap 140 when it is welded to the outer surface of the container 100. When the storage element 10 is reused, the diameter of the new filling cap 1401 after the refilling becomes larger than the diameter of the filling cap 140 before the refilling. In contrast, by using the groove 122 outside the groove 122 used for the filling cap 140 before the refilling among the plurality of grooves 122 formed as concentric circles, the new filling cap 1401 can be easily positioned after the refilling.

[0078] (Seventh Embodiment)

[0079] Fig. 9 1 is a side cross-sectional view schematically showing the middle cover and the like of the seventh embodiment. As in the first embodiment, the liquid injection cap 140 and the middle cover 1502 of the seventh embodiment are cylindrical. In these liquid injection caps 140 and the middle cover 1502, the cross-sectional area of ​​the cylinder is constant. As in the first embodiment, the liquid injection cap 140 presses the middle cover 150.

[0080] A cylindrical (columnar) protrusion 131 is provided on the outer surface of the cover 120, and a circular through hole is formed in the center of the protrusion 131. The through hole constitutes a liquid injection port 130 for injecting electrolyte. That is, the protrusions 131 form a cylindrical body protruding from the outer surface of the cover 120.

[0081] The middle cover 1502 is configured so that the cylindrical opening faces the liquid injection port 130, and surrounds the cylindrical protrusion 131 from the outer peripheral surface side. The inner diameter of the tube of the middle cover 1502 and the outer diameter of the tube of the protrusion 131 are configured to be approximately the same. The length of the tube of the middle cover 1502 and the height (protrusion length) of the protrusion 131 are configured to be the same. By setting the length and diameter of the middle cover 1502 and the protrusion 131 in this way, the fit between the middle cover 1502 and the protrusion 131 can be improved, making it difficult for the middle cover 1502 to detach from the protrusion 131. As a result, when the liquid injection cap 140 is removed from the container 100, it is possible to further suppress foreign matter from invading the interior of the container 100 from the liquid injection port 130.

[0082] In this embodiment, the inner surface of the bottom plate 141 of the liquid filling cap 140 also contacts or presses the outer surface of the bottom 1512 of the middle cover 1502. As a result, the inner surface of the bottom plate 141 of the liquid filling cap 140 and the top surface of the protrusion 131 sandwich the bottom 1512 of the middle cover 1502. In this way, by sandwiching the middle cover 1502 with the liquid filling cap 140 and the protrusion 131, the positional deviation of the middle cover 1502 can be further suppressed.

[0083] Fig.10 This is a side cross-sectional view schematically showing the middle cap etc. after refilling of the seventh embodiment. In this embodiment, the new filling cap 1401 after refilling uses a filling cap having an opening inner diameter larger than the filling cap 140 before refilling (the filling cap 140 cut off by the cutting portion 142).

[0084] (Other embodiments)

[0085] Regarding the shape of the middle cover, the second embodiment discloses a convex middle cover of the barrel, and the third embodiment discloses a plate-shaped middle cover. However, in the manufacturing method of refilling, the shape of the middle cover is not limited to these shapes. As long as it covers the injection port, it can be any shape.

[0086] The second to fifth embodiments disclose a structure in which the connection portion 1431 of the second liquid filling cap 1401 and the cover body 120 are welded. However, the method of joining the connection portion 1431 of the second liquid filling cap 1401 and the cover body 120 is not limited thereto. For example, an adhesive or the like may be used for joining.

[0087] It should be understood that the embodiments disclosed this time are illustrative in all aspects and not restrictive. The scope of the present invention is not meant to be the above, but is indicated by the claims, and is intended to include all changes within the meaning and scope equivalent to the claims.

[0088] Description of Reference Numerals

[0089] 10 Storage element

[0090] 100 containers

[0091] 110 Container body

[0092] 111 Opening

[0093] 120 cover

[0094] 121 Gas discharge valve

[0095] 122 slot

[0096] 130 liquid injection port

[0097] 131 protrusion

[0098] 132 recess

[0099] 140 filling cap, first filling cap

[0100] 1401 Second filling cap

[0101] 141, 1401 base plate

[0102] 142, 1421 cutting part

[0103] 143Joint

[0104] 1431 Joint (Joint after refilling)

[0105] 150, 1501, 1502 middle cover

[0106] 151, 1512 bottom

[0107] 152 Peripheral

[0108] 160 opening

[0109] 170 holes

[0110] 200 terminals

[0111] 300 Upper Pad

[0112] 400 Insulation member (lower gasket)

[0113] 500 collector

[0114] 600 electrode body

[0115] 610 end

Claims

1. A power storage element, wherein: have: a container having a filling port for injecting electrolyte, a liquid filling cap that seals the liquid filling port from the outside of the container, and A middle cover, located between the liquid injection port and the liquid injection cover, and covering the liquid injection port; The middle cover has insulating properties and is in a shape protruding toward the outside of the container.

2. A method for manufacturing an electric storage element, the electric storage element comprising: a container having an injection port for injecting an electrolyte; a first injection cap for sealing the injection port from the outside of the container; a first middle cap interposed between the injection port and the injection cap and covering the injection port, in, The opening is formed by cutting off a part of the first liquid filling cap, removing the first middle cover through the opening, injecting electrolyte into the container through the opening, The opening is covered with a second liquid filling cap.

3. A method for manufacturing an electric storage element, the electric storage element comprising: a container having an injection port for injecting an electrolyte; a first injection cap for sealing the injection port from the outside of the container; and a middle cap interposed between the injection port and the injection cap to cover the injection port. in, The opening is formed by cutting off a part of the first liquid filling cap, A hole is formed in the middle cover, injecting electrolyte into the container through the opening and the hole, The opening is covered with a second liquid filling cap.

4. The method for manufacturing an electric storage element according to claim 2, wherein: In the step of covering the opening with the second liquid filling cap, the first middle cap or a second middle cap different from the first middle cap is disposed between the second liquid filling cap and the liquid filling port.

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