Energy storage cell

Abstract

An energy storage cell comprises a wound electrode body, a housing, an inner seal (a sealing element), a positive electrode terminal (an external terminal), and a positive electrode connection section (a connecting element). The housing comprises a circumferential wall section, a lower cover (a first cover section), and an upper cover (a second cover section). The lower cover includes a vent valve for releasing gas from the interior of the housing. A through-hole (a second through-hole) is formed in the upper cover (the second cover section). The positive electrode connection section comprises a column-shaped section extending in the Z-direction to penetrate the through-hole of the upper cover and a through-hole (a first through-hole) of the inner seal.The inner seal is positioned so that it covers the through-hole from the inside of the housing.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention

[0001] The present invention relates to an energy storage cell. 2. Description of the state of the art

[0002] WO 2022 / 065 211 A1 discloses a cylindrical battery provided with a can bottom valve that opens when the internal pressure of an outer can becomes too high. SUMMARY OF THE INVENTION

[0003] In a related art energy storage cell, as described in WO 2022 / 065211 A1, an exhaust gas may be discharged (leaked) from a side opposite to a side where a can bottom valve is provided. In this case, the exhaust gas is not efficiently discharged from the can bottom valve (an exhaust valve).

[0004] The present invention provides an energy storage cell that enables efficient removal of exhaust gas from an exhaust valve.

[0005] One aspect of the present invention relates to an energy storage cell comprising a wound electrode body, a casing, a sealing member, an external terminal, and a connecting member. The wound electrode body includes a first electrode and a second electrode. The casing accommodates the wound electrode body. The sealing member is housed in the casing, and a first through-hole is formed in the sealing member. The connecting member electrically connects the external terminal and the first electrode to each other. The casing includes a peripheral wall portion, a first lid portion, and a second lid portion. The peripheral wall portion is disposed radially outside the wound electrode body and extends in a tubular shape along an axial direction of the wound electrode body.The first lid portion closes a first end of the peripheral wall portion in the axial direction. The second lid portion closes a second end of the peripheral wall portion in the axial direction. The first lid portion includes an exhaust valve for discharging a gas from the interior of the housing. A second through-hole is formed in the second lid portion, through which an inside of the housing and an outside of the housing communicate with each other. The connecting member includes a columnar portion extending in the axial direction to penetrate the second through-hole of the second lid portion and the first through-hole of the sealing member. The sealing member is arranged to cover the second through-hole from the inside of the housing.

[0006] In the energy storage cell according to the aspect of the present invention, as described above, the first lid portion is provided with the exhaust valve, and the second through-hole of the second lid portion is covered by the sealing member from the inside of the case. Accordingly, the leakage of an exhaust gas from one side of the second lid portion to the outside of the case is suppressed by the sealing member, the exhaust gas generated from the wound electrode body. As a result, the exhaust gas can be efficiently discharged from the exhaust valve of the first lid portion.

[0007] In the energy storage cell according to the aspect of the present invention, the connecting member may further include a plate-shaped portion connected to the columnar portion inside the casing. The plate-shaped portion may be arranged to extend orthogonally to the axial direction on the side of the sealing member opposite the external terminal. In such a configuration, the plate-shaped portion can be easily arranged to be closer to the inside of the casing (the wound electrode body side) than the sealing member. As a result, the plate-shaped portion and the first electrode inside the casing can be easily electrically connected to each other.

[0008] In this case, the sealing element can be sandwiched between the second cover portion and the plate-shaped portion in the axial direction. With such a configuration, it is possible to suppress the formation of a gap between the sealing element and the second cover portion and the plate-shaped portion. As a result, the escape of exhaust gas from the second cover portion side to the outside of the housing can be suppressed.

[0009] The energy storage cell according to the aspect of the present invention may further include an insulating member arranged to cover the second through-hole of the second lid portion from the outside of the case. The second lid portion may be electrically connected to the second electrode. A third through-hole through which the columnar portion penetrates may be formed in the insulating member, and the insulating member may be arranged to insulate the second lid portion and the external terminal from each other. In such a configuration, the second through-hole is covered by the insulating member, and thus, leakage of the exhaust gas through the second through-hole to the outside of the case can be suppressed.In addition, since the third through-hole is formed in the insulating member, the columnar portion can be inserted into the housing with the second lid portion and the external terminal insulated from each other by the insulating member.

[0010] In this case, the thickness of the sealing element in the axial direction can be greater than the thickness of the insulating element in the axial direction. In this configuration, a gap (space) in the housing can be easily filled with the sealing element, compared to a case where the thickness of the sealing element is equal to or smaller than the thickness of the insulating element. As a result, the leakage of exhaust gas from one side of the sealing element to the outside of the housing can be suppressed.

[0011] According to the aspect of the present invention, it is possible to efficiently discharge an exhaust gas from an exhaust valve provided on a casing of an energy storage cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The features and advantages as well as the technical and economic significance of exemplary embodiments of the invention are described below with reference to the accompanying drawings, in which like reference numerals designate like elements, in which: Fig. 1 is a cross-sectional view showing a configuration of an energy storage cell according to an embodiment; Fig. 2 is a view showing a cross section of an upper lid of the embodiment as seen from a Z1 side; Fig. 3 is a plan view of a lower cover of the embodiment seen from a Z2 side; Fig. 4 is a schematic perspective view showing a configuration of a wound electrode body of the embodiment; Fig. 5 is a plan view showing a configuration of a positive electrode current collector plate of the embodiment; Fig. 6 is a plan view showing a configuration of a negative electrode current collector plate of the embodiment; Fig. 7 is an enlarged partial view showing the vicinity of the positive electrode current collector plate in Fig. 1 shows; Fig. 8 is an enlarged partial view showing the vicinity of the negative electrode current collector plate in Fig. 1 shows; and Fig. 9 is a view showing a cross section of the upper cover of the embodiment as seen from the Z2 side. DETAILED DESCRIPTION OF EMBODIMENTS

[0013] An embodiment of the present invention will be described in detail below with reference to the drawings. Note that in the figures, like or corresponding parts are designated by the same reference numerals, and the description thereof will not be repeated.

[0014] An energy storage cell 100 includes a wound electrode body 1, a casing 2, a positive electrode terminal 3, a positive electrode connecting portion 4, an outer seal 5, an inner seal 6, and a negative electrode current collector plate 7. Both the outer seal 5 and the inner seal 6 have insulating properties. The positive electrode terminal 3 and the inner seal 6 are examples of an "external termination" and a "sealing member" in the present invention, respectively. Furthermore, the outer seal 5 and the positive electrode connecting portion 4 are examples of an "insulating member" and a "connecting member" in the present invention, respectively.

[0015] The wound electrode body 1 is housed in the housing 2. The housing 2 comprises an upper cover 2a, a lower cover 2b, and a peripheral wall portion 2c.

[0016] The peripheral wall portion 2c is arranged radially outside the wound electrode body 1. The peripheral wall portion 2c extends tubularly along an axial direction (a Z direction) of the wound electrode body 1. That is, the casing 2 has a cylindrical shape. The wound electrode body 1 is wound into a cylindrical shape corresponding to the shape of the casing 2. That is, the energy storage cell 100 is a cylindrical battery. The casing 2 is made of copper, aluminum, or the like. In addition, the upper lid 2a and the lower lid 2b are examples of a "second lid portion" and a "first lid portion," respectively, in the present invention. Furthermore, the Z direction is an example of an "axial direction" of the present invention.

[0017] The upper cover 2a closes an opening 2k of the peripheral wall portion 2c located on a Z1 side. Specifically, an outer peripheral edge 2e of the upper cover 2a is welded to an end portion 2d of the peripheral wall portion 2c located on the Z1 side. A welded portion 2f (see hatched part in Fig. 2) between the upper cover 2a and the peripheral wall portion 2c is formed annularly along the outer peripheral edge 2e. The welded portion 2f is formed, for example, by irradiating a portion (near the outer peripheral edge 2e) of the upper cover 2a corresponding to the end portion 2d with a laser from the Z1 side. Note that in Fig. 1, the welded section 2f is not shown for reasons of simplification. Furthermore, the opening 2k is an example of a "second end" within the meaning of the present invention.

[0018] The upper cover 2a is provided with a through hole 2g through which the inside of the housing 2 and the outside of the housing 2 communicate with each other. The through hole 2g is formed in the center of the upper cover 2a. The through hole 2g has a circular shape when viewed from the Z1 side (see Fig. 2). A diameter of the through hole 2g has a length L1 (see Fig. 2). It should be noted that the through hole 2g is an example of a "second through hole" within the meaning of the present invention.

[0019] The lower cover 2b closes an opening 2i of the peripheral wall portion 2c located on a Z2 side. Specifically, an outer peripheral edge 2i of the lower cover 2b is welded to an end portion 2h of the peripheral wall portion 2c located on the Z2 side. A welded portion 2j (see hatched part in Fig. 3) between the lower cover 2b and the peripheral wall portion 2c is formed annularly along the outer peripheral edge 2i. The welded portion 2j is formed, for example, by irradiating a portion (near the outer peripheral edge 2i) of the lower cover 2b corresponding to the end portion 2h with a laser from the Z2 side. Note that in Fig. 1, the welded section 2j is not shown for reasons of simplification. Furthermore, the opening 2I is an example of a "first end" within the meaning of the present invention.

[0020] The lower lid 2b contains an exhaust valve 8 for discharging a gas in the housing 2. The exhaust valve 8 is configured to discharge gas from the housing 2 when the internal pressure of the housing 2 is equal to or higher than a predetermined threshold. The exhaust valve 8 is provided in the center of the lower lid 2b (see Fig. 3).

[0021] The wound electrode body 1 includes a positive electrode sheet 10, a negative electrode sheet 20, and separators 30. Each separator 30 is provided between the positive electrode sheet 10 and the negative electrode sheet 20. The separator 30 allows the movement of ions (e.g., lithium ions) between the positive electrode sheet 10 (an active material for the positive electrode) and the negative electrode sheet 20 (an active material for the negative electrode), and separates the positive electrode sheet 10 and the negative electrode sheet 20 from each other. The wound electrode body 1 is composed of a group of electrode sheets in which the positive electrode sheet 10 and the negative electrode sheet 20 are wound with the separators 30 interposed therebetween. Note that the positive electrode sheet 10 and the negative electrode sheet 20 are examples of a “first electrode” and a “second electrode,” respectively.a “second electrode” within the meaning of the present invention.

[0022] As in Fig. As shown in Figure 4, the positive electrode sheet 10, the negative electrode sheet 20, and the separators 30 of the wound electrode body 1 are wound so as to surround a winding axis α. The wound electrode body 1 is formed by winding the electrode sheets around the winding axis α, wherein the electrode sheets are layered in the order of the negative electrode sheet 20, the separator 30, the positive electrode sheet 10, and the separator 30 from an outer peripheral side. Fig. 4 shows a state in which the wound electrode body 1 is slightly unwound, so that one can easily understand how the wound electrode body 1 is wound.

[0023] Again referring to Fig. 1, the positive electrode terminal 3 is exposed by being provided outside the housing 2. The positive electrode terminal 3 is made of aluminum. The positive electrode terminal 3 is provided on a surface of the outer seal 5 located on the Z1 side, with the outer seal 5 being arranged on the upper cover 2a of the housing 2.

[0024] The positive electrode connecting portion 4 includes a columnar portion 4a and a positive electrode current collecting plate 4b. The columnar portion 4a is connected to the positive electrode terminal 3. The columnar portion 4a extends along the Z direction. The columnar portion 4a connects the positive electrode terminal 3 and the positive electrode current collecting plate 4b to each other. The columnar portion 4a extends from the positive electrode terminal 3 to the inside of the case 2 through the through-hole 2g of the upper cover 2a. The positive electrode current collecting plate 4b is an example of a "plate-shaped portion" of the present invention.

[0025] The positive electrode current collector plate 4b is housed in the casing 2. The positive electrode current collector plate 4b is welded to an end portion 4c of the columnar portion 4a located on the Z2 side.

[0026] The positive electrode current collector plate 4b is arranged to extend so as to intersect (be orthogonal to) the Z direction on the opposite side (the Z2 side) of the inner gasket 6 from the positive electrode terminal 3. Specifically, the positive electrode current collector plate 4b is arranged to be in close contact with a surface of the inner gasket 6 located on the Z2 side.

[0027] The outer seal 5 is arranged outside the housing 2. Specifically, the outer seal 5 is sandwiched between the positive electrode terminal 3 and the upper cover 2a of the housing 2. Accordingly, the positive electrode terminal 3 and the housing 2 (the upper cover 2a) are insulated from each other.

[0028] In the outer seal 5 there is a through hole 5a (see Fig. 7). The columnar portion 4a extends from the positive electrode terminal 3 to the positive electrode current collector plate 4b through the through-hole 5a. The through-hole 5a is an example of a "third through-hole" in the sense of the present invention.

[0029] The inner seal 6 is provided inside the housing 2. Specifically, the inner seal 6 is disposed between the upper cover 2a of the housing 2 and the positive electrode current collector plate 4b. Accordingly, the upper cover 2a of the housing 2 and the positive electrode current collector plate 4b are insulated from each other.

[0030] A through-hole 6a is formed in the inner seal 6. The through-hole 6a is located in the center of the inner seal 6, as viewed along the Z direction.

[0031] The columnar portion 4a extends from the positive electrode terminal 3 to the positive electrode current collector plate 4b through the through hole 6a.

[0032] Furthermore, the inner gasket 6 includes a protruding portion 6b. The protruding portion 6b protrudes from an outer peripheral edge of the inner gasket 6 toward the Z2 side. The protruding portion 6b is provided to shield the positive electrode current collector plate 4b and the peripheral wall portion 2c from each other. Accordingly, the positive electrode current collector plate 4b and the peripheral wall portion 2c are insulated from each other. Note that the through-hole 6a is an example of a "first through-hole" of the present invention.

[0033] The negative electrode current collector plate 7 is housed in the housing 2. The negative electrode current collector plate 7 is welded to an uncoated portion 21b of the negative electrode plate 20, which will be described later. Furthermore, the negative electrode current collector plate 7 is in contact with the bottom cover 2b of the housing 2.

[0034] A through-hole 7a is formed in the negative electrode current collector plate 7. The through-hole 7a is provided at a position where the through-hole 7a overlaps with the exhaust valve 8 in the Z direction. Accordingly, it is possible to easily guide exhaust gas to the exhaust valve 8 through the through-hole 7a.

[0035] Fig. 5 is a plan view of the positive electrode current collector plate 4b. The positive electrode current collector plate 4b has a disc-like shape. The positive electrode current collector plate 4b includes a central portion 4c, spokes 4d, an outer peripheral edge portion 4e, and piece portions 4f.

[0036] The central portion 4c is located at the center of the positive electrode current collection plate 4b. The columnar part 4a is connected to the central portion 4c. The spokes 4d are arranged to extend radially outward from the central portion 4c. Six spokes 4d are arranged at equal angular intervals around the central portion 4c of the positive electrode current collection plate 4b.

[0037] The outer peripheral edge portion 4e is provided at an outer peripheral edge of the positive electrode current collection plate 4b. Each of the six spokes 4d connects the outer peripheral edge portion 4e and the central portion 4c. The spokes 4d are shaped to be bent in the Z direction. The central portion 4c is the portion of the positive electrode current collection plate 4b that moves (displaces) the most in the Z direction.

[0038] A through hole 4g ​​is formed between the spokes 4d, which are adjacent to each other in the circumferential direction. That is, six through holes 4g are formed. The piece portions 4f are respectively provided inside the six through holes 4g. Each of the six piece portions 4f is connected to the outer peripheral edge portion 4e by a connecting portion 4h. Each of the six piece portions 4f is connected to the positive electrode current collection plate 4b by welding. Note that each of the six piece portions 4f has a tapered shape that becomes narrower toward a radially inner side.

[0039] Fig. 6 is a plan view of the negative electrode current collector plate 7. The negative electrode current collector plate 7 has a disc-like shape. The negative electrode current collector plate 7 includes a central portion 7b, spokes 7c, an outer peripheral edge portion 7d, and piece portions 7e.

[0040] The central portion 7b is located at the center of the negative electrode current collector plate 7. The spokes 7c are arranged to extend radially outward from the central portion 7b. The through-hole 7a is located in the central portion 7b. Six spokes 7c are arranged at equal angular intervals around the central portion 7b of the negative electrode current collector plate 7.

[0041] The outer peripheral edge portion 7d is provided at an outer peripheral edge of the negative electrode current collection plate 7. Each of the six spokes 7c connects the outer peripheral edge portion 7d and the central portion 7b. The spokes 7c are shaped to be bent in the Z direction. The outer peripheral edge portion 7d is a portion of the negative electrode current collection plate 7 that moves (displaces) the most in the Z direction.

[0042] A through hole 7f is formed between the spokes 7c, which are adjacent to each other in the circumferential direction. That is, six through holes 7f are formed. The piece portions 7e are respectively provided inside the six through holes 7f. Each of the six piece portions 7e is connected to the outer peripheral edge portion 7d by a connecting portion 7g. Each of the six piece portions 7e is connected to the negative electrode current collection plate 7 by welding. Note that each of the six piece portions 7e has a tapered shape that becomes narrower toward the radially inner side.

[0043] As in Fig. As shown in Figure 7, the positive electrode plate 10 includes a positive electrode current collector 11 and positive electrode mixture layers 12. The positive electrode current collector 11 includes a coated positive electrode portion 11a and an uncoated positive electrode portion 11b. The coated positive electrode portion 11a is a portion of the positive electrode current collector 11 coated with the positive electrode mixture layers 12. The uncoated positive electrode portion 11b is a portion (an exposed portion) of the positive electrode current collector 11 that is not coated with the positive electrode mixture layers 12. Both surfaces of the coated positive electrode portion 11a in the radial direction (R direction) are coated with the positive electrode mixture layers 12.

[0044] The uncoated positive electrode portion 11b is positioned closer to the Z1 side than the coated positive electrode portion 11a. Specifically, the uncoated positive electrode portion 11b protrudes from the coated positive electrode portion 11a toward the Z1 side. The positive electrode mixture layers 12 are in close contact with the separators 30.

[0045] The positive electrode current collector 11 is made of aluminum, for example. The positive electrode mixture layers 12 are formed by coating the surfaces of the positive electrode current collector 11 with a positive electrode slurry and drying the positive electrode slurry. The positive electrode slurry is a slurry prepared by kneading the material (a positive electrode active material, a binder, or the like) of the positive electrode mixture layers 12 and a solvent. The positive electrode mixture layers 12 are in close contact with the separators 30. A thickness t12 of the positive electrode mixture layers 12 is, for example, 0.1 μm or more and 1000 μm or less.

[0046] The uncoated positive electrode portion 11b is bent radially inward when the uncoated positive electrode portion 11b abuts the positive electrode current collector plate 4b located on the Z1 side. The positive electrode current collector plate 4b is positively charged because the positive electrode current collector plate 4b is in contact with the uncoated positive electrode portion 11b. Note that the uncoated positive electrode portion 11b is connected to the positive electrode current collector plate 4b by welding. Accordingly, the positive electrode current collector plate 4b is positively charged. In addition, the positive electrode terminal 3, which is electrically connected to the positive electrode current collector plate 4b through the columnar portion 4a, is positively charged.That is, the positive electrode terminal 3 and the positive electrode plate 10 are electrically connected to each other through the positive electrode connecting portion 4.

[0047] As in Fig. As shown in Figure 8, the negative electrode plate 20 includes a negative electrode current collector 21 and negative electrode mixture layers 22. The negative electrode current collector 21 includes a coated negative electrode portion 21a and an uncoated negative electrode portion 21b. The coated negative electrode portion 21a is a portion of the negative electrode current collector 21 coated with the negative electrode mixture layers 22. The uncoated negative electrode portion 21b is a portion (an exposed portion) of the negative electrode current collector 21 that is not coated with the negative electrode mixture layers 22. Both surfaces of the coated negative electrode portion 21a in the radial direction (the R direction) are coated with the negative electrode mixture layers 22.

[0048] The uncoated negative electrode portion 21b is positioned closer to the Z2 side than the coated negative electrode portion 21a. Specifically, the uncoated negative electrode portion 21b protrudes from the coated negative electrode portion 21a toward the Z2 side. The negative electrode mixture layers 22 are in close contact with the separators 30.

[0049] The negative electrode current collector 21 is made of copper, for example. The negative electrode mixture layers 22 are formed by coating the surfaces of the negative electrode current collector 21 with a negative electrode slurry and drying the negative electrode slurry. The negative electrode slurry is a slurry prepared by kneading the material (a negative electrode active material, a binder, or the like) of the negative electrode mixture layers 22 and a solvent. A thickness t22 of the negative electrode mixture layers 22 is, for example, 0.1 μm or more and 1000 μm or less.

[0050] The uncoated negative electrode portion 21b is bent radially inward when the uncoated negative electrode portion 21b abuts the negative electrode current collector plate 7 located on the Z2 side. The negative electrode current collector plate 7 is negatively charged because the negative electrode current collector plate 7 is in contact with the uncoated negative electrode portion 21b. Accordingly, the lower lid 2b, which is in contact with the negative electrode current collector plate 7, is negatively charged. That is, the negative electrode current collector plate 7 electrically connects the negative electrode sheet 20 and the lower lid 2b of the case 2. In addition, since the lower lid 2b, the peripheral wall portion 2c, and the upper lid 2a are electrically connected, both the peripheral wall portion 2c and the upper lid 2a are negatively charged.

[0051] In the case of a prior art energy storage cell, an exhaust gas may be discharged (leak) from a side opposite to a side where an exhaust valve is provided, and thus the exhaust gas cannot be discharged efficiently from the exhaust valve.

[0052] Therefore, in the present embodiment, as shown in Fig. 7, the inner seal 6 is arranged to cover the through hole 2g from the inside of the housing 2. In particular, the inner seal 6 is arranged to form a gap S (see Fig. 2) formed between the through hole 2g and the columnar portion 4a, viewed from the Z1 side.

[0053] The columnar portion 4a can be press-fitted into the through-hole 6a of the inner seal 6. That is, an outer peripheral surface of the columnar portion 4a and an inner peripheral surface of the through-hole 6a can be in close contact with each other. Accordingly, the through-hole 6a is closed by the columnar portion 4a, and thus exhaust gas can be prevented from escaping to the outside of the housing 2 through the through-hole 6a.

[0054] In addition, the inner seal 6, although not shown, has a disc-like shape when viewed in the Z direction. A diameter of the inner seal 6 has a length L2 (see Fig. 1). In addition, the through hole 6a of the inner seal 6 has a circular shape when viewed along the Z direction (see Fig. 2). A diameter of the through hole 6a has a length L3. Note that the through hole 5a of the outer seal 5 has the same shape as the through hole 6a. That is, a diameter of the through hole 5a has a length L3.

[0055] The inner gasket 6 is sandwiched between the upper cover 2a and the positive electrode current collector plate 4b in the Z direction. That is, as described above, the inner gasket 6 is provided so that a surface of the inner gasket 6 located on the Z2 side is brought into close contact with the positive electrode current collector plate 4b, and a surface of the inner gasket 6 located on the Z1 side is brought into close contact with the upper cover 2a. That is, no gap is formed between the inner gasket 6 and the positive electrode current collector plate 4b and between the inner gasket 6 and the upper cover 2a.

[0056] The inner seal 6 may be formed of an elastic resin or the like. The inner seal 6 can be elastically deformed by being pressed in the Z direction by the upper cover 2a and the positive electrode current collector plate 4b.

[0057] The inner seal 6 has a thickness t1 in the Z direction. Furthermore, the outer seal 5 has a thickness t2 in the Z direction. The minimum thickness t1 of the inner seal 6 is greater than the maximum thickness t2 of the outer seal 5. Furthermore, the minimum thickness t1 of the inner seal 6 is greater than the maximum thickness t3 of the upper cover 2a in the Z direction.

[0058] The outer seal 5 is arranged to cover the through hole 2g of the upper cover 2a from the outside of the housing 2. In particular, the outer seal 5 is arranged to cover the gap S (see Fig.9) formed between the through hole 2g and the columnar portion 4a, viewed from the Z2 side.

[0059] The columnar portion 4a can be press-fitted into the through-hole 5a of the outer seal 5. That is, the outer peripheral surface of the columnar portion 4a and an inner peripheral surface of the through-hole 5a can be in close contact with each other. Accordingly, the through-hole 5a is closed by the columnar portion 4a, and thus exhaust gas can be prevented from escaping from the housing 2 through the through-hole 5a.

[0060] The outer seal 5 has a disc-like shape. A diameter of the outer seal 5 has a length L4. The length L4 is greater than the length L1 of the diameter of the through hole 2g of the upper cover 2a.

[0061] As described above, in the present embodiment, the inner gasket 6 is arranged to cover the through-hole 2g of the upper cover 2a from the inside of the housing 2. Accordingly, the through-hole 2g is blocked by the inner gasket 6 inside the housing 2, and thus exhaust gas can be prevented from escaping from the housing 2 through the through-hole 2g. As a result, the exhaust gas can be efficiently discharged from the exhaust valve 8.

[0062] Moreover, since the housing 2 is formed by means of the upper lid 2a and the lower lid 2b, a manufacturing step and a manufacturing apparatus for the housing 2 can be simplified compared with a case where a housing is formed by drawing up or the like a metal plate.

[0063] In the above-described embodiment, an example was described in which the inner gasket 6 is sandwiched between the upper cover 2a and the positive electrode current collector plate 4b in the Z direction. However, the present invention is not limited to this. For example, a small gap may be formed between the inner gasket 6 and the upper cover 2a.

[0064] In the above-described embodiment, an example was described in which the thickness t1 of the inner seal 6 in the Z direction is greater than the thickness t2 of the outer seal 5 in the Z direction. However, the present invention is not limited to this. The thickness t1 may be equal to or smaller than the thickness t2.

[0065] In the above-described embodiment, an example was described in which the inner gasket (a sealing member) is arranged in close contact with a positive electrode current collector plate (a plate-shaped portion). However, the present invention is not limited to this. The inner gasket (the sealing member) may be arranged so as to be in close contact with the negative electrode current collector plate (a plate-shaped portion).

[0066] In the above-described embodiment, an example was described in which the upper lid 2a and the peripheral wall portion 2c are connected to each other by welding, and the lower lid 2b and the peripheral wall portion 2c are connected to each other by welding. However, the present invention is not limited to this. At least one of the upper lid 2a and the lower lid 2b may be connected to the peripheral wall portion 2c by a rivet.

[0067] The embodiment disclosed herein is to be considered in all respects as exemplary and not restrictive. The scope of the present invention is indicated by the scope of the claims rather than by the description of the above-described embodiment, and is intended to include all changes within the meaning and scope of the claims. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] WO 2022 / 065 211 A1 [0002, 0003]

Claims

[1] Energy storage cell, comprising: a wound electrode body comprising a first electrode and a second electrode; a housing that houses the wound electrode body; a sealing member housed in the housing and having a first through-hole formed therein; an external connection; and a connecting element electrically connecting the external terminal and the first electrode, wherein: the housing includes: a peripheral wall portion disposed radially outside the wound electrode body and extending in a tubular shape along an axial direction of the wound electrode body; a first lid portion closing a first end of the peripheral wall portion in the axial direction; and a second lid portion closing a second end of the peripheral wall portion in the axial direction; the first lid portion has an outlet valve for discharging a gas inside the housing; a second through-hole through which an inside of the housing and an outside of the housing communicate with each other is formed in the second cover portion; the connecting member comprises a columnar portion extending in the axial direction to penetrate the second through-hole of the second cover portion and the first through-hole of the sealing member; and the sealing element is arranged so that it covers the second through-hole from the inside of the housing. [2] Energy storage cell according to claim 1, wherein: the connecting element further comprises a plate-shaped portion connected to the columnar portion inside the housing; and the plate-shaped portion is arranged to extend orthogonally to the axial direction on a side of the sealing member opposite the external terminal. [3] The energy storage cell according to claim 2, wherein the sealing member is sandwiched between the second lid portion and the plate-shaped portion in the axial direction. [4] The energy storage cell according to any one of claims 1 to 3, further comprising an insulating member arranged to cover the second through-hole of the second lid portion from the outside of the case, wherein: the second lid portion is electrically connected to the second electrode; a third through-hole through which the columnar portion penetrates is formed in the insulating member; and the insulating member is arranged to insulate the second cover portion and the external terminal from each other. [5] The energy storage cell according to claim 4, wherein a thickness of the sealing member in the axial direction is greater than a thickness of the insulating member in the axial direction.

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