Energy storage cell

Abstract

To provide a power storage cell capable of exhausting an exhaust gas from an exhaust valve with high efficiency.SOLUTION: A power storage cell 100 comprises: a winding electrode body 1; a case 2; an internal gasket 6 (a seal member); a positive electrode terminal 3 (an external terminal); and a positive electrode connection part 4 (a connection member). The case 2 contains: a peripheral wall part 2c; a lower lid 2b (a first lid part); and an upper lid 2a (a second lid part). The lower lid 2b includes an exhaust valve 8 for exhausting gas in the case 2. In the upper lid 2a (the second lid part), a penetration hole 2g (a second penetration hole) is formed. The positive electrode connection part 4 contains a column-like part 4a that is extended in a Z-direction so as to penetrate the penetration hole 2g of the upper lid 2a and a penetration hole 6a (a first penetration hole) of the internal gasket 6. The internal gasket 6 is arranged so as to cover the penetration hole 2g from an inner side of the case 2.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an energy storage cell. [Background technology]

[0002] International Publication No. 2022 / 065211 (Patent Document 1) discloses a cylindrical battery provided with a can bottom valve that opens when the internal pressure of the outer can increases. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2022 / 065211 Summary of the Invention [Problem to be solved by the invention]

[0004] In conventional energy storage cells such as those described in Patent Document 1, exhaust gas may be discharged (leaked) from the side opposite to the side where the can bottom valve is provided. In this case, the exhaust gas is not efficiently discharged from the can bottom valve (exhaust valve).

[0005] The present disclosure has been made to solve the above-mentioned problems, and an object of the present disclosure is to provide an energy storage cell that can efficiently discharge exhaust gas from an exhaust valve. [Means for solving the problem]

[0006] According to one aspect of the present disclosure, there is provided an energy storage cell including a wound electrode assembly including a first electrode and a second electrode, a case that houses the wound electrode assembly, a seal member housed in the case and having a first through hole formed therein, an external terminal, and a connecting member that electrically connects the external terminal and the first electrode. The case is disposed on the outer periphery of the wound electrode assembly and includes a peripheral wall portion that extends cylindrically along the axial direction of the wound electrode assembly, a first lid portion that closes one axial end of the peripheral wall portion, and a second lid portion that closes the other axial end of the peripheral wall portion. The first lid portion has an exhaust valve for exhausting gas from inside the case. The second lid portion has a second through hole that communicates between the inside and outside of the case. The connecting member includes a columnar portion that extends axially so as to pass through the second through hole of the second lid portion and the first through hole of the seal member. The seal member is disposed so as to cover the second through hole from the inside of the case.

[0007] In the energy storage cell according to one aspect of the present disclosure, as described above, the first lid portion is provided with an exhaust valve, and the second through-hole in the second lid portion is covered by a seal member from the inside of the case. This prevents exhaust gas generated from the wound electrode body from leaking from the second lid portion to the outside of the case. This allows the exhaust gas to be efficiently discharged from the exhaust valve in the first lid portion.

[0008] In the energy storage cell according to the above aspect, the connecting member preferably further includes a plate-shaped portion connected to the columnar portion inside the case. The plate-shaped portion is arranged to extend intersecting the axial direction on the opposite side of the sealing member from the external terminal. With this configuration, the plate-shaped portion can be easily arranged inside the case (on the wound electrode body side) of the sealing member. As a result, the plate-shaped portion and the first electrode can be easily electrically connected inside the case.

[0009] In this case, the sealing member is preferably sandwiched between the second cover and the plate-shaped portion in the axial direction. This configuration can prevent gaps from being formed between the sealing member and the second cover and between the sealing member and the plate-shaped portion. As a result, it is possible to prevent exhaust gas from leaking out of the case from the second cover side.

[0010] The energy storage cell according to the above aspect preferably further includes an insulating member arranged to cover the second through hole of the second lid from the outside of the case. The second lid is electrically connected to the second electrode. The insulating member has a third through hole formed therein through which the columnar portion passes, and is arranged to insulate the second lid from the external terminal. With this configuration, the second through hole is covered by the insulating member, thereby preventing exhaust gas from leaking from the second through hole to the outside of the case. Furthermore, since the third through hole is formed in the insulating member, the columnar portion can be introduced into the inside of the case while insulating the second lid from the external terminal.

[0011] In this case, the axial thickness of the sealing member is greater than the axial thickness of the insulating member. This configuration allows the sealing member to more easily fill gaps (spaces) within the case than when the sealing member is thinner than the insulating member. As a result, it is possible to prevent exhaust gas from leaking out of the case through the sealing member.

[0012] According to the present disclosure, exhaust gas can be efficiently discharged from the exhaust valve provided on the case of the energy storage cell. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a cross-sectional view showing a configuration of a storage cell according to an embodiment. [Figure 2] FIG. 10 is a cross-sectional view of the upper cover according to one embodiment, viewed from the Z1 side. [Figure 3] FIG. 10 is a plan view of the lower cover according to one embodiment, as viewed from the Z2 side. [Figure 4] FIG. 1 is a schematic perspective view showing the configuration of a wound electrode body according to one embodiment. [Figure 5] FIG. 2 is a plan view showing the configuration of a positive electrode current collector plate according to one embodiment. [Figure 6] FIG. 2 is a plan view showing the configuration of a negative electrode current collector plate according to one embodiment. [Figure 7] FIG. 2 is a partially enlarged view of the vicinity of the positive electrode current collector plate in FIG. [Figure 8] FIG. 2 is a partially enlarged view of the vicinity of the negative electrode current collector plate in FIG. [Figure 9] 10 is a cross-sectional view of the upper cover according to an embodiment, viewed from the Z2 side. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals, and description thereof will not be repeated.

[0015] The energy storage cell 100 includes a wound electrode assembly 1, a case 2, a positive electrode terminal 3, a positive electrode connection portion 4, an external gasket 5, an internal gasket 6, and a negative electrode current collector plate 7. The external gasket 5 and the internal gasket 6 are each insulating. The positive electrode terminal 3 and the internal gasket 6 are examples of the "external terminal" and the "sealing member" of the present disclosure, respectively. The external gasket 5 and the positive electrode connection portion 4 are examples of the "insulating member" and the "connecting member" of the present disclosure, respectively.

[0016] The wound electrode body 1 is housed in a case 2. The case 2 includes an upper lid 2a, a lower lid 2b, and a peripheral wall portion 2c. The peripheral wall portion 2c is arranged on the outer periphery of the wound electrode body 1. The peripheral wall portion 2c extends in a cylindrical shape along the axial direction (Z direction) of the wound electrode body 1. That is, the case 2 has a cylindrical shape. The wound electrode body 1 is wound so as to have a cylindrical shape like the case 2. That is, the energy storage cell 100 is a cylindrical battery. The case 2 is made of copper, aluminum, or the like. The upper lid 2a and the lower lid 2b are examples of the "second lid portion" and the "first lid portion" of the present disclosure, respectively. The Z direction is an example of the "axial direction" of the present disclosure.

[0017] The top cover 2a closes an opening 2k on the Z1 side of the peripheral wall portion 2c. Specifically, an outer peripheral edge 2e of the top cover 2a is welded to an end 2d on the Z1 side of the peripheral wall portion 2c. A weld 2f (see the hatched portion in FIG. 2) between the top cover 2a and the peripheral wall portion 2c is formed in a ring shape along the outer peripheral edge 2e. The weld 2f is formed, for example, by irradiating a laser from the Z1 side toward a portion of the top cover 2a corresponding to the end 2d (near the outer peripheral edge 2e). For simplicity, the weld 2f is not shown in FIG. 1. The opening 2k is an example of the "other end" of the present disclosure.

[0018] The top cover 2a has a through hole 2g formed therein that connects the inside and outside of the case 2. The through hole 2g is formed in the center of the top cover 2a. The through hole 2g has a circular shape when viewed from the Z1 side (see FIG. 2). The diameter of the through hole 2g has a length L1 (see FIG. 2). The through hole 2g is an example of a "second through hole" in the present disclosure.

[0019] The bottom cover 2b closes an opening 2l on the Z2 side of the peripheral wall 2c. Specifically, an outer peripheral edge 2i of the bottom cover 2b is welded to an end 2h on the Z2 side of the peripheral wall 2c. As a result, a welded portion 2j (see the hatched portion in FIG. 3) between the bottom cover 2b and the peripheral wall 2c is formed in an annular shape along the outer peripheral edge 2i. The welded portion 2j is formed, for example, by irradiating a laser from the Z2 side toward a portion of the bottom cover 2b corresponding to the end 2h (near the outer peripheral edge 2i). For simplicity, the welded portion 2j is not shown in FIG. 1. The opening 2l is an example of "one end" in the present disclosure.

[0020] The bottom lid 2b has an exhaust valve 8 for exhausting gas inside the case 2. The exhaust valve 8 is configured to exhaust gas from the case 2 when the internal pressure of the case 2 reaches or exceeds a predetermined threshold. The exhaust valve 8 is provided in the center of the bottom lid 2b (see FIG. 3).

[0021] The wound electrode body 1 includes a positive electrode sheet 10, a negative electrode sheet 20, and a separator 30. The separator 30 is provided between the positive electrode sheet 10 and the negative electrode sheet 20. The separator 30 separates the positive electrode sheet 10 and the negative electrode sheet 20 while allowing ions (e.g., lithium ions) to move between the positive electrode sheet 10 (positive electrode active material) and the negative electrode sheet 20 (negative electrode active material). The wound electrode body 1 is composed of an electrode plate assembly in which the positive electrode sheet 10 and the negative electrode sheet 20 are wound with the separator 30 interposed therebetween. The positive electrode sheet 10 and the negative electrode sheet 20 are examples of the "first electrode" and the "second electrode," respectively, of the present disclosure.

[0022] As shown in Fig. 4, the wound electrode body 1 has a positive electrode sheet 10, a negative electrode sheet 20, and a separator 30 wound around the winding axis α. The wound electrode body 1 is formed by winding electrode sheets stacked in the order of negative electrode sheet 20, separator 30, positive electrode sheet 10, and separator 30 from the outer periphery around the winding axis α. Fig. 4 shows the wound electrode body 1 in a slightly unwound state so that the wound state of the wound electrode body 1 can be easily seen.

[0023] 1, the positive electrode terminal 3 is exposed by being disposed outside the case 2. The positive electrode terminal 3 is made of aluminum. The positive electrode terminal 3 is disposed on the surface of the Z1 side of the external gasket 5 disposed on the top lid 2a of the case 2.

[0024] The positive electrode connection part 4 includes a columnar portion 4a and a positive electrode current collector plate 4b. The columnar portion 4a is connected to the positive electrode terminal 3. The columnar portion 4a is provided to extend along the Z direction. The columnar portion 4a connects the positive electrode terminal 3 and the positive electrode current collector plate 4b. The columnar portion 4a extends from the positive electrode terminal 3 through the through-hole 2g in the upper lid 2a to the inside of the case 2. The positive electrode current collector plate 4b is an example of a "plate-shaped portion" in the present disclosure.

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

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

[0027] The external gasket 5 is provided on the outside of the case 2. Specifically, the external gasket 5 is sandwiched between the positive electrode terminal 3 and the upper lid 2a of the case 2. This insulates the positive electrode terminal 3 from the case 2 (upper lid 2a).

[0028] A through hole 5a (see FIG. 7) is formed in the outer gasket 5. The columnar portion 4a extends from the positive electrode terminal 3 through the through hole 5a to the positive electrode current collector plate 4b. The through hole 5a is an example of a "third through hole" of the present disclosure.

[0029] The internal gasket 6 is provided inside the case 2. Specifically, the internal gasket 6 is disposed between the upper lid 2a of the case 2 and the positive current collector plate 4b. This insulates the upper lid 2a of the case 2 from the positive current collector plate 4b.

[0030] A through hole 6a is formed in the internal gasket 6. When viewed along the Z direction, the through hole 6a is provided in the center of the internal gasket 6. The columnar portion 4a extends from the positive electrode terminal 3 through the through hole 6a to the positive electrode current collector plate 4b.

[0031] The internal gasket 6 also includes a protrusion 6b. The protrusion 6b protrudes from the outer periphery of the internal gasket 6 toward the Z2 side. The protrusion 6b is provided to shield the positive current collector 4b from the peripheral wall 2c. This insulates the positive current collector 4b from the peripheral wall 2c. The through hole 6a is an example of a "first through hole" in the present disclosure.

[0032] The negative electrode current collector 7 is housed in the case 2. The negative electrode current collector 7 is welded to a negative electrode uncoated portion 21b (described later) of the negative electrode sheet 20. The negative electrode current collector 7 also contacts the bottom lid 2b of the case 2.

[0033] A through hole 7a is formed in the negative electrode current collector plate 7. The through hole 7a is provided at a position overlapping with the exhaust valve 8 in the Z direction. This allows exhaust gas to be easily guided to the exhaust valve 8 through the through hole 7a.

[0034] 5 is a plan view of the positive current collector 4b. The positive current collector 4b has a disk shape and includes a central portion 4c, spokes 4d, an outer peripheral edge portion 4e, and a piece portion 4f.

[0035] The central portion 4c is provided at the center of the positive current collector plate 4b. The columnar portions 4a are joined to the central portion 4c. The spokes 4d are provided so as to extend radially outward from the central portion 4c. Six spokes 4d are provided at equal angular intervals around the central portion 4c of the positive current collector plate 4b.

[0036] The outer peripheral edge portion 4e is provided on the outer peripheral edge of the positive current collector plate 4b. Each of the six spokes 4d connects the outer peripheral edge portion 4e and the central portion 4c. The spokes 4d are formed to bend in the Z direction. Note that the central portion 4c of the positive current collector plate 4b moves (displaces) the most in the Z direction.

[0037] Between the circumferentially adjacent spokes 4d, a through hole 4g ​​is formed. That is, six through holes 4g are formed. A piece 4f is provided inside each of the six through holes 4g. Each of the six pieces 4f is connected to the outer peripheral edge portion 4e by a connecting portion 4h. Each of the six pieces 4f is joined to the positive electrode current collector plate 4b by welding. Each of the six pieces 4f has a shape that tapers radially inward.

[0038] 6 is a plan view of the negative electrode current collector 7. The negative electrode current collector 7 has a disk shape and includes a central portion 7b, spokes 7c, an outer peripheral edge portion 7d, and a piece portion 7e.

[0039] The central portion 7b is provided at the center of the negative electrode current collector 7. The spokes 7c are provided to extend radially outward from the central portion 7b. The through holes 7a are provided in the central portion 7b. Six spokes 7c are provided at equal angular intervals around the central portion 7b of the negative electrode current collector 7.

[0040] The outer peripheral edge portion 7d is provided on the outer peripheral edge of the negative electrode current collector plate 7. Each of the six spokes 7c connects the outer peripheral edge portion 7d and the central portion 7b. Each spoke 7c is formed to bend in the Z direction. The outer peripheral edge portion 7d of the negative electrode current collector plate 7 moves (displaces) the most in the Z direction.

[0041] Between the circumferentially adjacent spokes 7c, a through hole 7f is formed. That is, six through holes 7f are formed. A piece 7e is provided inside each of the six through holes 7f. Each of the six pieces 7e is connected to the outer peripheral edge portion 7d by a connecting portion 7g. Each of the six pieces 7e is joined to the negative electrode current collector plate 7 by welding. Each of the six pieces 7e has a shape that tapers radially inward.

[0042] As shown in FIG. 7, the positive electrode sheet 10 includes a positive electrode current collector 11 and a positive electrode composite layer 12. The positive electrode current collector 11 has a positive electrode coated portion 11a and a positive electrode uncoated portion 11b. The positive electrode coated portion 11a is a portion of the positive electrode current collector 11 that is coated with the positive electrode composite layer 12. The positive electrode uncoated portion 11b is a portion of the positive electrode current collector 11 that is not coated with the positive electrode composite layer 12 (exposed portion). The positive electrode composite layer 12 is coated on both radial (R) surfaces of the positive electrode coated portion 11a.

[0043] Positive electrode uncoated portion 11b is located closer to Z1 than positive electrode coated portion 11a. Specifically, positive electrode uncoated portion 11b protrudes from positive electrode coated portion 11a to the Z1 side. Positive electrode mixture layer 12 is in close contact with separator 30.

[0044] Positive electrode current collector 11 is made of, for example, aluminum. Positive electrode mixture layer 12 is formed by applying a positive electrode slurry to the surface of positive electrode current collector 11 and drying it. The positive electrode slurry is prepared by kneading materials for positive electrode mixture layer 12 (such as a positive electrode active material and a binder) with a solvent. Positive electrode mixture layer 12 is in close contact with separator 30. Positive electrode mixture layer 12 has a thickness t12 of, for example, 0.1 μm or more and 1000 μm or less.

[0045] The positive electrode uncoated portion 11b is bent radially inward by contact with the positive electrode current collector 4b arranged on the Z1 side. The positive electrode current collector 4b is positively charged due to contact with the positive electrode uncoated portion 11b. The positive electrode uncoated portion 11b is joined to the positive electrode current collector 4b by welding. This causes the positive electrode current collector 4b to be positively charged. Furthermore, the positive electrode terminal 3, which is electrically connected to the positive electrode current collector 4b by the columnar portion 4a, is positively charged. In other words, the positive electrode terminal 3 and the positive electrode sheet 10 are electrically connected by the positive electrode connection portion 4.

[0046] As shown in FIG. 8, the negative electrode sheet 20 includes a negative electrode current collector 21 and a negative electrode composite material layer 22. The negative electrode current collector 21 has a negative electrode coated portion 21a and a negative electrode uncoated portion 21b. The negative electrode coated portion 21a is a portion of the negative electrode current collector 21 that is coated with the negative electrode composite material layer 22. The negative electrode uncoated portion 21b is a portion (exposed portion) of the negative electrode current collector 21 that is not coated with the negative electrode composite material layer 22. The negative electrode composite material layer 22 is coated on both radial (R) surfaces of the negative electrode coated portion 21a.

[0047] Negative electrode uncoated portion 21b is located closer to Z2 side than negative electrode coated portion 21a. Specifically, negative electrode uncoated portion 21b protrudes from negative electrode coated portion 21a to the Z2 side. Negative electrode composite layer 22 is in close contact with separator 30.

[0048] Negative electrode current collector 21 is made of, for example, copper. Negative electrode mixture layer 22 is formed by applying a negative electrode slurry to the surface of negative electrode current collector 21 and drying the coating. The negative electrode slurry is prepared by kneading materials for negative electrode mixture layer 22 (negative electrode active material, binder, etc.) with a solvent. Negative electrode mixture layer 22 has a thickness t22 of, for example, 0.1 μm or more and 1000 μm or less.

[0049] The negative electrode uncoated portion 21b is bent radially inward by contact with the negative electrode current collector 7 arranged on the Z2 side. The negative electrode current collector 7 is negatively charged by contact with the negative electrode uncoated portion 21b. As a result, the bottom lid 2b in contact with the negative electrode current collector 7 is negatively charged. In other words, the negative electrode current collector 7 electrically connects the negative electrode sheet 20 and the bottom lid 2b of the case 2. Furthermore, the bottom lid 2b, the peripheral wall 2c, and the top lid 2a are electrically connected, and therefore the peripheral wall 2c and the top lid 2a are each negatively charged.

[0050] Here, in a conventional energy storage cell, exhaust gas may be discharged (leaked) from the side opposite to the side where the exhaust valve is provided, and therefore the exhaust gas may not be discharged efficiently from the exhaust valve.

[0051] 7, in this embodiment, the internal gasket 6 is arranged to cover the through hole 2g from the inside of the case 2. Specifically, the internal gasket 6 is arranged to fill the gap S (see FIG. 2) formed between the through hole 2g and the columnar portion 4a when viewed from the Z1 side.

[0052] The columnar portion 4a may be press-fitted into the through-hole 6a of the internal gasket 6. That is, the outer peripheral surface of the columnar portion 4a may be in close contact with the inner peripheral surface of the through-hole 6a. This allows the columnar portion 4a to plug the through-hole 6a, thereby preventing exhaust gas from being discharged to the outside of the case 2 through the through-hole 6a.

[0053] Although not shown, the internal gasket 6 has a disk shape when viewed along the Z direction. The diameter of the internal gasket 6 has a length L2 (see FIG. 1). The through hole 6a of the internal gasket 6 has a circular shape when viewed along the Z direction (see FIG. 2). The diameter of the through hole 6a has a length L3. The through hole 5a of the external gasket 5 has the same shape as the through hole 6a. That is, the diameter of the through hole 5a has a length L3.

[0054] The internal gasket 6 is sandwiched between the upper lid 2a and the positive current collector 4b in the Z direction. That is, the internal gasket 6 is provided so that the Z2-side surface of the internal gasket 6 is in close contact with the positive current collector 4b as described above, and also so that the Z1-side surface of the internal gasket 6 is in close contact with the upper lid 2a. That is, no gap is formed between the internal gasket 6 and the positive current collector 4b, and between the internal gasket 6 and the upper lid 2a.

[0055] The internal gasket 6 may be made of an elastic resin or the like. The internal gasket 6 may be elastically deformed by being pressed in the Z direction by the upper cover 2a and the positive electrode current collector plate 4b.

[0056] The internal gasket 6 has a thickness t1 in the Z direction. The external gasket 5 has a thickness t2 in the Z direction. The minimum value of the thickness t1 of the internal gasket 6 is greater than the maximum value of the thickness t2 of the external gasket 5. Furthermore, the minimum value of the thickness t1 of the internal gasket 6 is greater than the maximum value of the thickness t3 in the Z direction of the top cover 2a.

[0057] The external gasket 5 is arranged to cover the through-hole 2g of the upper cover 2a from the outside of the case 2. Specifically, the external gasket 5 is arranged to fill the gap S (see FIG. 9) formed between the through-hole 2g and the columnar portion 4a when viewed from the Z2 side.

[0058] The columnar portion 4a may be press-fitted into the through hole 5a of the outer gasket 5. That is, the outer peripheral surface of the columnar portion 4a may be in close contact with the inner peripheral surface of the through hole 5a. This allows the columnar portion 4a to plug the through hole 5a, thereby preventing exhaust gas from being discharged to the outside of the case 2 through the through hole 5a.

[0059] The outer gasket 5 has a disk shape. The outer gasket 5 has a diameter of length L4. Length L4 is greater than length L1, which is the diameter of the through-hole 2g of the upper cover 2a.

[0060] As described above, in this embodiment, the internal gasket 6 is disposed so as to cover the through-hole 2g of the upper lid 2a from the inside of the case 2. This causes the through-hole 2g to be blocked by the internal gasket 6 inside the case 2, thereby preventing exhaust gas from leaking from the through-hole 2g to the outside of the case 2. As a result, the exhaust gas can be efficiently discharged from the exhaust valve 8.

[0061] Furthermore, compared to forming a case by drawing a metal plate, by forming the case 2 using the upper cover 2a and the lower cover 2b, the manufacturing process and manufacturing equipment for the case 2 can be simplified.

[0062] In the above embodiment, the internal gasket 6 is sandwiched between the upper cover 2a and the positive electrode current collector plate 4b in the Z direction, but the present disclosure is not limited to this. For example, a small gap may be formed between the internal gasket 6 and the upper cover 2a.

[0063] In the above embodiment, an example was shown in which the thickness t1 of the inner gasket 6 in the Z direction is greater than the thickness t2 of the outer gasket 5 in the Z direction, but the present disclosure is not limited to this. The thickness t1 may be equal to or less than the thickness t2.

[0064] In the above embodiment, an example was shown in which the internal gasket (sealing member) was provided in close contact with the positive electrode current collector plate (plate-shaped portion), but the present disclosure is not limited to this. The internal gasket (sealing member) may also be provided in close contact with the negative electrode current collector plate (plate-shaped portion).

[0065] In the above embodiment, the upper cover 2a and the peripheral wall 2c, and the lower cover 2b and the peripheral wall 2c are respectively joined by welding, but the present disclosure is not limited to this. At least one of the above may be connected by crimping.

[0066] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is defined by the claims, not by the description of the above embodiments, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0067] 1 wound electrode body, 2 case, 2a upper cover (second cover portion), 2b lower cover (first cover portion), 2c peripheral wall portion, 2g through hole (second through hole), 2k opening (other end), 2l opening (one end), 3 positive electrode terminal (external terminal), 4 positive electrode connection portion (connection member), 4a columnar portion, 4b positive electrode current collector plate (plate-shaped portion), 5 external gasket (insulating member), 5a through hole (third through hole), 6 internal gasket (sealing member), 6a through hole (first through hole), 8 exhaust valve, 10 positive electrode sheet (first electrode), 20 negative electrode sheet (second electrode), 100 storage cell, t1 thickness (thickness of internal gasket), t2 thickness (thickness of external gasket), Z direction (axial direction).

Claims

1. a wound electrode body including a first electrode and a second electrode; a case that houses the wound electrode body; a seal member housed in the case and having a first through hole formed therein; An external terminal, a connection member that electrically connects the external terminal and the first electrode, The case is a peripheral wall portion disposed on an outer circumferential side of the wound electrode body and extending in a cylindrical shape along the axial direction of the wound electrode body; a first cover portion that closes one end of the peripheral wall portion in the axial direction; a second cover portion that closes the other end of the peripheral wall portion in the axial direction, the first lid portion has an exhaust valve for exhausting gas inside the case, The second cover portion has a second through hole formed therein that communicates the inside and the outside of the case, the connecting member includes a columnar portion extending in the axial direction to pass through the second through hole of the second lid portion and the first through hole of the sealing member, the sealing member is disposed to cover the second through hole from the inside of the case, The inner peripheral surface of the second through hole and the outer peripheral surface of the columnar portion face each other without being shielded by a shield, thereby forming a gap between them.

2. the connecting member further includes a plate-like portion connected to the column-like portion inside the case, The energy storage cell according to claim 1 , wherein the plate-shaped portion is disposed on an opposite side of the sealing member from the external terminal, and extends intersecting the axial direction.

3. The sealing member includes a flat portion extending intersecting the axial direction and a protruding portion protruding from the outer peripheral edge of the flat portion to the side opposite the second lid portion, the protrusion is provided to shield an outer peripheral edge of the plate-shaped portion from the peripheral wall portion, The energy storage cell according to claim 2 , wherein a thickness of the protruding portion in the radial direction of the wound electrode body is smaller than a thickness of the flat portion in the axial direction.

4. The energy storage cell according to claim 2 or 3, wherein the sealing member is sandwiched between the second lid portion and the plate-shaped portion in the axial direction.

5. an insulating member disposed so as to cover the second through-hole of the second lid portion from the outside of the case; the second lid portion is electrically connected to the second electrode, The insulating member is a third through hole through which the columnar portion passes is formed; The energy storage cell according to any one of claims 1 to 3, wherein the second lid portion and the external terminal are arranged so as to be insulated from each other.

6. The energy storage cell according to claim 5 , wherein a thickness of the sealing member in the axial direction is greater than a thickness of the insulating member in the axial direction.

7. A storage cell described in any one of claims 1 to 3, wherein the sealing member is positioned so as to fill the gap when viewing the second through hole from a position spaced apart from the second through hole in the axial direction.

8. A storage cell described in any one of claims 1 to 3, wherein the gap is formed in a circular ring shape when viewing the second through hole from a position spaced apart from the second through hole in the axial direction.

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