Electricity storage unit

Abstract

The present disclosure relates to a power storage unit. An electricity storage unit is provided with a wound electrode body, a case, an inner gasket (sealing member), a positive electrode terminal (external terminal), and a positive electrode connecting part (connecting member). The housing includes a peripheral wall portion, a lower cover (a first cover portion), and an upper cover (a second cover portion). The lower cover has an exhaust valve for exhausting gas within the housing. A through hole (second through hole) is formed in the upper cover (second cover part). The positive electrode connection portion includes a columnar portion extending in the Z direction so as to penetrate through the through-hole of the upper cover and the through-hole (first through-hole) of the inner gasket. The inner gasket is disposed so as to cover the through-hole from the inside of the housing.

Description

Technical Field

[0001] The present disclosure relates to a power storage unit. Background Art

[0002] A cylindrical battery provided with a bottom valve that opens when the internal pressure of an outer can increases is disclosed in International Publication No. 2022 / 065211. SUMMARY OF THE INVENTION

[0003] In the conventional power storage unit described in the above International Publication No. 2022 / 065211, exhaust gas may be discharged (leaked) from the side opposite to the side where the bottom valve is provided. In this case, the exhaust gas is not efficiently discharged from the bottom valve (exhaust valve).

[0004] The present disclosure has been completed to solve the above problems, and an object thereof is to provide a power storage unit capable of efficiently discharging exhaust gas from an exhaust valve.

[0005] A power storage unit according to an aspect of the present disclosure includes:

[0006] A wound electrode body including a first electrode and a second electrode;

[0007] A housing that houses the wound electrode body;

[0008] A sealing member that is housed in the housing and has a first through hole formed therein;

[0009] An external terminal; and

[0010] A connection member that electrically connects the external terminal and the first electrode.

[0011] The housing includes:

[0012] A peripheral wall portion that is disposed on the outer peripheral side of the wound electrode body and extends in a cylindrical shape along the axial direction of the wound electrode body;

[0013] A first lid portion that closes one axial end of the peripheral wall portion; and

[0014] A second lid portion that closes the other axial end of the peripheral wall portion.

[0015] The first lid portion has an exhaust valve for discharging gas inside the housing.

[0016] The second lid portion has a second through hole that communicates the inside and outside of the housing.

[0017] The connection member includes a columnar portion that extends in the axial direction so as to penetrate the second through hole of the second lid portion and the first through hole of the sealing member.

[0018] The sealing member is disposed so as to cover the second through hole from the inside of the housing.

[0019] In the power storage unit according to one aspect of the present disclosure, as described above, an exhaust valve is provided in the first lid portion, and the second through-hole of the second lid portion is covered from the inside of the housing by a sealing member. Thus, leakage of exhaust gas generated from the wound electrode body to the outside of the housing from the second lid portion side is suppressed by the sealing member. Thereby, the exhaust gas can be efficiently discharged from the exhaust valve of the first lid portion.

[0020] In the power storage unit according to the above aspect, preferably,

[0021] The connecting member further includes a plate-like portion connected to the columnar portion inside the housing.

[0022] The plate-like portion is disposed on the side opposite to the external terminal with respect to the sealing member so as to extend crossing the axial direction.

[0023] If configured in this way, the plate-like portion can be easily disposed on the inner side of the housing (wound electrode body side) relative to the sealing member. As a result, the plate-like portion and the first electrode can be easily electrically connected inside the housing.

[0024] In this case, preferably,

[0025] The sealing member is sandwiched axially by the second lid portion and the plate-like portion.

[0026] If configured in this way, formation of a gap between the sealing member and each of the second lid portion and the plate-like portion can be suppressed. As a result, leakage of exhaust gas from the second lid portion side to the outside of the housing can be suppressed.

[0027] In the power storage unit according to the above aspect, preferably,

[0028] It further includes an insulating member disposed so as to cover the second through-hole of the second lid portion from the outside of the housing.

[0029] The second lid portion is electrically connected to the second electrode.

[0030] The insulating member is formed with a third through-hole through which the columnar portion passes, and is disposed so as to insulate the second lid portion and the external terminal.

[0031] If configured in this way, since the second through-hole is covered by the insulating member, leakage of exhaust gas from the second through-hole to the outside of the housing can be suppressed. In addition, by forming the third through-hole in the insulating member, the columnar portion can be introduced into the housing while insulating the second lid portion and the external terminal by the insulating member.

[0032] In this case,

[0033] The thickness of the sealing member in the axial direction is larger than the thickness of the insulating member in the axial direction.

[0034] With such a configuration, compared with the case where the thickness of the sealing member is equal to or less than the thickness of the insulating member, the gap (space) inside the housing can be easily filled with the sealing member. As a result, leakage of exhaust gas from the side of the sealing member to the outside of the housing can be suppressed.

[0035] According to the present disclosure, exhaust gas can be efficiently discharged from the exhaust valve provided in the housing of the power storage unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Features, advantages, and technical and industrial significance of exemplary embodiments of the present utility model will be described below with reference to the accompanying drawings, in which like reference numerals denote like elements.

[0037] Figure 1 is a cross-sectional view showing the configuration of a power storage unit according to an embodiment;

[0038] Figure 2 is a view of a cross-section of an upper lid according to an embodiment as viewed from the Z1 side;

[0039] Figure 3 is a plan view of a lower lid according to an embodiment as viewed from the Z2 side;

[0040] Figure 4 is a schematic perspective view showing the configuration of a wound electrode body according to an embodiment;

[0041] Figure 5 is a plan view showing the configuration of a positive current collector according to an embodiment;

[0042] Figure 6 is a plan view showing the configuration of a negative current collector according to an embodiment;

[0043] Figure 7 is Figure 1 a partially enlarged view of the vicinity of the positive current collector of

[0044] Figure 8 is Figure 1 a partially enlarged view of the vicinity of the negative current collector of

[0045] Figure 9 is a view of a cross-section of an upper lid according to an embodiment as viewed from the Z2 side. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0046] Hereinafter, embodiments of the present disclosure will be described in detail while referring to the attached Figure 1 drawings. In addition, the same or corresponding parts in the drawings are denoted by the same reference numerals, and their description will not be repeated.

[0047] The power storage unit 100 includes a wound electrode body 1, a housing 2, a positive 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. In addition, the positive terminal 3 and the internal gasket 6 are each an example of the "external terminal" and the "sealing member" of the present disclosure. Further, the external gasket 5 and the positive electrode connection portion 4 are each an example of the "insulating member" and the "connection member" of the present disclosure.

[0048] The wound electrode body 1 is housed in the housing 2. The housing 2 includes an upper lid 2a, a lower lid 2b, and a peripheral wall portion 2c. The peripheral wall portion 2c is disposed on the outer peripheral side 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 housing 2 has a cylindrical shape. The wound electrode body 1 is wound in such a manner as to have the same cylindrical shape as the housing 2. That is, the power storage unit 100 is a cylindrical battery. In addition, the housing 2 is formed of copper or aluminum or the like. Further, the upper lid 2a and the lower lid 2b are each an example of the "second lid portion" and the "first lid portion" of the present disclosure. Further, the Z direction is an example of the "axial direction" of the present disclosure.

[0049] The upper lid 2a closes the opening 2k on the Z1 side of the peripheral wall portion 2c. Specifically, the outer peripheral edge 2e of the upper lid 2a is welded to the end portion 2d on the Z1 side of the peripheral wall portion 2c. The welded portion 2f (refer to Figure 2 the diagonal portion) of the upper lid 2a and the peripheral wall portion 2c is formed in a circular shape 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 lid 2a corresponding to the end portion 2d with laser light from the Z1 side. In addition, in Figure 1 , for simplicity, the illustration of the welded portion 2f is omitted. Further, the opening 2k is an example of the "other end" of the present disclosure.

[0050] The upper lid 2a is formed with a through hole 2g that communicates the inside and the outside of the housing 2. The through hole 2g is formed at the center of the upper lid 2a. The through hole 2g has a circular shape when viewed from the Z1 side (refer to Figure 2 ). The diameter of the through hole 2g has a length L1 (refer to Figure 2 ). In addition, the through hole 2g is an example of the "second through hole" of the present disclosure.

[0051] The lower lid 2b closes the opening 2l on the Z2 side in the peripheral wall portion 2c. Specifically, the outer peripheral edge 2i of the lower lid 2b is welded to the end portion 2h on the Z2 side of the peripheral wall portion 2c. Thereby, the welded portion 2j (refer to Figure 3 the diagonal portion) of the lower lid 2b and the peripheral wall portion 2c is formed in a circular shape 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 lid 2b corresponding to the end portion 2h with laser light from the Z2 side. In addition, in Figure 1In the figure, for simplicity, the illustration of the welded portion 2j is omitted. In addition, the opening 2l is an example of the "one end" of the present disclosure.

[0052] The lower cover 2b has an exhaust valve 8 for discharging the gas inside the housing 2. The exhaust valve 8 is configured to discharge the gas from the housing 2 when the internal pressure of the housing 2 becomes equal to or higher than a predetermined threshold value. The exhaust valve 8 is provided at the center of the lower cover 2b (see Figure 3 ).

[0053] 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 allows ions (e.g., lithium ions) to move back and forth between the positive electrode sheet 10 (positive electrode active material) and the negative electrode sheet 20 (negative electrode active material) and separates the positive electrode sheet 10 and the negative electrode sheet 20. The wound electrode body 1 is composed of a plate group obtained by winding the positive electrode sheet 10 and the negative electrode sheet 20 with the separator 30 interposed therebetween. In addition, the positive electrode sheet 10 and the negative electrode sheet 20 are examples of the "first electrode" and the "second electrode" of the present disclosure, respectively.

[0054] As Figure 4 shown, the wound electrode body 1 is wound in such a manner that the positive electrode sheet 10, the negative electrode sheet 20, and the separator 30 surround the periphery of the winding axis α. The wound electrode body 1 is formed by winding an electrode sheet obtained by laminating the negative electrode sheet 20, the separator 30, the positive electrode sheet 10, and the separator 30 in this order from the outer peripheral side around the winding axis α. In Figure 4 order to make the winding state of the wound electrode body 1 easily understandable, a state in which the winding of the wound electrode body 1 is slightly loosened is illustrated.

[0055] Referring again to Figure 1 , the positive terminal 3 is exposed by being provided outside the housing 2. The positive terminal 3 is formed of aluminum. The positive terminal 3 is provided on the surface on the Z1 side of the external gasket 5 disposed on the upper cover 2a of the housing 2.

[0056] The positive electrode connection portion 4 includes a columnar portion 4a and a positive electrode current collector plate 4b. The columnar portion 4a is connected to the positive terminal 3. The columnar portion 4a is provided so as to extend along the Z direction. The columnar portion 4a connects the positive terminal 3 and the positive electrode current collector plate 4b. The columnar portion 4a extends from the positive terminal 3 through the through hole 2g of the upper cover 2a to the inside of the housing 2. In addition, the positive electrode current collector plate 4b is an example of the "plate-like portion" of the present disclosure.

[0057] The positive electrode current collector plate 4b is housed in the housing 2. The positive electrode current collector plate 4b is welded to the end portion 4c on the Z2 side of the columnar portion 4a.

[0058] The positive current collector plate 4b is arranged on the side opposite to the positive terminal 3 (Z2 side) with respect to the internal gasket 6 so as to extend crossing (orthogonally) the Z direction. Specifically, the positive current collector plate 4b is arranged in close contact with the surface on the Z2 side of the internal gasket 6.

[0059] The external gasket 5 is arranged outside the housing 2. Specifically, the external gasket 5 is sandwiched between the positive terminal 3 and the upper cover 2a of the housing 2. Thereby, the positive terminal 3 and the housing 2 (upper cover 2a) are insulated.

[0060] A through hole 5a is formed in the external gasket 5 (refer to Figure 7 ). The columnar portion 4a extends from the positive terminal 3 through the through hole 5a to the positive current collector plate 4b. In addition, the through hole 5a is an example of the "third through hole" of the present disclosure.

[0061] The internal gasket 6 is arranged inside the housing 2. Specifically, the internal gasket 6 is arranged between the upper cover 2a of the housing 2 and the positive current collector plate 4b. Thereby, the upper cover 2a of the housing 2 and the positive current collector plate 4b are insulated.

[0062] A through hole 6a is formed in the internal gasket 6. The through hole 6a is arranged at the center of the internal gasket 6 when viewed along the Z direction. The columnar portion 4a extends from the positive terminal 3 through the through hole 6a to the positive current collector plate 4b.

[0063] In addition, the internal gasket 6 includes a protruding portion 6b. The protruding portion 6b protrudes from the outer peripheral edge of the internal gasket 6 toward the Z2 side. The protruding portion 6b is arranged so as to partition the positive current collector plate 4b and the peripheral wall portion 2c. Thereby, the positive current collector plate 4b and the peripheral wall portion 2c are insulated. In addition, the through hole 6a is an example of the "first through hole" of the present disclosure.

[0064] The negative current collector plate 7 is housed in the housing 2. The negative current collector plate 7 is welded to a negative uncoated portion 21b of the negative electrode plate 20 described later. In addition, the negative current collector plate 7 is in contact with the lower cover 2b of the housing 2.

[0065] A through hole 7a is formed in the negative current collector plate 7. The through hole 7a is arranged at a position overlapping the exhaust valve 8 in the Z direction. Thereby, the exhaust can be easily guided to the exhaust valve 8 through the through hole 7a.

[0066] Figure 5 is a plan view of the positive current collector plate 4b. The positive current collector plate 4b has a disc shape. The positive current collector plate 4b includes a central portion 4c, spokes 4d, an outer peripheral edge portion 4e, and a tab portion 4f.

[0067] The central portion 4c is provided at the center of the positive current collector plate 4b. The columnar portion 4a is 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 with the central portion 4c of the positive current collector plate 4b as the center.

[0068] The outer peripheral edge portion 4e is provided at the outer peripheral edge of the positive current collector plate 4b. The six spokes 4d connect the outer peripheral edge portion 4e and the central portion 4c respectively. The spokes 4d are formed so as to flex in the Z direction. In addition, the central portion 4c in the positive current collector plate 4b moves (displaces) most significantly in the Z direction.

[0069] Through holes 4g are formed between the spokes 4d adjacent to each other in the circumferential direction. That is, six through holes 4g are formed. Plate portions 4f are provided inside each of the six through holes 4g. The six plate portions 4f are connected to the outer peripheral edge portion 4e through connecting portions 4h respectively. The six plate portions 4f are joined to the positive current collector plate 4b by welding respectively. In addition, the six plate portions 4f each have a shape with a tapered tip as going radially inward.

[0070] Figure 6 It is a plan view of the negative current collector plate 7. The negative current collector plate 7 has a circular plate shape. The negative current collector plate 7 includes a central portion 7b, spokes 7c, an outer peripheral edge portion 7d, and plate portions 7e.

[0071] The central portion 7b is provided at the center of the negative current collector plate 7. The spokes 7c are provided so as to extend radially outward from the central portion 7b. Through holes 7a are provided in the central portion 7b. Six spokes 7c are provided at equal angular intervals with the central portion 7b of the negative current collector plate 7 as the center.

[0072] The outer peripheral edge portion 7d is provided at the outer peripheral edge of the negative current collector plate 7. The six spokes 7c connect the outer peripheral edge portion 7d and the central portion 7b respectively. Each spoke 7c is formed so as to flex in the Z direction. The outer peripheral edge portion 7d in the negative current collector plate 7 moves (displaces) most significantly in the Z direction.

[0073] Through holes 7f are formed between the spokes 7c adjacent to each other in the circumferential direction. That is, six through holes 7f are formed. Plate portions 7e are provided inside each of the six through holes 7f. The six plate portions 7e are connected to the outer peripheral edge portion 7d through connecting portions 7g respectively. The six plate portions 7e are joined to the negative current collector plate 7 by welding respectively. In addition, the six plate portions 7e each have a shape with a tapered tip as going radially inward.

[0074] As Figure 7As shown, the positive electrode plate 10 includes a positive electrode current collector 11 and a positive electrode composite material 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 the portion of the positive electrode current collector 11 coated with the positive electrode composite material layer 12. The positive electrode uncoated portion 11b is the portion of the positive electrode current collector 11 not coated with the positive electrode composite material layer 12 (exposed portion). The positive electrode composite material layer 12 is coated on both sides in the radial direction (R direction) of the positive electrode coated portion 11a.

[0075] The positive electrode uncoated portion 11b is located on the Z1 side of the positive electrode coated portion 11a. Specifically, the positive electrode uncoated portion 11b protrudes from the positive electrode coated portion 11a toward the Z1 side. The positive electrode composite material layer 12 is in close contact with the separator 30.

[0076] The positive electrode current collector 11 is formed of, for example, aluminum or the like. The positive electrode composite material layer 12 is formed by coating the surface of the positive electrode current collector 11 with a positive electrode paste and drying it. The positive electrode paste is a paste prepared by kneading the materials of the positive electrode composite material layer 12 (positive electrode active material, binder, etc.) and a solvent. The positive electrode composite material layer 12 is in close contact with the separator 30. The thickness t12 of the positive electrode composite material layer 12 is, for example, 0.1 μm or more and 1000 μm or less.

[0077] The positive electrode uncoated portion 11b is bent inward in the radial direction by abutting against the positive electrode current collector plate 4b disposed on the Z1 side. The positive electrode current collector plate 4b is positively charged by contacting the positive electrode uncoated portion 11b. In addition, the positive electrode uncoated portion 11b and the positive electrode current collector plate 4b are joined by welding. Thus, the positive electrode current collector plate 4b is positively charged. Further, the positive electrode terminal 3 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 by the positive electrode connection portion 4.

[0078] As Figure 8 As shown, the negative electrode plate 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 the portion of the negative electrode current collector 21 coated with the negative electrode composite material layer 22. The negative electrode uncoated portion 21b is the portion of the negative electrode current collector 21 not coated with the negative electrode composite material layer 22 (exposed portion). The negative electrode composite material layer 22 is coated on both sides in the radial direction (R direction) of the negative electrode coated portion 21a.

[0079] The negative electrode uncoated portion 21b is located on the Z2 side of the negative electrode coated portion 21a. Specifically, the negative electrode uncoated portion 21b protrudes from the negative electrode coated portion 21a toward the Z2 side. The negative electrode composite material layer 22 is in close contact with the separator 30.

[0080] The negative electrode current collector 21 is formed of, for example, copper or the like. The negative electrode composite material layer 22 is formed by coating the surface of the negative electrode current collector 21 with a negative electrode paste and drying it. The negative electrode paste is a paste prepared by kneading the materials of the negative electrode composite material layer 22 (negative electrode active material, binder, etc.) and a solvent. The thickness t22 of the negative electrode composite material layer 22 is, for example, 0.1 μm or more and 1000 μm or less.

[0081] The uncoated portion 21b of the negative electrode is bent radially inward by contacting the negative electrode current collector plate 7 disposed on the Z2 side. The negative electrode current collector plate 7 is negatively charged by contacting the uncoated portion 21b of the negative electrode. Thus, the lower lid 2b 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 outer casing 2. In addition, since the lower lid 2b, the peripheral wall portion 2c, and the upper lid 2a are electrically connected, the peripheral wall portion 2c and the upper lid 2a are each negatively charged.

[0082] Here, in a conventional power storage unit, sometimes exhaust gas is discharged (leaked) from the side opposite to the side where the exhaust valve is provided, and the exhaust gas cannot be efficiently discharged from the exhaust valve.

[0083] Therefore, in the present embodiment, as Figure 7 shown, the internal gasket 6 is disposed so as to cover the through hole 2g from the inside of the outer casing 2. Specifically, the internal gasket 6 is disposed so as to fill the gap S (see Figure 2 ) formed between the through hole 2g and the columnar portion 4a when viewed from the Z1 side.

[0084] The columnar portion 4a may also be press-fitted into the through hole 6a of the internal gasket 6. That is, the outer peripheral surface of the columnar portion 4a and the inner peripheral surface of the through hole 6a may be in close contact. Thus, the through hole 6a is blocked by the columnar portion 4a, and therefore it is possible to suppress the exhaust gas from being discharged to the outside of the outer casing 2 through the through hole 6a.

[0085] In addition, although not shown in the figure, the internal gasket 6 has a disc shape when viewed along the Z direction. The internal gasket 6 has a diameter with a length L2 (see Figure 1 ). In addition, the through hole 6a of the internal gasket 6 has a circular shape when viewed along the Z direction (see Figure 2 ). The through hole 6a has a diameter with a length L3. In addition, the through hole 5a of the external gasket 5 has the same shape as the through hole 6a. That is, the through hole 5a has a diameter with a length L3.

[0086] The internal gasket 6 is sandwiched between the upper cover 2a and the positive current collector plate 4b in the Z direction. That is, the internal gasket 6 is arranged such that, in addition to the surface on the Z2 side of the internal gasket 6 being in close contact with the positive current collector plate 4b as described above, the surface on the Z1 side of the internal gasket 6 is in close contact with the upper cover 2a. That is, no gaps are formed between the internal gasket 6 and the positive current collector plate 4b and between the internal gasket 6 and the upper cover 2a, respectively.

[0087] The internal gasket 6 can also be formed of an elastic resin or the like. The internal gasket 6 can also be elastically deformed by being pressed by the upper cover 2a and the positive current collector plate 4b in the Z direction.

[0088] The internal gasket 6 has a thickness t1 in the Z direction. In addition, 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 larger than the maximum value of the thickness t2 of the external gasket 5. Moreover, the minimum value of the thickness t1 of the internal gasket 6 is larger than the maximum value of the thickness t3 of the upper cover 2a in the Z direction.

[0089] The external gasket 5 is arranged so as to cover the through hole 2g of the upper cover 2a from the outside of the housing 2. Specifically, the external gasket 5 is arranged so as to fill the gap S (refer to Figure 9 ) formed between the through hole 2g and the columnar portion 4a when viewed from the Z2 side.

[0090] The columnar portion 4a can also be press-fitted into the through hole 5a of the external gasket 5. That is, the outer peripheral surface of the columnar portion 4a and the inner peripheral surface of the through hole 5a can be in close contact. Thus, the through hole 5a is blocked by the columnar portion 4a, so that it is possible to suppress the exhaust gas from being discharged to the outside of the housing 2 through the through hole 5a.

[0091] The external gasket 5 has a disc shape. The diameter of the external gasket 5 has a length L4. The length L4 is larger than the length L1 of the diameter of the through hole 2g of the upper cover 2a.

[0092] As described above, in the present embodiment, the internal gasket 6 is arranged so as to cover the through hole 2g of the upper cover 2a from the inside of the housing 2. Thus, inside the housing 2, the through hole 2g is blocked by the internal gasket 6, so that it is possible to suppress the exhaust gas from leaking from the through hole 2g to the outside of the housing 2. As a result, the exhaust gas can be efficiently discharged from the exhaust valve 8.

[0093] In addition, compared with the case of forming the housing by deep drawing a metal plate or the like, by using the upper cover 2a and the lower cover 2b to form the housing 2, the manufacturing process and manufacturing apparatus of the housing 2 can be simplified.

[0094] In the above embodiment, an example in which the internal gasket 6 is sandwiched between the upper cover 2a and the positive current collector plate 4b in the Z direction is shown, but the present disclosure is not limited thereto. For example, a slight gap may be formed between the internal gasket 6 and the upper cover 2a.

[0095] In the above-described embodiment, an example in which the thickness t1 of the internal gasket 6 in the Z direction is larger than the thickness t2 of the external gasket 5 in the Z direction is shown, but the present disclosure is not limited thereto. The thickness t1 may also be less than or equal to the thickness t2.

[0096] In the above-described embodiment, an example in which the internal gasket (sealing member) is disposed in close contact with the positive current collector plate (plate portion) is shown, but the present disclosure is not limited thereto. The internal gasket (sealing member) may also be disposed in close contact with the negative current collector plate (plate portion).

[0097] In the above-described embodiment, an example in which the upper lid 2a and the peripheral wall portion 2c and the lower lid 2b and the peripheral wall portion 2c are joined by welding, respectively, is shown, but the present disclosure is not limited thereto. At least one of the above may also be connected by caulking (chiseling).

[0098] It should be considered that the embodiments disclosed herein are illustrative and not restrictive in all respects. The scope of the present disclosure is represented not by the description of the above embodiments but by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

Claims

1. A power storage unit, characterized in that: have: A wound electrode body comprising a first electrode and a second electrode; A housing for housing the wound electrode body; a sealing member, which is received in the housing and has a first through hole; external terminals; and a connecting member electrically connecting the external terminal and the first electrode, The housing comprises: A peripheral wall portion is arranged on the outer peripheral side of the wound electrode body and extends in a cylindrical shape along the axial direction of the wound electrode body; a first cover portion that closes one axial end of the peripheral wall portion; and The second cover portion closes the other axial end of the peripheral wall portion. The first cover has an exhaust valve for exhausting gas in the housing. The second cover portion is formed with a second through hole that connects the inside and the outside of the housing. The connecting member includes a columnar portion extending in the axial direction so as to penetrate the second through hole of the second cover portion and the first through hole of the sealing member. The sealing member is arranged so as to cover the second through hole from the inner side of the housing.

2. The power storage unit according to claim 1, characterized in that: The connecting member further includes a plate-shaped portion connected to the columnar portion on the inner side of the housing, The plate-shaped portion is arranged on the side of the sealing member opposite to the external terminal so as to extend intersecting with the axial direction.

3. The power storage unit according to claim 2, characterized in that: The sealing member is sandwiched between the second cover portion and the plate-shaped portion in the axial direction.

4. The power storage unit according to any one of claims 1 to 3, characterized in that: further comprising an insulating member arranged so as to cover the second through hole of the second cover portion from the outside of the housing, The second cover is electrically connected to the second electrode. The insulating member is formed with a third through hole through which the columnar portion passes, and is arranged to insulate the second cover portion from the external terminal.

5. The power storage unit according to claim 4, characterized in that: A thickness of the sealing member in the axial direction is greater than a thickness of the insulating member in the axial direction.

Images