CN-122029687-A - Power storage device

Abstract

The battery (10) is provided with an electrode body (14) formed by winding a strip-shaped positive electrode (11) and a strip-shaped negative electrode (12) through a strip-shaped separator (13), an outer can (16) which accommodates the electrode body (14) and comprises a cylindrical portion (30), and a sealing body (17) which seals the opening of the outer can (16). The negative electrode (12) has a first end and a second end in the axial direction of the electrode body (14). The negative electrode (12) is electrically connected from the first end side. A second exposed portion (buffer portion) (46) protruding outward in the axial direction from the region on the outer peripheral side of the electrode body (14) is formed at the second end. The second exposed portion (46) constitutes a buffer portion.

Inventors

• SAKAMOTO, SHINICHI
• GESHI SHINYA
• KOZUKI KIYOMI

Assignees

• 松下知识产权经营株式会社

Dates

Publication Date

20260512

Application Date

20241031

Priority Date

20231031

Claims (11)

1. 1. A power storage device is provided with: An electrode body formed by winding a band-shaped first electrode and a band-shaped second electrode through a band-shaped separator; An exterior can containing the electrode body and including a cylindrical portion, and A sealing body for sealing the opening of the outer can, Wherein the first electrode has a first end and a second end in an axial direction of the electrode body, The first electrode collects electricity from the first end side, A buffer portion protruding outward in the axial direction than an inner peripheral side region of the electrode body is formed at the second end.
2. 2. The power storage device according to claim 1, wherein, The outer peripheral surface of the cylindrical portion of the outer can has a groove portion recessed so that an inner peripheral portion of the cylindrical portion protrudes inward, The buffer portion overlaps the groove portion in the axial direction.
3. 3. The power storage device according to claim 1, wherein, The first electrode has a strip-shaped core and a first mixture layer formed on the core.
4. 4. The power storage device according to claim 3, wherein, The first end of the core body is provided with a first exposed part which is exposed by the core body without forming the first mixture layer.
5. 5. The power storage device according to claim 3, wherein, A second exposed portion where the first mixture layer is not formed and the core is exposed is provided at a second end of the core, The buffer portion is formed in the second exposed portion.
6. 6. The power storage device according to claim 1, wherein, The buffer portion is curved in a radial direction.
7. 7. The power storage device according to claim 5, wherein, A resin layer is formed on the second exposed portion.
8. 8. The power storage device according to claim 1 or 2, wherein, Including a dispersion portion in which a part of the second ends adjacent in the radial direction are directly engaged with or in contact with each other, or including a dispersion portion in which a part of the second ends adjacent in the radial direction are indirectly engaged with or in contact with each other via a connecting member having conductivity.
9. 9. The power storage device according to claim 1 or 2, wherein, And a collector plate electrically connected to the second end.
10. 10. The power storage device according to claim 1 or 2, wherein, The length of the second end in the axial direction becomes smaller stepwise or continuously as going from the outer peripheral side to the inner peripheral side of the first electrode.
11. 11. The power storage device according to claim 1, wherein, In the axial direction, the second electrode collects electricity from a side against the second end of the first electrode, The second electrode is electrically connected to the buffer portion on the inner peripheral side.

Description

Power storage device Technical Field The present disclosure relates to an electric storage device, for example, to a battery and a capacitor. Background Conventionally, there is a cylindrical battery described in patent document 1 as a power storage device. The cylindrical battery includes an electrode body in which a positive electrode and a negative electrode are wound with a separator interposed therebetween, a bottomed tubular outer can accommodating the electrode body, and a sealing body closing an opening of the outer can. The outer can has a cylindrical portion and a bottom portion, the cylindrical portion including an annular groove portion and an annular shoulder portion. The groove portion is formed by recessing a part of the cylindrical portion radially inward. The shoulder portion extends radially inward at an upper end of the cylindrical portion. The sealing body is held between the groove and the shoulder via the gasket, and is thereby fixed to the outer can. The end of the electrode body on the sealing body side in the axial direction is constituted by a positive electrode core exposed portion, and the end of the electrode body on the bottom plate portion side of the outer can in the axial direction is constituted by a negative electrode core exposed portion. The positive electrode core exposed portion is bound from the outer periphery side to the inner periphery side and welded to an upper current collecting plate, and the upper current collecting plate is electrically connected to the sealing body. The negative electrode substrate exposed portion is bound from the outer periphery side to the inner periphery side and welded to a lower current collecting plate, and the lower current collecting plate is welded to a bottom plate portion of the outer can. The positive electrode terminal is constituted by a terminal cap of the sealing body electrically connected to the positive electrode substrate exposed portion via the upper current collecting plate, and the negative electrode terminal is constituted by an outer can electrically connected to the negative electrode substrate exposed portion via the lower current collecting plate. Prior art literature Patent literature Patent document 1 Japanese patent application laid-open No. 2018-056091 Disclosure of Invention In recent years, in the field of power storage devices including the cylindrical batteries, a highly reliable power storage device is desired in order to increase the capacity and output or use the device in an environment with more severe conditions. In order to solve the above-described problems, a power storage device according to the present disclosure includes an electrode body formed by winding a first electrode in a band shape and a second electrode in a band shape with a band-shaped separator interposed therebetween, an outer can accommodating the electrode body and including a cylindrical portion, and a sealing body closing an opening of the outer can, wherein the first electrode has a first end and a second end in an axial direction of the electrode body, the first electrode is electrically connected to the first end, and a buffer portion protruding outward in the axial direction than an inner peripheral region of the electrode body is formed at the second end. According to the power storage device of the present disclosure, reliability can be improved. Drawings Fig. 1 is a cross-sectional view in the axial direction of a cylindrical battery according to a first embodiment of an electric storage device of the present disclosure. Fig. 2 is a schematic plan view of the negative electrode when the negative electrode is developed in a long form. Fig. 3 is a diagram illustrating an example of a method of bonding the groove portion, the second upper current collector plate, and the upper negative electrode substrate exposed portion. Fig. 4 (a) is a diagram illustrating a structure of a second upper collector plate, fig. 4 (b) is a diagram illustrating a structure of a second upper collector plate according to a first modification, and fig. 4 (c) is a diagram illustrating a structure of a second upper collector plate according to a second modification. Fig. 5 is a sectional view corresponding to fig. 1 of a cylindrical battery according to a first modification. Fig. 6 is a schematic plan view of the negative electrode according to the second modification corresponding to fig. 2. Fig. 7 is a schematic plan view of the negative electrode according to the third modification example, corresponding to fig. 2. Fig. 8 is a schematic plan view of the negative electrode according to the fourth modification corresponding to fig. 2. Fig. 9 is a schematic plan view of the negative electrode of the fifth modification corresponding to fig. 2. Fig. 10 is a sectional view corresponding to fig. 1 of a cylindrical battery of the second embodiment. Fig. 11 is a schematic plan view of the cylindrical battery according to the second embodiment when the po