Electrode assemblies, batteries, battery packs containing them, and automobiles

Abstract

The present invention discloses an electrode assembly, a battery, a battery pack including the same, and a vehicle. The first electrode of the electrode assembly includes a first active material portion coated with an active material layer along a winding direction, and a first uncoated portion that is not coated with the active material layer and is exposed outside the separator. The first uncoated portion includes a first portion adjacent to the core of the electrode assembly, a second portion adjacent to the outer peripheral surface of the electrode assembly, and a third portion between the first portion and the second portion. The third portion includes a plurality of segmented pieces spaced apart along the winding direction by a plurality of cutting grooves extending in the winding axis direction. The height of the first portion is relatively lower than the height of the uncoated portion at the lower end of the cutting groove.

Claims

1. An electrode assembly having a core and an outer surface defined by winding a first electrode, a second electrode, and a separation membrane interposed between the first electrode and the second electrode around a winding shaft, The first electrode includes a first active material portion coated with an active material layer along the winding direction, and a first plain portion that is not coated with an active material layer and is exposed to the outside of the separation membrane. The first blank portion includes a first portion adjacent to the core of the electrode assembly, a second portion adjacent to the outer circumferential surface of the electrode assembly, and a third portion between the first portion and the second portion. The third portion includes a plurality of segmental sections separated in the winding direction by a plurality of cutting grooves extending in the winding axis direction, An electrode assembly in which, when the height toward the outer end of the first blank portion is measured in the winding axis direction with respect to the end of the active material layer, the height of the first portion is relatively lower than the height of the blank portion at the lower end of the cutting groove.

2. The electrode assembly according to claim 1, wherein, with respect to the end of the active material layer, the height of the first portion is more than 0% and less than or equal to 95% of the height of the plain portion at the lower end of the cutting groove.

3. The electrode assembly according to claim 2, wherein the height of the first portion is 37.5% to 62.5% of the height of the plain portion at the lower end of the cutting groove.

4. The present invention further includes an insulating coating layer covering the boundary between the first plain portion and the active material layer, The electrode assembly according to any one of claims 1 to 3, wherein, with respect to the edge of the insulating coating layer, the height of the first portion is more than 0% and less than or equal to 95% of the height of the plain portion at the lower end of the cutting groove.

5. The electrode assembly according to claim 4, wherein the height of the first portion is 37.5% to 62.5% of the height of the plain portion at the lower end of the cutting groove.

6. The electrode assembly according to any one of claims 1 to 3, wherein when the height toward the outer end of the first blank portion is measured in the winding axis direction with respect to the end of the active material layer, the height of the second portion is relatively lower than the height of the blank portion at the lower end of the cutting groove.

7. The electrode assembly according to claim 6, wherein, with respect to the end of the active material layer, the height of the second portion is more than 0% and less than or equal to 95% of the height of the plain portion at the lower end of the cutting groove.

8. The electrode assembly according to claim 7, wherein the height of the second portion is 37.5% to 62.5% of the height of the plain portion at the lower end of the cutting groove.

9. The present invention further includes an insulating coating layer covering the boundary between the first plain portion and the active material layer, The electrode assembly according to claim 6, wherein, with respect to the edge of the insulating coating layer, the height of the second portion is more than 0% and less than or equal to 95% of the height of the plain portion at the lower end of the cutting groove.

10. The electrode assembly according to claim 9, wherein the height of the second portion is 37.5% to 62.5% of the height of the plain portion at the lower end of the cutting groove.

11. The electrode assembly according to any one of claims 1 to 3, wherein the current collector of the first electrode is thinner than the current collector of the second electrode.

12. The electrode assembly according to claim 11, wherein the current collector of the first electrode is copper foil, and the current collector of the second electrode is aluminum foil.

13. The electrode assembly according to any one of claims 1 to 3, wherein the first electrode is a negative electrode.

14. An electrode assembly according to any one of claims 1 to 3, A battery housing having an open end and a bottom facing the open end, housing the electrode assembly in the space between the open end and the bottom, and electrically connected to one of the first electrode and the second electrode to have a first polarity, A sealing body that seals the open end of the battery housing, A battery comprising a terminal having a second polarity, electrically connected to the other of the first electrode and the second electrode, with its surface exposed to the outside.

15. The sealing body includes a cap plate that seals the open end of the battery housing, and a gasket that wraps around the periphery of the cap plate and is crimped to the open end of the battery housing. The battery according to claim 14, wherein the terminal having the second polarity is the cap plate.

16. The present invention further includes a current collector that is electrically connected to the plain portion of the first electrode having the first polarity, and whose peripheral edge is coupled to the side wall of the battery housing, The sealing body includes a cap plate and a gasket that wraps around the periphery of the cap plate and is crimped to the open end of the battery housing. The battery according to claim 14, wherein the battery housing is insulatedly mounted in a through hole formed in the center of the bottom and includes a rivet terminal electrically connected to the second electrode and having the second polarity.

17. The battery according to claim 16, wherein the cap plate has no polarity.

18. A battery pack comprising a plurality of batteries as described in claim 14.

19. An automobile comprising the battery pack described in claim 18.

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