Electrode member, electrode assembly and secondary battery

1. An electrode member, comprising an electrode body and a conductive structure;

the electrode body being a laminated structure and comprising an insulating substrate and a conducting layer provided on a surface of the insulating substrate;

the conducting layer comprising a first portion and a second portion extending from the first portion, the first portion being coated with an active material, and the second portion being not coated with the active material;

the second portion comprising a main portion and a transition portion, the transition portion being provided between the main portion and the first portion, and a width of the transition portion being larger than a width of the main portion;

the conductive structure being welded with the second portion and extending along a direction away from the first portion, and at least a part of a welding region formed by the second portion and the conductive structure being positioned at the transition portion;

wherein the welding region comprises a first welding region and a second welding region, the first welding region is positioned at the main portion, and the second welding region is positioned at the transition portion; and

a width of the second welding region is larger than a width of the first welding region.

2. The electrode member according to claim 1 , wherein both of two ends of the welding region in a width direction of the second portion extend to edges of the second portion.

3. The electrode member according to claim 1 , wherein a dimension of the first welding region is smaller than 3 mm, and a height of the second welding region is 0.5 mm-2.5 mm.

4. The electrode member according to claim 1 , wherein the second portion is a stepped structure, the main portion is provided to a small end of the stepped structure, and the transition portion is provided to a large end of the stepped structure.

5. The electrode member according to claim 4 , wherein at least at one side of the second portion in a width direction of the second portion, the transition portion and the main portion is connected via a rounded corner.

6. The electrode member according to claim 1 , wherein a gap is kept between the welding region and the first portion.

7. The electrode member according to claim 6 , wherein the electrode member further comprises an insulating layer, the insulating layer is provided in the gap.

8. The electrode member according to claim 1 , wherein

the conductive structure extends beyond the second portion at a side away from the first portion.

9. An electrode assembly, comprising a first electrode member, a second electrode member and a separator which are stacked, the separator being provided between the first electrode member and the second electrode member;

the first electrode member comprising an electrode body and a conductive structure;

the electrode body being a laminated structure and comprising an insulating substrate and a conducting layer provided on a surface of the insulating substrate;

the conducting layer comprising a first portion and a second portion extending from the first portion, the first portion being coated with an active material, and the second portion being not coated with the active material;

the second portion comprising a main portion and a transition portion, the transition portion being provided between the main portion and the first portion, and a width of the transition portion being larger than a width of the main portion;

the conductive structure being welded with the second portion and extending along a direction away from the first portion, and at least a part of a welding region formed by the second portion and the conductive structure being positioned at the transition portion;

wherein the welding region comprises a first welding region and a second welding region, the first welding region is positioned at the main portion, and the second welding region is positioned at the transition portion; and

a width of the second welding region is larger than a width of the first welding region.

10. The electrode assembly according to claim 9 , wherein the electrode assembly is formed by laminating or winding the first electrode member, the second electrode member and separator.

11. The electrode assembly according to claim 9 , wherein

the first electrode member is provided with a plurality of the second portions and a plurality of the conductive structures, each second portion is connected with the conductive structure;

the second portions and the conductive structures of the first electrode member are stacked and form a first electrode tab.

12. The electrode assembly according to claim 9 , wherein the second portion is a stepped structure, the main portion is provided to a small end of the stepped structure, and the transition portion is provided to a large end of the stepped structure.

13. The electrode assembly according to claim 9 , wherein the conductive structure extends beyond the second portion at a side away from the first portion.

14. A secondary battery, comprising a case, a cap plate, a first electrode terminal, a second electrode terminal and an electrode assembly;

the cap plate covering the case;

the first electrode terminal and the second electrode terminal being provided to the cap plate;

the electrode assembly being provided in the case;

the electrode assembly comprising a first electrode member, a second electrode member and a separator which are stacked, the separator being provided between the first electrode member and the second electrode member;

the first electrode member being connected with the first electrode terminal, and the second electrode member being connected with the second electrode terminal;

the first electrode member comprising an electrode body and a conductive structure;

the electrode body being a laminated structure and comprising an insulating substrate and a conducting layer provided on a surface of the insulating substrate;

the conducting layer comprising a first portion and a second portion extending from the first portion, the first portion being coated with an active material, and the second portion being not coated with the active material;

the second portion comprising a main portion and a transition portion, the transition portion being provided between the main portion and the first portion, and a width of the transition portion being larger than a width of the main portion;

the conductive structure being welded with the second portion and extending along a direction away from the first portion, and at least a part of a welding region formed by the second portion and the conductive structure being positioned at the transition portion;

wherein the welding region comprises a first welding region and a second welding region, the first welding region is positioned at the main portion, and the second welding region is positioned at the transition portion; and

a width of the second welding region is larger than a width of the first welding region.

15. The secondary battery according to claim 14 , wherein

the first electrode member is provided with a plurality of the second portions and a plurality of the conductive structures, each second portion is connected with the conductive structure;

the second portions and the conductive structures of the first electrode member are stacked and form a first electrode tab;

the first electrode tab is connected with the first electrode terminal.

16. The secondary battery according to claim 14 , wherein

the secondary battery further comprises a current collecting member, the current collecting member connects the conductive structure and the first electrode terminal.

17. The secondary battery according to claim 16 , wherein

the conductive structure extends beyond the second portion at a side away from the first portion, a part of the conductive structure beyond the second portion is defined as an extending portion;

the extending portion is connected with the current collecting member.