Electrode assembly, battery cell, battery, and electrical device

1. An electrode assembly, comprising first electrode plates and a second electrode plate that are of opposite polarities, wherein the second electrode plate and two first electrode plates are stacked and wound to form the electrode assembly, and the second electrode plate is located between the two first electrode plates, wherein

each of the first electrode plates comprises a first composite current collector and a first active material layer, the first active material layer is disposed on a surface that is of the first composite current collector and that is oriented back from the second electrode plate, and the first composite current collector is configured to dielectrically isolate the first active material layer from the second electrode plate and allow passage of ions transmitted between the first active material layer and the second electrode plate.

2. The electrode assembly according to claim 1 , wherein the first composite current collector comprises a first insulative layer and a first conductive layer that are stacked;

the first insulative layer is located between the first conductive layer and the second electrode plate, and the first insulative layer is configured to dielectrically isolate the first conductive layer from the second electrode plate; and

the first active material layer is disposed on a surface that is of the first conductive layer and that is oriented back from the first insulative layer.

3. The electrode assembly according to claim 2 , wherein an air permeability of the first insulative layer is 50 to 3000 s/100 cc.

4. The electrode assembly according to claim 2 , wherein a porosity of the first conductive layer is 10% to 95%.

5. The electrode assembly according to claim 2 , wherein a thickness of the first conductive layer is 200 to 3000 nm.

6. The electrode assembly according to claim 2 , wherein the first conductive layer comprises a first transition layer, a first thickening layer, and a first functional layer that are stacked in sequence, the first transition layer is located between the first insulative layer and the first thickening layer, and the first active material layer is disposed on a surface that is of the first functional layer and that is oriented back from the first thickening layer.

7. The electrode assembly according to claim 1 , wherein the second electrode plate comprises a current collector and a second active material layer, and the second active material layer is disposed on two opposite surfaces of the current collector, wherein

the first composite current collector is located between the first active material layer and the second active material layer, the first composite current collector is configured to dielectrically isolate the first active material layer from the second active material layer and allow passage of ions transmitted between the first active material layer and the second active material layer.

8. The electrode assembly according to claim 7 , wherein the current collector in the second electrode plate is a second composite current collector that allows passage of ions.

9. The electrode assembly according to claim 8 , wherein the second composite current collector comprises a second insulative layer and a second conductive layer that are stacked; and

the second conductive layer is disposed on two opposite surfaces of the second insulative layer, and the second active material layer is disposed on a surface that is of the second conductive layer and that is oriented back from the second insulative layer.

10. The electrode assembly according to claim 9 , wherein an air permeability of the second insulative layer is 50 to 3000 s/100 cc.

11. The electrode assembly according to claim 9 , wherein a porosity of the second conductive layer is 10% to 95%.

12. The electrode assembly according to claim 9 , wherein a thickness of the second conductive layer is 200 to 3000 nm.

13. The electrode assembly according to claim 9 , wherein the second conductive layer comprises a second transition layer, a second thickening layer, and a second functional layer that are stacked in sequence, the second transition layer is located between the second insulative layer and the second thickening layer, and the second active material layer is disposed on a surface that is of the second functional layer and that is oriented back from the second thickening layer.

14. The electrode assembly according to claim 7 , wherein the first electrode plates are positive electrode plates, and the second electrode plate is a negative electrode plate; and

a width of the second active material layer is greater than a width of the first active material layer.

15. A battery cell, comprising:

the electrode assembly according to claim 1 ; and

a housing, configured to accommodate the electrode assembly.

16. A battery, comprising:

the battery cell according to claim 15 ; and

a box, configured to accommodate the battery cell.

17. An electrical device, comprising the battery according to claim 16 .

18. A method for manufacturing an electrode assembly, wherein the manufacturing method comprises:

providing first electrode plates and a second electrode plate;

stacking the second electrode plate and two first electrode plates and then winding the electrode plates to form the electrode assembly, wherein

the first electrode plates are of a polarity opposite to the second electrode plate, the second electrode plate is located between the two first electrode plates, each of the first electrode plates comprises a first composite current collector and a first active material layer, the first active material layer is disposed on a surface that is of the first composite current collector and that is oriented back from the second electrode plate, and the first composite current collector is configured to dielectrically isolate the first active material layer from the second electrode plate and allow passage of ions transmitted between the first active material layer and the second electrode plate.

19. A device for manufacturing an electrode assembly, wherein the manufacturing device comprises:

a providing apparatus, configured to provide first electrode plates and a second electrode plate; and

an assembling apparatus, configured to stack the second electrode plate and two first electrode plates and then wind the electrode plates to form the electrode assembly, wherein

the first electrode plates are of a polarity opposite to the second electrode plate, the second electrode plate is located between the two first electrode plates, each of the first electrode plates comprises a first composite current collector and a first active material layer, the first active material layer is disposed on a surface that is of the first composite current collector and that is oriented back from the second electrode plate, and the first composite current collector is configured to dielectrically isolate the first active material layer from the second electrode plate and allow passage of ions transmitted between the first active material layer and the second electrode plate.