SECONDARY BATTERY, BATTERY MODULE, BATTERY PACK, AND ELECTRIC APPARATUS

1 . A secondary battery, comprising:

a negative electrode plate;

wherein:

a negative electrode active material layer of the negative electrode plate comprises a porous carbon material;

the negative electrode active material layer has a pore, the pore running through or not through the negative electrode active material layer; and

lithium metal is present in the pore.

2 . The secondary battery according to claim 1 , further comprising:

a positive electrode plate;

wherein a ratio CB of a reversible lithiation capacity of the negative electrode plate to a reversible delithiation capacity of the positive electrode plate satisfies: 0<CB≤1.

3 . The secondary battery according to claim 1 , wherein a thickness x of the negative electrode active material layer and a distance y between two end openings of the pore in a direction perpendicular to the negative electrode active material layer satisfy: 0.1x≤y≤x.

4 . The secondary battery according to claim 1 , wherein a length L between two end openings of the pore along an inner wall of the pore and a distance y between the two end openings of the pore in a direction perpendicular to the negative electrode active material layer satisfy: L>y.

5 . The secondary battery according to claim 1 , wherein the pore is a non-linear pore.

6 . The secondary battery according to claim 1 , wherein a projection of interior of the pore on a current collector in a direction perpendicular to the negative electrode active material layer does not overlap with two end openings of the pore.

7 . The secondary battery according to claim 1 , wherein the pore is one of a plurality of pores in the negative electrode active material layer, and a thickness x of the negative electrode active material layer and a distance d between adjacent two of the pores satisfy d≤10x.

8 . The secondary battery according to claim 1 , wherein a maximum diameter of the pore is 1 μm-50 μm.

9 . The secondary battery according to claim 1 , wherein the porous carbon material comprises at least one selected from hard carbon, biomass carbon, activated carbon, carbon fibers, and carbon aerogel.

10 . The secondary battery according to claim 1 , wherein D v 50 of the porous carbon material is 1 μm-100 μm.

11 . The secondary battery according to claim 1 , wherein a specific surface area of the porous carbon material in a carbon dioxide atmosphere is greater than or equal to 50 m 2 /g.

12 . The secondary battery according to claim 1 , wherein an oil absorption value of the porous carbon material determined using Gardner-Coleman method is greater than or equal to 30 mL/100 g.

13 . The secondary battery according to claim 1 , wherein a ratio of a specific surface area of the negative electrode plate in a carbon dioxide atmosphere to a specific surface area of the negative electrode plate in a nitrogen atmosphere is greater than or equal to 5.

14 . The secondary battery according to claim 1 , wherein in the negative electrode active material layer, a mass percentage of the porous carbon material is 90%-98%.

15 . The secondary battery according to claim 1 , wherein a current collector of the negative electrode plate comprises a copper foil, the copper foil containing at least one element for lithiation.

16 . The secondary battery according to claim 15 , wherein a mass percentage of the element for lithiation in the copper foil is greater than or equal to 5%.

17 . The secondary battery according to claim 15 , wherein the element for lithiation comprises at least one of silver, zinc, magnesium, aluminum, tin, or silicon.

18 . The secondary battery according to claim 15 , wherein a thickness of the copper foil is 4 μm-20 μm.

19 . The secondary battery according to claim 1 , the negative electrode plate is prepared by:

pretreating the porous carbon material so that the porous carbon material adsorbs gas;

preparing a negative electrode slurry from the porous carbon material with the gas adsorbed; and

preparing the negative electrode active material layer by using the negative electrode slurry on at least one surface of a current collector, the gas being desorbed from the porous carbon material to form the pore.

20 . A battery module, comprising the secondary battery according to claim 1 .