METHOD FOR PREPARING PRELITHIATED POSITIVE ELECTRODE CURRENT COLLECTOR, POSITIVE ELECTRODE CURRENT COLLECTOR, AND LITHIUM-ION BATTERY

1 . A method for preparing a prelithiated positive electrode current collector, comprising the following steps:

gasifying a lithium source in an evaporation chamber filled with a protective gas;

enabling an aluminum foil layer to pass through the evaporation chamber and depositing the metal lithium on a surface of the aluminum foil layer by means of vapor deposition; and

transferring the aluminum foil layer deposited with the metal lithium to an annealing chamber filled with a protective gas and performing high-temperature annealing to form a lithium-aluminum alloy layer on the surface of the aluminum foil layer.

2 . The preparation method according to claim 1 , comprising:

evacuating the evaporation chamber to a vacuum degree of 10 −6 to 10 2 Pa, heating the lithium source to 300-800° C., and gasifying the lithium source;

evacuating the evaporation chamber to a vacuum degree of 10 −2 to 10 Pa; and

heating the lithium source to 500-750° C.

3 . The preparation method according to claim 1 , comprising:

enabling the aluminum foil layer to pass through the evaporation chamber at a speed of 0.1-100 m/min; and

enabling the aluminum foil layer to pass through the evaporation chamber at a speed of 1-30 m/min.

4 . The preparation method according to claim 1 , wherein during the high-temperature annealing, heating same to the highest temperature of 200-600° C. at a heating rate of 0.1-10° C./min, maintaining the temperature for a time of 0.1-24 hours, and then cooling same to room temperature at a cooling rate of 0.1-5° C./min.

5 . The preparation method according to claim 4 , wherein during the high-temperature annealing, the heating rate is 0.5-3° C./min; the highest temperature is 400-500° C.; the temperature maintaining time is 2-4 hours; and the cooling rate is 0.5-2° C./min

6 . The preparation method according to claim 1 , wherein the lithium source is metal lithium powder, metal lithium strips, or metal lithium wires; and the protective gas is argon or helium.

7 . The preparation method according to claim 1 , wherein the thickness of the aluminum foil layer is 5-50 μm; and the thickness of the lithium-aluminum alloy layer is 0.1-10 μm.

8 . A positive electrode current collector comprising an aluminum foil layer and a lithium-aluminum alloy layer formed on the aluminum foil layer, and the positive electrode current collector being obtained by:

gasifying a lithium source in an evaporation chamber filled with a protective gas;

enabling an aluminum foil layer to pass through the evaporation chamber and depositing the metal lithium on a surface of the aluminum foil layer by means of vapor deposition; and

transferring the aluminum foil layer deposited with the metal lithium to an annealing chamber filled with a protective gas and performing high-temperature annealing to form a lithium-aluminum alloy layer on the surface of the aluminum foil layer.

9 . A lithium-ion battery, having a positive electrode plate, a separator, a negative electrode plate, and an electrolyte solution, wherein the positive electrode comprises a positive electrode current collector comprising an aluminum foil layer and a lithium-aluminum alloy layer formed on the aluminum foil layer, and the positive electrode current collector being obtained by:

gasifying a lithium source in an evaporation chamber filled with a protective gas;

enabling an aluminum foil layer to pass through the evaporation chamber and depositing the metal lithium on a surface of the aluminum foil layer by means of vapor deposition; and

transferring the aluminum foil layer deposited with the metal lithium to an annealing chamber filled with a protective gas and performing high-temperature annealing to form a lithium-aluminum alloy layer on the surface of the aluminum foil layer.