Method for manufacturing lithium electrode
A method for manufacturing a lithium electrode, more particularly, a method for manufacturing a lithium electrode having a thin and uniform thickness by, when manufacturing the lithium electrode, first forming a protective layer capable of protecting lithium metal on the surface treated substrate with a plasma and corona process, and depositing lithium metal on the protective layer and then transferring the deposited lithium metal layer to a current collector. The energy density of the lithium secondary battery manufactured using the lithium electrode thus manufactured can be improved.
1. A method of manufacturing a lithium electrode, comprising the following steps of:
(S1) surface-treating a first surface of a substrate by a plasma process and corona process at atmospheric pressure;
(S2) coating a polymer solution comprising polyvinylidene fluoride-hexafluoropropylene copolymer with N-methyl-2-pyrrolidone as a solvent for protecting lithium metal on the surface-treated substrate to form a protective layer;
(S3) depositing lithium metal on the protective layer to form a lithium metal layer; and
(S4) transferring the lithium metal layer with the protective layer to a current collector,
wherein the plasma and corona process is performed at a power of 0.6 kW or more and less than 1.5 kW.
2. The method of manufacturing the lithium electrode according to claim 1 , wherein the substrate comprises at least one selected from the group consisting of polyethylene terephthalate (PET), polyimide (PI), poly(methylmethacrylate) (PMMA), cellulose tri-acetate (TAC), polypropylene, polyethylene and polycarbonate.
3. The method of manufacturing the lithium electrode according to claim 1 , wherein the substrate has a release layer formed on at least the first surface thereof.
4. The method of manufacturing the lithium electrode according to claim 3 , wherein the release layer comprises at least one selected from the group consisting of Si, melamine and fluorine.
5. The method of manufacturing the lithium electrode according to claim 1 , wherein at least the first surface of the substrate is coated with oligomer block coatings.
6. The method of manufacturing the lithium electrode according to claim 1 , wherein the deposition is performed by a method selected from the group consisting of evaporation deposition, chemical vapor deposition (CVD) and physical vapor deposition.
7. The method of manufacturing the lithium electrode according to claim 1 , wherein the lithium metal layer has a thickness of 5 μm to 50 μm.
8. The method of manufacturing the lithium electrode according to claim 1 , wherein the protective layer further comprises at least one selected from the group consisting of polyvinylidene fluoride (PVDF), cycloolefin polymer, and styrene butadiene rubber-carboxymethyl cellulose (SBR-CMC).
9. The method of manufacturing the lithium electrode according to claim 1 , wherein the current collector comprises one selected from the group consisting of copper, aluminum, nickel, titanium, sintered carbon, and stainless steel.
10. The method of manufacturing the lithium electrode according to claim 1 , wherein the lithium electrode comprises
the current collector;
the lithium metal layer formed on the current collector; and
the protective layer formed on the lithium metal layer.