LITHIUM METAL POWDER-CARBON POWDER COMPOSITE ANODE FOR LITHIUM SECONDARY BATTERY AND LITHIUM METAL SECONDARY BATTERY COMPRISING THE SAME

• US 20130157106A1
• Filed: 05/23/2012
• Published: 06/20/2013
• Est. Priority Date: 12/14/2011
• Status: Abandoned Application

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: Lee, Young Gi, Kim, Kwang Man, Yang, Yil Suk, Kwon, Jong Kee, Kim, Jong Dae
• Application Number:
  US13/478,581
• Publication Number:
  US 20130157106A1
• Time in Patent Office: Days
• US Class Current: 429/144
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 4/0435 Rolling or calendering
• CPC Class Codes: H01M 4/133 Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
• CPC Class Codes: H01M 4/134 Electrodes based on metals, Si or alloys
• CPC Class Codes: H01M 4/366 as layered products
• CPC Class Codes: H01M 4/382 Lithium H01M4/405 takes precedence
• CPC Class Codes: H01M 4/587 for inserting or intercalating light metals
• CPC Class Codes: H01M 4/62 Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
• CPC Class Codes: H01M 50/409 Separators, membranes or diaphragms characterised by the material
• CPC Class Codes: H01M 50/489 Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

Provided are an anode in which lithium metal powder and carbon powder are physically mixed with each other to form a composite and the composite is applied as an anode layer, and a lithium metal secondary battery including the anode. The anode of the present invention may suppress the formation of lithium dendrites and the change in volume of cells generated in a rechargeable battery which uses a lithium metal anode and significantly improve the cycle life-span of a lithium metal secondary battery by physically mixing lithium metal particles and carbon particles having an equivalent average particle diameter with each other to be applied as an anode layer.

Claims

1. An anode for a lithium metal secondary battery, comprising:

a current collector; and

an anode layer that is formed on the current collector and contains lithium metal particles and carbon particles,

wherein the anode layer comprises lithium metal particles having an average particle diameter of from 5 μ

m to 50 μ

m and carbon particles having an average particle diameter of from 5 μ

m to 30 μ

m, the lithium metal particles and the carbon particles being uniformly mixed with each other to be physically linked.

2. The anode for a lithium metal secondary battery of claim 1, wherein a mixing ratio of the lithium metal particles and carbon particles is in a range of 1-99:

99-1 (weight ratio).

3. The anode for a lithium metal secondary battery of claim 1, wherein the lithium metal particles are a core-shell structure comprising lithium metal particles and a surface protective layer which surrounds the lithium metal particles and comprises wax or silicon oil.

4. The anode for a lithium metal secondary battery of claim 1, wherein the carbon particles are at least one selected from the group consisting of graphite, hard carbon and soft carbon.

5. The anode for a lithium metal secondary battery of claim 1, wherein the anode layer is formed by coating or screen printing a slurry or paste comprising lithium metal particles and carbon particles on a current collector.

6. The anode for a lithium metal secondary battery of claim 1, wherein the anode layer further comprises a conductive agent.

7. A lithium metal secondary battery, comprising:

an anode comprising an anode layer in which lithium metal particles having an average particle diameter of from 5 μ

m to 50 μ

m and carbon particles having an average particle diameter of from 5 μ

m to 30 μ

m are uniformly mixed with each other to be physically linked;

a cathode;

a separator interposed between the cathode and the anode; and

an electrolyte injected therebetween.

8. The lithium metal secondary battery of claim 7, wherein the cathode comprises, as a cathode active material, a lithium-containing metal composite oxide selected from the group consisting of olivine (LiFePO₄), lithium cobalt oxide (LiCoO₂), lithium nickel oxide (LiNiO₂) and lithium manganese oxide (LiMn₂O₄), a mixture of the lithium-containing metal composite oxide, a solid solution of the lithium-containing metal composite oxide, or a material with aluminum, iron, copper, titanium, and magnesium substituted in the solid solution.

9. The lithium metal secondary battery of claim 7, wherein the separator is a polyethylene-based single film or a multilayer film of polyethylene and polypropylene.

10. The lithium metal secondary battery of claim 7, wherein the electrolyte comprises a lithium salt and an organic solvent and the organic solvent is at least one solvent selected from the group consisting of ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, tetrahydrofuran, 2-methyltetrahydrofuran, dimethoxyethane, methyl formate, ethyl formate, and γ

-butyrolactone.

11. The lithium metal secondary battery of claim 10, wherein the lithium salt is at least one selected from the group consisting of lithium perchlorate (LiClO₄), lithium triflate (LiCF₃SO₃), lithium hexafluorophosphate (LiPF₆), lithium tetrafluoroborate (LiBF₄), and lithium trifluoromethanesulfonyl imide (LiN(CF₃SO₂)₂).