Anode active material for lithium secondary batteries and method for manufacturing same
Disclosed are an anode active material for lithium secondary batteries and a method for manufacturing same, the anode active material comprising: a core part including a carbon-silicon complex and having a cavity therein; and a coated layer which is formed on the surface of the core part and includes a phosphor-based alloy.
1. A method of manufacturing an anode active material for the lithium secondary battery, the method comprising,
treating a silicon polymer particle with a metal chloride solution to prepare the silicon polymer particle with a metal catalyst supported on a surface;
dispersing the silicon polymer particle with the metal catalyst supported on the surface in a plating bath filled with a plating solution containing a metal ion for a phosphorous-based alloy and phosphoric acid;
heating the bath to form a phosphorous (P)-based alloy surface-coated silicon polymer particle; and
carbonizing the phosphorous (P)-based alloy surface-coated silicon polymer particle by heat treatment in a range of 800 to 1200° C. in a reducing atmosphere, thereby forming a core including a carbon-silicon composite and having a cavity formed inside.
2. The method of manufacturing the anode active material for the lithium secondary battery according to claim 1 , wherein the silicon polymer particle is polysiloxane, polysilane, and polycarbosilane.
3. The method of manufacturing the anode active material for the lithium secondary battery according to claim 1 , wherein the metal chloride solution is one that metal chloride selected from PdCl 2 , SnCl 2 , and CuCl 2 is dissolved in an aqueous solution of nitrohydrochloric acid or hydrochloric acid, or in a polar organic solvent of dimethylformamide (DMF), hexamethylphosphoramide (HMPA), dimethylacetamide (DMA) or dimethylsulfoxide (DMSO).
4. The method of manufacturing the anode active material for the lithium secondary battery according to claim 1 , wherein the metal ion for the phosphorous-based alloy is one type of ion selected from Ni 2+ , Cu 2+ , Ti 4+ ,Al 3+ ,Cr 2+ ,Cr 3+ ,Cr 6+ , Mn 2+ , Mn 3+ , Mn 4+ , Fe 2+ , Fe 3+ , Co 2+ , Co 3+ , Zn 2+ , Ga 3+ , Ge 4+ , As 4+ , Pd. 2+ , Ag + , In 2+ , In 3+ , Sn 2+ , and W 6+ , or mixtures thereof.