COMPOSITE PARTICLES, METHOD FOR PRODUCING SAME, ELECTRODE MATERIAL FOR SECONDARY BATTERIES, AND SECONDARY BATTERY

摘要

Provided is positive electrode material for a highly safe lithium-ion secondary battery that can charge and discharge a large current while having long service life. Disclosed are composite particles comprising: particles of lithium-containing phosphate; and carbon coating comprising at least one carbon material selected from the group consisting of (i) fibrous carbon material, (ii) chain-like carbon material, and (iii) carbon material produced by linking together fibrous carbon material and chain-like carbon material, wherein each particle is coated with the carbon coating. The fibrous carbon material is preferably a carbon nanotube with an average fiber size of 5 to 200 nm. The chain-like carbon material is preferably carbon black produced by linking, like a chain, primary particles with an average particle size of 10 to 100 nm. The lithium-containing phosphate is preferably LiFePO 4 , LiMnPO 4 , LiMn X Fe (1-X) PO 4 , LiCoPO 4 , or Li 3 V 2 (PO 4 ) 3 .