Preparation of Cu[sub 6]Sn[sub 5]-Encapsulated Carbon Microsphere Anode Materials for Li-ion Batteries by Carbothermal Reduction of Oxides

Abstract

A novel process was proposed to prepare Cu 6 Sn 5 -encapsulated carbon microsphere (CM/Cu 6 Sn 5 ) anode materials for the first time through inverse emulsion polymerization of resorcinol-formaldehyde (RF) performed in the presence of CuO and SnO 2 powders (1.2:1 molar ratio), followed by carbonization and carbothermal reduction in an inert atmosphere. The oxides powder were encapsulated within the carbon gel microspheres and the elemental Sn and Cu were reduced from their oxides by the carbonized RF gel to form crystalline Cu 6 Sn 5 alloy within carbon microspheres. The CM/Cu 6 Sn 5 presented much better cycleability than that of Cu 6 Sn 5 alloy powder. The proposed process paves an effective way to prepare high-performance alloy/C microspheres composite anode materials for lithium-ion batteries. © 2006 The Electrochemical Society. All rights reserved.