Li2SnO3 derived secondary Li-Sn alloy electrode for lithium-ion batteries

As a possible high-capacity Li-ion battery anode material, Li2SnO3 was prepared via a solid-state reaction route and a sol-gel route, separately. Its electrochemical performance was tested in coin-type cells with metallic Li as the counter electrode. The results show that the sol-gel derived Li2SnO3 has uniform nano-sized particles (200-300 nm) and can deliver a better reversible capacity (380 mAh/g after 50 cycles in the voltage window of 0-1 V) than that from the solid-state reaction route. The characterizations by means of galvanostatic cycling, cyclic voltammetry and ex situ X-ray diffraction indicate that the electrochemical process of the LiSnO3 lithiation proceeds with an initial structural reduction of the composite oxide into Sn-metal and Li2O followed by a reversible Li-Sn alloy formation in the LiO matrix. Due to the buffer role of the LiO matrix. the reversibility, of the secondary Li-Sn alloy electrode is largely secured. (c) 2005 Elsevier B.V. All rights reserved.