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 Li2SnO3 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 Li2O matrix. Due to the buffer role of the Li2O matrix, the reversibility of the secondary Li–Sn alloy electrode is largely secured.