SnO2 and TiO2-supported-SnO2 lithium battery anodes with improved electrochemical performance

Abstract

Li-ion battery anodes made of SnO2 nanoparticles and a TiO2-supported SnO2 nanocomposite formed of equimolar amounts of the Sn and Ti oxides were investigated, respectively. By limiting the voltage window of the charge/discharge cycles to the range 50 mV–1.0 V, both the SnO2-based anode and the SnO2/TiO2-based anode show improved cycling stability. Compared to the SnO2 nanoparticle based anodes, the TiO2-support-SnO2 nanocomposite anodes exhibit better cyclability and higher Coulombic efficiency. During the first lithiation process, Li+ conducting LixTiO2 is formed in the SnO2/TiO2 composite, which structurally/mechanically supports the electrode. The anode made of amorphous TiO2-cassiterite SnO2 retained a reversible capacity of ∼500 mAh g−1 (based on the weight of SnO2) or ∼320 mAh g−1 (based on the weight of SnO2/TiO2) at 0.2 C after 100 cycles and at a rate as fast as 5 C retained a stable reversible capacity of ∼340 mAh g−1 (based on the weight of SnO2) or ∼220 mAh g−1 (based on the weight of SnO2/TiO2).