Vapour solid reaction growth of SnO2 nanorods as an anode material for Li ion batteries

Via a vapour-solid reaction growth (VSRG) pathway, phase-segregated SnO2 nanorods (NRs, length 1-2 mu m and diameter 10-20 nm) were developed in a matrix of CaCl2 salt by reacting CaO particles with a flowing mixture of SnCl4 and Ar gases at elevated temperatures. The SnO2 NRs were investigated as a potential anode material for Li-ion batteries (LIBs). A half-cell constructed from the as-fabricated SnO2 electrode and a Li foil exhibited a reversible capacity 435 mA h g(-1) after one hundred cycles at a current density of 100 mA g(-1) (0.13 C). The SnO2 NRs exhibited much better Li storage properties, higher reversible capacity and cyclic capacity retention after extended cycling, than commercial SnO2 particles did. The improved electrochemical performance is attributed to the presence of an inactive amorphous byproduct matrix, which contains Li2O, the decomposed electrolyte, and the solid electrolyte interphase (SEI), among the reduced NRs. The matrix probably buffered and reduced the stress caused by the volume change of the electrode during the charge-discharge cyclings.