High rate capability and long cycle stability of TiO2−δ–La composite nanotubes as anode material for lithium ion batteries

Abstract

TiO2−δ–La composite nanotubes are prepared by heating the ethanol solution of La(NO3)3⋅6H2O which is introduced into nanotube titanium acid at pre-set temperature. The effect of La dosage on the microstructure and electrochemical properties of as-fabricated TiO2−δ–La composite nanotubes is investigated. Results indicate that La3+ can be trapped in the internal/external surfaces and the interlayer space of nanotubes. All of these help to retain the nanotubular morphology and layered structure during the dehydration process. Ti3+ defects generated by the dehydration of nanotube titanium acid can be stabilized by the formed Ti–O–La bond. So, as-fabricated TiO2−δ–La composite nanotubes samples exhibit markedly improved electrochemical properties than pristine TiO2. Particularly, the electrode made of TiO2−δ–La composite nanotubes containing 5% La element (mass fraction) has a high capacity of 142mAhg−1 at a charge/discharge rate of 20C rate and a capacity retention of 87% after 1000 cycles at 10C, showing superior electrochemical performance and great potential as an anode material for high-rate lithium-ion batteries.