High-performance Li4Ti5−xVxO12 (0 ≤ x ≤ 0.3) as an anode material for secondary lithium-ion battery

Abstract Powders of spinel Li 4 Ti 5− x V x O 12 (0 ≤  x  ≤ 0.3) were successfully synthesized by solid-state method. The structure and properties of Li 4 Ti 5− x V x O 12 (0 ≤  x  ≤ 0.3) were examined by X-ray diffraction (XRD), Raman spectroscopy (RS), scanning electronic microscope (SEM), galvanostatic charge–discharge test and cyclic voltammetry (CV). XRD shows that the V 5+ can partially replace Ti 4+ and Li + in the spinel and the doping V 5+ ion does almost not affect the lattice parameter of Li 4 Ti 5 O 12 . Raman spectra indicate that the Raman bands corresponding to the Li–O and Ti–O vibrations have a blue shift due to the doping vanadium ions, respectively. SEM exhibits that Li 4 Ti 5− x V x O 12 (0.05 ≤  x  ≤ 0.25) samples have a relative uniform morphology with narrow size distribution. Charge–discharge test reveals that Li 4 Ti 4.95 V 0.05 O 12 has the highest initial discharge capacity and cycling performance among all samples cycled between 1.0 and 2.0 V; Li 4 Ti 4.9 V 0.1 O 12 has the highest initial discharge capacity and cycling performance among all samples cycled between 0.0 and 2.0 V or between 0.5 and 2.0 V. This excellent cycling capability is mainly due to the doping vanadium. CV reveals that electrolyte starts to decompose irreversibly below 1.0 V, and SEI film of Li 4 Ti 5 O 12 was formed at 0.7 V in the first discharge process; the Li 4 Ti 4.9 V 0.1 O 12 sample has a good reversibility and its structure is very advantageous for the transportation of lithium-ions.