Synthesis and electrochemical performances of Li4Ti4.95Zr0.05O12/C as anode material for lithium-ion batteries

Spinel Li4Ti5 -aEuro parts per thousand x Zr (x) O-12/C (x = 0, 0.05) were prepared by a solution method. The structure and morphology of the as-prepared samples were characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The electrochemical performances including charge-discharge (0-2.5 V and 1-2.5 V), cyclic voltammetry, and ac impedance were also investigated. The results revealed that the Li4Ti4.95Zr0.05O12/C had a relatively smaller particle size and more regular morphology than that of Li4Ti5O12/C. Zr4+ doping enhanced the ability of lithium-ion diffusion in the electrode. It delivered a discharge capacity 289.03 mAh g(-1) after 50 cycles for the Zr4+-doped Li4Ti5O12/C while it decreased to 264.03 mAh g(-1) for the Li4Ti5O12/C at the 0.2C discharge to 0 V. Zr4+ doping did not change the electrochemical process, instead enhanced the electronic conductivity and ionic conductivity. The reversible capacity and cycling performance were effectively improved especially when it was discharged to 0 V.