Electrochemical performance and lithium-ion insertion/extraction mechanism studies of the novel Li2ZrO3 anode materials

Li2ZrO3 anode materials were prepared by the conventional solid-state reaction. The crystal structure has been determined by X-ray diffraction. Electrochemical tests show that Li2ZrO3 anode materials process a excellent cycle performance and rate capability due to the good structural stability and high lithium diffusion coefficients. For the Li2ZrO3 anode material, the change of the unit cell volume is only ∼0.3% at discharge or charge process. Except for the first several cycles, the coulombic efficiency of the Li2ZrO3 electrode was nearly 100% at a discharge/charge rate of 0.3 C. The lithium diffusion coefficients of Li2ZrO3 for the reduction and oxidation process are calculated to be 3.165 × 10−6 and 1.919 × 10−6 cm2 s−1 respectively which is much higher than that of the Li4Ti5O12 anode material (about 10−9 to 10−13 cm2 s−1). In situ XRD results, combined the sloping character of the charge/discharge voltage profiles and the lithium ion diffusion controlled mechanism in the charge and discharge process, show that the insertion/extraction mechanism of Li+ for Li2ZrO3 can be interpreted as a solid-solution behavior.