Effects of preparation conditions on the electrochemical and morphological characteristics of Li₄Ti₅O₁₂ powders prepared by spray pyrolysis

Li₄Ti₅O₁₂ anode powders were prepared by post-treatment of the precursor powders obtained by spray pyrolysis at various preparation conditions. The precursor powders had fine size, narrow size distribution, dense inner structure and homogeneous composition when the flow rate of the carrier gas and the preparation temperature were 10 l min^-1 and 800 °C. The spherical shapes of the precursor powders obtained at the optimum preparation conditions maintained after post-treatment at a temperature of 800 °C. The mean sizes of the Li₄Ti₅O₁₂ powders were controlled by changing the concentrations of the spray solution. The initial discharge capacities and cycle properties of the Li₄Ti₅O₁₂ powders were strongly affected by the preparation temperatures of the precursor powders. The optimum preparation temperature of the precursor powders was 800 °C when the flow rate of the carrier gas was 10 l min^-1. The discharge capacities and cycle properties of the Li₄Ti₅O₁₂ powders were not affected by flow rates of the carrier gas. The Li₄Ti₅O₁₂ powders had good cycle properties irrespective of the concentrations of the spray solution. However, the Li₄Ti₅O₁₂ powders obtained from the spray solutions with high concentration above 0.5 M had high discharge capacities than those obtained from the spray solutions with low concentration below 0.1 M.