Combustion synthesis of high-performance Li₄Ti₅O₁₂ for secondary Li-ion battery

Spinel Li₄Ti₅O₁₂ was synthesized by a simple glycine-nitrate auto-combustion by applying aqueous medium and constricting the reactions in the pores of cellulose fibers. The products from the auto-combustion and further calcination at various temperatures were characterized by XRD, SEM, BET surface area and TEM examinations. Pure phase and well-crystallized nano-Li₄Ti₅O₁₂ oxides were obtained at a calcination temperature of 700 °C or higher. The 700 °C calcined one shows the best and high electrochemical performance, which reached a capacity of ∼125 mAh/g at 10 C discharge rate with fairly stable cycling performance even at 40 °C. Electrochemical impedance spectroscopy tests demonstrated that the surface reaction kinetics of Li₄Ti₅O₁₂ was improved significantly with the increase of its electronic conductivity.