Microstructure effect on the electrochemical property of Li4Ti5O12 as an anode material for lithium-ion batteries

Porous (P-) and dense (D-) lithium titanate (Li4Ti5O12) powders as an anode material for lithium-ion batteries have been synthesized by spray drying followed by solid-state calcination. Electrochemical testing results showed that the discharge capacities of P-Li4Ti5O12 are 144 mAh/g, 128 mAh/g and 73 mAh/g at the discharging rate of 2C, 5C and 20C, respectively (cut-off voltages: 0.5-2.5 V). The corresponding values for D-Li4Ti5O12 are 108 mAh/g, 25 mAh/g and 17 mAh/g. The higher capacity of the P-Li4Ti5O12 at high charge/discharge rates was attributed to the shorter transport path of Li ions and higher electronic conductivity in the P-Li4Ti5O12 as a result of its smaller primary particle size and higher surface area compared with those of the D-Li4Ti5O12.