Sol-gel preparation and electrochemical properties of La-doped Li4Ti5O12 anode material for lithium-ion battery

A sol-gel method using Ti(OC4H9)(4), LiCH3COO center dot 2H(2)O, and La(NO3)(3)center dot 6H(2)O as starting materials and ethyl acetoacetate as chelating agent to prepare pure and lanthanum (La)-doped Li4Ti5O12 is reported. The structure and morphology of the active materials characterized by powder X-ray diffraction and scanning electron microscopy analysis indicate that doping with a certain amount of La3+ does not affect the structure of Li4Ti5O12, but can restrain the agglomeration of the particles during heat treatment. The electrochemical properties measured by cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic charge-discharge cycling tests show that La-doped Li4Ti5O12 presents a much improved electrochemical performance due to a decrease in charge transfer resistance. At current densities of 1 and 5 C, the La-doped Li4Ti5O12 exhibits excellent reversible capacities of 156.16 and 150.79 mAh g(-1), respectively. The excellent rate capability and good cycling performance make La-doped Li4Ti5O12 a promising anode material for lithium-ion batteries in energy storage systems.