Mechanism of Li-doping into Li4Ti5O12 negative active material for Li-ion cells by new chemical method

Li4+XTi5O12 (X > 0) negative active material has been successfully synthesized by a new chemical method for Li-doping with the catalytic function of naphthalene in Li-organic complex solution of butylmethylether (BME) or dimethoxyethane (DME) solvent. The Li-doping reaction rate constant in BME was found to be greater than that of the case of DME and its value was 5.10 and 2.78 × 10−4 S−1/2, respectively, by the calculation from the slope of distinct straight line in the relationship between ln(1/1 − Y  ) and t, where Y is molar fraction of Li-doping materials of Li7Ti5O12.