Defective mesoporous Li4Ti5O12−y: An advanced anode material with anomalous capacity and cycling stability at a high rate of 20 C

Abstract

How to obtain an excellent capacity and cycling stability of electrodes that work at high rates is now challenging the development of lithium-ion batteries. Herein, we initiate a facile solvothermal method to prepare defective mesoporous Li4Ti5O12−y as an anode material with an improved high-rate performance for lithium-ion batteries. The high-rate performance for the resultant anode is represented by a discharge capacity of 139mAhg−1 at a high rate of 20C with a capacity retention of 91.4% over 300 cycles. Different from the strategies popularly used in literature, the current approach does not rely on any aids from conductive layers or foreign dopants, but takes advantages of the unique features of a defective mesoporous structure with oxygen vacancies and Ti3+–O2−–Ti4+ pairs. These features enable an improved intrinsic electronic conductivity, which leads to a high-rate performance and cycling stability superior to the stoichiometric mesoporous counterpart when annealing in air. The defective mesoporous Li4Ti5O12−y is therefore demonstrated to be a promising advanced anode material for high-rate lithium-ion batteries.