Scalable synthesis of Ti3+ self-doped Li4Ti5O12 microparticles as an improved performance anode material for Li-ion batteries

Abstract A series of microparticles Ti 3+ self-doped Li 4 Ti 5 O 12 spinel particles were first synthesized via a facile one-step solid-phase sintering process. In the synthes process, the introduction of coarse titanium powder as a reducing agent improves the electrochemical performance of Li 4 Ti 5 O 12 as anode material for lithium ion batteries (LIBs). Successful doping of the Ti 3+ species and/or oxygen vacancies onto the LTO surface was confirmed by X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. In the solid phase synthesis of lithium titanate, the Ti 3+ content could be controlled by adjusting the amount of titanium powder. The addition of titanium powder resulted in the formation of Ti 3+ self-doped Li 4 Ti 5 O 12 microparticles, which is responsible for the enhanced rate performance and cyclic stability. With the increase of Ti 3+ content, the electrochemical performance of Ti 3+ self-doped Li 4 Ti 5 O 12 sample could become more rising. A high capacity retention of 96.9% can be obtained at 2 C after 400 cycles. What is more, at charge/discharge rates of 0.5, 1, 2, 5 and 10 C, the discharge capacities of the LTO--15% electrode were 143.4, 136.4, 132.7, 127.5 and 116.5 mAh g −1 , respectively.