Co-Modification of commercial TiO(2) anode by combining a solid electrolyte with pitch-derived carbon to boost cyclability and rate capabilities

The bad electrochemical performance circumscribes the application of commercial TiO(2) (c-TiO(2)) anodes in Li-ion batteries. Carbon coating could ameliorate the electronic conductivity of TiO(2), but the ionic conductivity is still inferior. Herein, a co-modification method was proposed by combining the solid electrolyte of lithium magnesium silicate (LMS) with pitch-derived carbon to concurrently meliorate the electronic and ionic conductivities of c-TiO(2). The homogeneous mixtures were heated at 750 °C, and the co-modified product with suitable amounts of LMS and carbon demonstrates cycling capacities of 256.8, 220.4, 195.9, 176.4, and 152.0 mA h g(−1) with multiplying current density from 100 to 1600 mA g(−1). Even after 1000 cycles at 500 mA g(−1), the maintained reversible capacity was 244.8 mA h g(−1). The superior rate performance and cyclability correlate closely with the uniform thin N-doped carbon layers on the surface of c-TiO(2) particles to favor the electrical conduction, and with the ion channels in LMS as well as the cation exchangeability of LMS to facilitate the Li(+) transfer between the electrolyte, carbon layers, and TiO(2) particles. The marginal amount of fluoride in LMS also contributes to the excellent cycling stability of the co-modified c-TiO(2).