Facile synthesis of TiO2/WO3 nanocomposites and the electrochemical lithiation/delithiation activity

TiO2 is an attractive anode material for lithium ion batteries (LIBs). However, the low theoretical capacity and poor conductivity greatly hinder its potential applications. In this work, TiO2/WO3 nanocomposites (NCs) are successfully synthesized by a one-step method of DC arc-discharge plasma. It is found that TiO2 and WO3 grains are closely combined into bigger particles by chemical/physical adherence, quite different from common connection ways of coating or mechanical mixing. In bigger particles, the combination of WO3 and TiO2 grains can reinforce their electrochemical activities, shorten the diffusion distance of Li+ ions inside, and effectively avoid side reactions happening at the interface between two phases. Moreover, the WO3 phase with a theoretical specific capacity of 694 mAh g−1 makes positive contributions to the TiO2-based materials in the capacity and conductivity. The TiO2/WO3 NCs electrode delivers a stable discharge specific capacity of 557.2 mAh g−1 at a current density of 0.1 A g−1 over 100 cycles, which recovers to 664.1 mAh g−1 after suffering from intense current impacts up to 2.0 A g−1.