Ultrathin TiO2 rutile nanowires enable reversible Mg-ion intercalation

Crystalline ultrathin TiO2 nanowires with oriented configurations are promising for high-performance energy storage and conversion devices. In this work, we use hierarchical microspheres constructed from radially oriented single-crystalline TiO2 nanowires as electrode materials for reversible Mg-ion intercalation. The obtained mesoporous TiO2 nanowires deliver a capacity of 118 mA h g (1) at 20 mA/g current rate. The ultra small size of TiO2 nanocrystalline is beneficial for reaction kinetics, enhance the bulk intercalation of Mg ions, which remarkably increases storage capacity of TiO2. The discharge capacity over 100 cycles remains 105.2 mA h g (1), demonstrating the superiority of this material structure and its potential in magnesium ion batteries. (C) 2019 Elsevier B.V. All rights reserved.