Controllable synthesis of cube-like ZnSnO3@TiO2 nanostructures as lithium ion battery anodes

Abstract

ZnSnO₃ is an attractive anode material for lithium ion batteries because of its higher theoretical capacity compared to the state-of-the-art carbonaceous counterpart. The main challenges associated with ZnSnO₃ anodes are structural degradation and instability of the solid-electrolyte interphase, caused by the large volume change during cycling. Herein, we propose a hierarchical structured ZnSnO₃@TiO₂ nanocomposite anode that tackles this problem. The as-prepared, core–shell, cube-like anode material exhibits enhanced capacity and cycling property. In proof-of-concept experiments, this hierarchical heterostructure shows a high initial discharge capacity of 1590 mA h g⁻¹ at 100 mA g⁻¹ and retained 780 mA h g⁻¹ after 200 cycles, which is much better than the anodes made of pure ZnSnO₃ nanomaterials. The enhanced cycle life can be attributed to the reductive volume expansion during the repeated charge–discharge cycles, owing to the hierarchical porous three-dimensional structure and TiO₂ shell as well as the synergistic effects of ZnSnO₃ and TiO₂.