Enhancing the performance of SnWO4 nanomaterials as Li-ion battery anodes

Abstract

Increasing global energy consumption trends demand efficient energy storage systems for the transition to renewable energy sources. Lithium-ion batteries have emerged as a hot research topic over the past decade due to their high energy and power densities, and the search for high-performance electrode materials has occupied the spotlight. Nanomaterials have been widely investigated as anode materials due to their high specific capacity and rate performance compared to commercial graphite (372 mAh/g). Recently, Sn-based anode materials have been of interest due to their low cost and high theoretical specific capacity (994 mAh/g) but have been held back due to their capacity fading problem arising from huge volume expansion during battery cycling. Sn-based multimetal oxides like SnWO4 are interesting due to their higher stability and theoretical capacity (850 mAh/g for α-SnWO4) compared to single metal oxides and there are only very few reports on the material. This study investigates the electrochemical performance of hydrothermally synthesized α-SnWO4 and the effect of different synthetic strategies, namely; nanocomposite formation, heteroatom doping, and surface functionalization has on it. The synthesized α-SnWO4-graphene nanocomposites, Nitrogen-doped, and surface functionalized α-SnWO4 materials successfully showed improved rate and cycling performance with respect to the pristine due to prevention of volume expansion, improved electron transport, and decreased Li+ ion diffusion path length. These results highlight the potential of α-SnWO4 as an anode material for lithium and sodium-ion batteries, which is scarcely reported in the literature.