SnO2/WO3 core-shell nanorods and their high reversible capacity as lithium-ion battery anodes

WO3 nanorods are uniformly coated with SnO2 nanoparticles via a facile wet-chemical route. The reversible capacity of SnO2/WO3 core-shell nanorods is 845.9 mA h g(-1), higher than that of bare WO3 nanorods, SnO2 nanostructures, and traditional theoretical results. Such behavior can be attributed to a novel mechanism by which nanostructured metallic tungsten makes extra Li2O (from SnO2) reversibly convert to Li+. This mechanism is confirmed by x-ray diffraction results. Our results open a way for enhancing the reversible capacity of alloy-type metal oxide anode materials.