Improving Lithium‐Ion Half‐/Full‐Cell Performance of WO3‐Protected SnO2 Core‐Shell Nanoarchitectures

Abstract Anodes derived from SnO 2 offer a greater specific capacity comparative to graphitic carbon in lithium‐ion batteries (LIBs); hence, it is imperative to find a simple but effective approach for the fabrication of SnO 2 . The intelligent surfacing of transition metal oxides is one of the favorite strategies to dramatically boost cycling efficiency, and currently most work is primarily aimed at coating and/or compositing with carbon‐based materials. Such coating materials, however, face major challenges, including tedious processing and low capacity. This study successfully reports a new and simple WO 3 coating to produce a core‐shell structure on the surface of SnO 2 . The empty space permitted natural expansion for the SnO 2 nanostructures, retaining a higher specific capacity for over 100 cycles that did not appear in the pristine SnO 2 without WO 3 shell. Using WO 3 ‐protected SnO 2 nanoparticles as anode, a coin half‐cell battery was designed with Li‐foil as counter‐electrode. Furthermore, the anode was paired with commercial LiFePO 4 as cathode for a coin‐type full cell and tested for lithium storage performance. The WO 3 shell proved to be an effective and strong enhancer for both current rate and specific capacity of SnO 2 nanoarchitectures; additionally, an enhancement of cyclic stability was achieved. The findings demonstrate that the WO 3 can be used for the improvement of cyclic characteristics of other metal oxide materials as a new coating material.