Partially amorphous vanadium oxysulfide for achieving high-performance Li-ion batteries.

Vanadium-based materials exhibit a high theoretical capacity and diverse valence states, rendering them promising candidate anodes for lithium-ion batteries (LIBs). However, the cycling and rate performance are limited by their weak structural stability and electrical conductivity. Herein, a rational amorphization strategy has been developed to construct dual-anion vanadium oxysulfide nanoflowers (VSO NFs) with partial amorphous components and abundant oxygen vacancies as anode material for LIBs. Both experimental and theoretical calculations results suggest that the introduction of amorphous components and oxygen vacancies significantly improves its electronic conductivity and provides abundant channels and active sites for the movement of Li ions. As expected, the VSO NFs electrode can provide an ultrahigh capacity (672.3 mAh/g at 0.1 A/g) and excellent rate performance (433.1 mAh/g at 2.0 A/g), as well as remarkable cyclic stability (361.7 mAh/g at 2.0 A/g after 600 cycles). Finally, the assembled VSO NFs//LiFePO full battery also shows outstanding rate capability and cycling life. Therefore, this amorphous strategy can serve as a guideline for manufacturing high-performance anode materials in electrochemical energy-storage fields.