Competitive Redox Chemistries in Vanadium Niobium Oxide for Ultrafast and Durable Lithium Storage

Abstract

Highlights The over-reduction from Nb5+ to Nb3+ in the lithiation process have been demonstrated to be the critical reason for the capacity decay of Nb2O5 for the first time. A novel competitive redox strategy has been proposed to suppress the over-reduction of Nb5+ to Nb3+, which can be achieved by the incorporation of vanadium to form a new rutile VNbO4 anode. The performance of VNbO4 anode designed in this study stands among the best in cycle stability.

Keywords

• Niobium pentoxide
• Capacity decay
• Over-reduction
• Vanadium niobium oxide
• Lithium-ion capacitor