A Vanadium-Based Fluoroxide Cathode Material for Lithium-Ion Storage with High Energy Density

High-performance lithium-ion batteries (LIBs) are required for the rising energy storage demand, while their development depends mainly on cathode materials. Vanadium-based compounds are considered to be promising due to the feasibility of multielectron reactions arising from the rich valence states of vanadium (+2 to +5). Herein, for the first time the electrochemical properties of a vanadium-based fluoroxide, beta-KVOF3, as a cathode for LIBs, are reported. After optimization, a reversible capacity as high as 274 mAh g(-1), a stable 300 cycles lifetime, and an energy density comparable to LiFePO4 (650 vs 550 Wh kg(-1)) are achieved. Experiments and simulation study of reaction mechanism illustrate that such performance originates from the reversible V3+/V5+ redox reaction, high structural stability of beta-KVOF3, and the pseudocapacitive process during charging and discharging. This study reveals that beta-KVOF3 is a promising cathode for Li-ion storage and provides a new design idea for developing high-performance LIBs cathode materials.

Automated summary

This study reports the electrochemical properties of a vanadium-based fluoroxide, beta-KVOF3, as a cathode material for lithium-ion batteries. After optimization, the beta-KVOF3 cathode achieves high reversible capacity, stable cycle life, and comparable energy density to LiFePO4. The performance is attributed to the reversible V3+/V5+ redox reaction, high structural stability of beta-KVOF3, and the pseudocapacitive process.