High-Performance Low-Temperature Li+ Intercalation in Disordered Rock-Salt Li–Cr–V Oxyfluorides

Abstract

At −10 °C and 26 mA g−1, Li2Cr0.2V0.8O2F can deliver a stable high capacity of 250 mAh g−1 (or 690 Wh kg−1) over 60 cycles. Even at −20 °C and a current density of 106 mA g−1, it still delivers a steady capacity and specific energy of about 160 mAh g−1 and 400 Wh kg−1, respectively, over 100 cycles. Superior performance of Li2Cr0.2V0.8O2F over Li2VO2F and Li2CrO2F is related to its structural stability and electronic properties.