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

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