Mixed lithium ion and electron conducting LiAlPO3.93F1.07-coated LiCoO2 cathode with improved electrochemical performance

•F-doped Li-ion conductive LiAlPO3.93F1.07-coated LiCoO2 is synthesized by a freeze drying method.•LAPF shows acceptable lithium ion and electron conductivity.•LAPF-coated LCO exhibits outstanding rate capability and cycle stability at 2.75-4.55 V.

LiCoO2 (LCO) has been functionally modified by mixed lithium ion and electron conducting LiAlPO3.93F1.07 (LAPF) for the first time. Due to the unique coating layer with accepted Li-ion diffusion rate and electronic conductivity, the LAPF-coated LCO exhibits outstanding rate capability and cycle stability in the voltage range of 2.75-4.55 V. This material delivered a specific capacity of 206 mAh·g− 1 up to 0.5C rate and the capacity retention was 91.7% after 50 cycles, which is a remarkable improvement comparing with uncoated LCO (34.8%). It also exhibited superior rate capability with a discharge capacity of 161.4 mAh·g− 1 at 4C. The functionalized LAPF coating technique is an efficient approach to improve the electrochemical performance of LCO and can also be referred for other layered oxide cathode materials.

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