The synergistic effect of inert oxide and metal fluoride dual coatings on advanced cathode materials for lithium ion battery applications

Abstract

The effect of Al₂O₃/LiF dual coatings on the electrochemical performance of over-lithiated layered oxide (OLO) has been investigated. A uniform coating of Al₂O₃ and LiF is obtained on the surface of the layered pristine material. The OLO with a dual Al₂O₃/LiF coating with a ratio of 1 : 1.5 exhibits excellent electrochemical performance. An initial discharge capacity of 265.66 mA h g⁻¹ is obtained at a C-rate of 0.1C. This capacity is approximately 15 mA h g⁻¹ higher than that of pristine OLO. The capacity retention (92.8% at the 50th cycle) is also comparable to that of pristine OLO (91.4% at the 50th cycle). Coating the cathode with a dual layer comprising Al₂O₃ and LiF leads to improved charging and discharging kinetics, and prevents direct contact between the cathode and the electrolyte.