Functional behavior of AlF<sub>3</sub> coatings for high-performance cathode materials for lithium-ion batteries

In response to the ever worsening of the environment by consumption of fossil fuels, energy storage systems like lithium-ion batteries that offer high energy efficiency have evoked a great interest as power sources from portable electronics to electric vehicles. However, the improvement of calendar and cycling life together with safety issues require sophisticated technology to prevent degradation mechanisms. The surface modification of the electrode materials is part of the solution. In this paper, the surface coverage of cathode materials by aluminum fluoride is reviewed. The effect of AlF₃ coating on electrochemical performance is examined at various deposit amounts with a comparison of the capacity retention and cycling stability of the different systems proposed in the literature.