LiAl5O8 as a potential coating material in lithium-ion batteries: a first principles study.

Coating materials in lithium-ion batteries (LIBs) have attracted extensive attention due to their ability to retard the decay of electrochemical performance in long-term cycling. Most of these coating materials, however, exhibit inferior ionic diffusivity. Herein, we report a novel coating material, LiAl5O8, which possesses a spinel-type structure. Our first principles calculation results show that the diffusion coefficient of Li ions in LiAl5O8 is over thirty orders of magnitude higher than that of Al2O3, and its electrochemical stability window is sufficiently wide, from 0.80 to 4.08 V versus Li/Li+. The facile Li ion diffusion pathways and high electrochemical stability make LiAl5O8 an effective coating material for next-generation LIBs.