Studies of the electrochemical behavior of LiNi_0.80Co_0.15Al_0.05O₂ electrodes coated with LiAlO₂

In this paper, we studied the influence of LiAlO₂ coatings of 0.5, 1 and 2 nm thickness prepared by Atomic Layer Deposition onto LiNi_0.8Co_0.15Al_0.05O₂ electrodes, on their electrochemical behavior at 30 and 60°C. It was demonstrated that upon cycling, 2 nm LiAlO₂ coated electrodes displayed ∼3 times lower capacity fading and lower voltage hysteresis comparing to bare electrodes. We established a correlation among the thickness of the LiAlO₂ coating and parameters of the self-discharge processes at 30 and 60°C. Significant results on the elevated temperature cycling and aging of bare and LiAlO₂ coated electrodes at 4.3 V were obtained and analyzed for the first time. By analyzing of X-ray diffraction patterns of bare and 2 nm coated LiNi_0.8Co_0.15Al_0.05O₂ electrodes after cycling, we concluded that cycled materials preserved their original structure described by R-3m space group and no additional phases were detected.