Studies of the Electrochemical Behavior of LiNi0.80Co0.15Al0.05O2Electrodes Coated with LiAlO2

The goal of this work was to understand the influence of nano-sized LiAlO2 coatings prepared by Atomic Layer Deposition (ALD) onto LiNi0.8Co0.15Al0.05O2 (NCA) electrodes on their electrochemical behavior at 30 and 60C in terms of the potential windows, capacity fade, impedance characteristics, and the self-discharge. LiAlO2 coatings of 0.5, 1 and 2 nm thickness were effectively deposited directly onto LiNi0.8Co0.15Al0.05O2 electrodes using ALD technique. The novelty of the present study is that, for the first time, we obtained and analyzed significant results on the elevated temperature aging (the self-discharge) of bare and LiAlO2 coated electrodes at 4.3 V. 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 [1]. We established a correlation among the thickness of the LiAlO2 coating and parameters of the self-discharge processes at 30 and 60 C. These results were obtained for the first time. By analyzing of X-ray diffraction patterns of bare and 2 nm coated LiNi0.8Co0.15Al0.05O2 electrodes after cycling, we concluded that cycled materials preserved their original structure described by R-3m space group and no additional phases were detected.