Ultra-thin Al2O3 coating on the acid-treated 0.3Li(2)MnO(3)center dot 0.7LiMn(0.60)Ni(0.25)Co(0.15)O(2) electrode for Li-ion batteries

Abstract

The Li and Mn-rich layered composites represented by Li2MnO3-LiMO2 has been attracting great interests owing to its exceptional high capacity (>= 250 mA h g(-1)) and enhanced structural stability. In order to improve the initial coulombic efficiency and cyclability of the composites, the material has been activated by an acid-treatment and coated with an Al2O3 using an atomic layer deposition (ALD). The acid-treated electrode showed a higher discharge capacity than the as-prepared electrode. The alumina-coated electrode provided an improved specific capacity of the electrode but also cycling stability, when compared with the bare electrode. The electrode coated with the alumina could lead to a decrease in undesirable reactions, thereby acting as a stable protecting layer that could quickly transport Li+ ions during charge and discharge process.