The Li and Mn-rich layered composites represented by Li 2 MnO 3 –LiMO 2 has been attracting great interests owing to its exceptional high capacity (⩾250mAhg −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 Al 2 O 3 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.