Impact of Al Doping and Surface Coating on the Electrochemical Performances of Li-Rich Mn-Rich Li1.11Ni0.33Mn0.56O2 Positive Electrode Material

Abstract

Li and Mn-rich positive electrode materials, Li[LixTM1−x]O2 (TM = Ni, Co, and Mn), with a single-phase layered structure have been considered for use in next-generation Li-ion batteries for electric vehicles and many advanced applications. Despite their high specific capacity >250 mAh g−1, the commercialization of these materials is hindered by poor rate capability and voltage decay originating from transition metal migration to the lithium layer. Herein, the effect of aluminum doping and aluminum oxide surface coating on the structural and electrochemical performances of Co-free Li1.11Ni0.33Mn0.56O2 was studied. All synthesized materials were single phase with a similar morphology and amount of Ni in the Li layers. Even though the discharge capacity and capacity retention were slightly improved, there was no significant impact of the addition of Al on the rate of voltage fading during charge-discharge cycling as previously reported.