One-pot synthesis of aluminum oxide coating and aluminum doping on lithium manganese oxide nanoparticles for high performance energy storage system

In the present study, in order to demonstrate the one-pot synthesis of aluminum oxide (Al₂O₃) coating and aluminum doping, we synthesized aluminum oxide (Al₂O₃)-coated LiAl_xMn_2-xO₄ (LAMO) NPs using a sequential process of the as-spun nanofiber templates, chemical precipitation, and calcination as a cathode material in lithium ion batteries (LIBs). To find the optimum condition of Al₂O₃ coating layer and Al doping, we performed the simple calcination methods at 300 °C using the Al(OH)₂-coated LMO NPs. The resultant Al₂O₃-coated LAMO NPs exhibited the highest capacity of 111.1 mAh g⁻¹ with the capacity retention of 94.4% after 90 cycles at 1 C, excellent rate performance, and the highest high-rate capacity of 81.4 mAh g⁻¹ at 10 C as compared to bare LMO NPs without Al₂O₃ coating and Al(OH)₂-coated LMO NPs without calcination. The improved electrochemical performance can be defined by the co-effect of Al₂O₃ coating and Al doping on bare LMO NPs. The former is related to cycle stability that increased due to the prevention of volume expansion and Mn dissolution as a physical buffer layer. The latter is related to high-rate performance improved due to the enhanced bonding energy of Al–O bond. Therefore, it can be concluded that Al₂O₃-coated LAMO NPs are promising candidate cathode materials for high-performance LIBs.