Preparation, Microstructure And Electrochemical Properties Of Spherical-Like Orthorhombic Limno2

Spherical-like morphology orthorhombic LiMnO2 (So-LiMnO2) powders were prepared using spherical MnCO3 precursors obtained by a carbonate co-precipitation method. The materials were characterized using XRD, SEM and low temperature nitrogen adsorption desorption. Non-spherical orthorhombic LiMnO2(No-LiMnO2) powders were also studied for comparison. The characteristics of o-LiMnO2 such as the stacking faults, crystallization, particles morphology and size were significantly dependent on the microstructure of precursors. The electrochemical performances of o-LiMnO2-based cathodes were tested during 80 cycles. The So-LiMnO2 cathode had a maximum capacity of 152 mAh.g(-1) on the 15 h cycle, and exhibited an average capacity decay of approximately 0.58 mAh.g(-1) per cycle. By contrast, the No-LiMnO2 sample had a maximum capacity of 128 mAh.g(-1) on the 38(th) cycle, and experienced an average capacity decay of 1.24 mAh.g(-1) per cycle. TEM observation and EDS analysis confirmed that So-LiMnO2 particle, agglomerated by primary particles, could reduce the erosion of positive material by electrolytes and the dissolution of manganese, which results in the enhanced electrochemical cycleability.