Effects of Microwave-Hydrothermal Conditions on the Purity and Electrochemical Performance of Orthorhombic LiMnO2

This paper reports the different reaction conditions to synthesize the orthorhombic LiMnO2 (hereafter referred as o-LiMnO2) and to find the economic usage of raw material to obtain the pure o-LiMnO2 with ideal electrochemical performance via effective and energy-saving microwave-hydrothermal (MH) routine. The product formation mechanism in different process is discussed in detail. X-ray diffraction patterns (XRD) indicate that the MH temperature and time are more important than the LiOH concentration of the precursors to influence the phase purity of the products. The pure phased o-LiMnO2 prepared under optimized MH condition exhibits the maximum discharge capacity of 228 mA h/g and reversible capacity of 160 mA h/g after 50 cycles at 0.1 C rate. When the current density increased to 0.2 and 0.5 C, the maximum discharge capacities of o-LiMnO2 maintain at 197 and 165 mA h/g, respectively. The o-LiMnO2 obtained in controlled MH condition shows the enhanced electrochemical performance compared with those synthesized by other method, indicating its potential application in the lithium-ion battery field.