Fabricated and improved electrochemical properties of Li2MnSiO4 cathodes by hydrothermal reaction for Li-ion batteries

Li2MnSiO4 cathode materials were hydrothermally synthesized from commercial LiOH, Mn(Ac)(2), Si(OC2H5)(4) in aqueous solution. The technic factors, such as temperature, time, compactness and molar ratio of Li:Mn:Si, were systematically studied by orthogonal test method. The optimization hydrothermal synthesis of Li2MnSiO4 is determined as the condition of the reaction temperature at 200 degrees C, the reaction time of 72 h, the compactness of 75 vol% and the molar ratio of Li:Mn:Si as 2:1:1. Among them, the influence of the temperature on the electrochemical performance of the sample is the greatest. An X-ray diffraction pattern confirms the formation of the orthorhombic structure with Pmn2(1) space group. The Li/Li2MnSiO4 cells delivered an initial discharge capacity of 226 mAh/g for as-synthesized following heat-treated Li2MnSiO4 under the optimized conditions. It is surprising to note that heat-treated Li2MnSiO4 exhibits more stable and superior cycling performance than reported values elsewhere, which is due to the unique morphology as well as well crystallization during high temperature sintering. (C) 2012 Elsevier Ltd and Techna Group S.r.l. All rights reserved.