Hydrothermal synthesis and properties of manganese-doped LiFePO4

• DOI: 10.1007/s11581-012-0700-5
• Publication Date: 2012-04-02T22:29:47Z
• Authors: Rui-Rui Zhao; Bing-Yan Lan; Hong-Yu Chen; Guo-Zheng Ma
• Keywords: Carbon fibers; Hydrothermal Synthesis

A series of carbon-coated LiFe1 − xMnxPO4 compounds are prepared by a hydrothermal method at 170 °C for 12 h. The structure and morphology of the prepared composites are characterized to examine the effects of Mn2+ substitution. All LiFe1 − xMnxPO4 compositions are found to have an ordered olivine-type structure with homogeneous Fe2+ and Mn2+ distributions. The substitution leads to grain refinement from ~500 to ~150 nm, as well as to increased initial capacity and improved electronic conductivity. The amount of carbon coating varies with increased doping amount. The discharge curves of the LiFe1 − xMnxPO4/C materials reveal a high discharge plateau corresponding to Fe2+/3+ and no obvious plateau assigned to Mn2+/3+, although a slight contribution of manganese is detected. However, the electrochemical performance, including the discharge capacity and cyclic performance, deteriorates with increased Mn content in the composite.