Hierarchical mesoporous Li2Mn0.5Fe0.5SiO4 consisted of nanoparticles or nanoplates has been successfully synthesized for the first time by a hydrothermal method. Their carbon-coated composites are obtained by a heat treatment in the presence of citric acid. These composites were characterized by powder X-ray diffractometry, scanning and transmission electron microscopy, Raman spectroscopy, and thermogravimetric analysis. The lithium storage capacity and cycling performance of the optimized Li2Mn0.5Fe0.5SiO4/C composite are greatly enhanced when tested as a cathode material in lithium-ion batteries (LIBs). It exhibits a discharge capacity of 125mAhg−1after 60 cycles at a rate of 0.1C. This superior electrochemical property could be ascribed to high purity and mesoporous structure of Li2Mn0.5Fe0.5SiO4, which greatly enhances the electronic conductivity as well as the diffusion coefficient of lithium ions.