Effect of Mn substitution on the structural, morphological and electrochemical behaviors of Li2Fe1−xMnxSiO4 synthesized via citric acid assisted sol–gel method

Li2(Fe1−xMnx)SiO4 (x = 0, 0.3, 0.5, 0.7, 1) cathode materials have been synthesized via citric acid assisted sol–gel method. The effects of Mn substitution on the structural, morphological and electrochemical behaviors of Li2(Fe1−xMnx)SiO4 are investigated. The prepared Li2(Fe1−xMnx)SiO4 samples can all be indexed on the basis of the orthorhombic unit cell in space group Pmn21, and their lattice parameters are similar. Nanoparticles can be observed in the samples. The discharge capacity first increases and then decreases with increasing x. The maximum discharge capacity is obtained when x is equal to 0.5. However, the cycling performance of the Li2(Fe1−xMnx)SiO4 samples decreases with increasing x. At the same time, Mn substitution lowers the electrochemical reversibility of the Li2(Fe1−xMnx)SiO4 samples.