Two members of the family of orthosilicate, Li 2FeSiO 4 and Li 2MnSiO 4, are prepared by a citric acid assisted sol–gel method. As cathode materials for lithium-ion batteries, their structural, morphological and electrochemical characteristics are investigated and compared. Both cathode materials have nanoparticles with similar lattice parameters. Li 2FeSiO 4 has a maximum discharge capacity of 152.8 mAh g −1, and 98.3% of its maximum discharge capacity is retained after fifty cycles. However, the discharge capacity of Li 2MnSiO 4 fades rapidly and stabilized at about 70 mAh g −1 after twenty cycles. The electrochemical impedance and differential capacity analysis indicate that Li 2MnSiO 4 has larger charge transfer impedance and higher electrochemical irreversibility than Li 2FeSiO 4, which makes its electrochemical behaviors seriously deteriorate and leads to difference between two silicate materials.