 A new positive electrode material MgNiSiO4 was synthesized via a molten salt method using potassium chloride flux. XRD patterns showed that MgNiSiO4 has an orthorhombic system with space group Pbnm(62). It gave the best result with discharge capacity 121.1 mAh g−1 in the fifth cycle at 10 mA g−1 current density. Cyclic voltammetry and galvanostatic cycling disclosed that the kinetic properties have important impacts on the electrochemical performance of this material.