Improved Electrochemical Performance of Li[sub 2]MnSiO[sub 4]/C Composite Synthesized by Combustion Technique

cathode powders were synthesized by a simple combustion technique using citric acid as a chelating agent. The as-synthesized powder was ballmilled with acetylene black (0–20 wt %) and heated at in argon atmosphere to form a composite. X-ray powder diffraction indicated the formation of possessing an orthorhombic crystal structure along with manganese oxide as a minor impurity phase. Field-emission-scanning electron microscopy showed that pristine consists of large agglomerates of . The addition of acetylene black resulted in a drastic change in morphology for composites consisting of uniform grains of . The electrochemical discharge capacity as well as the rate capability of also improved dramatically with an increasing amount of conducting carbon (acetylene black) in the matrix, and a value as high as was obtained at a current density of . Impedance spectroscopy showed that the addition of acetylene black decreases the charge-transfer impedance and checks the growth of cell impedance during cycling. Cyclic voltammetry showed two oxidation/reduction couples at 3.6/2.9 and 4.5/4.3 V with good reversibility.