Characterization of silicate based cathodes for Li Ion Batteries

The silicate compounds Li$_{\mathrm{2}}$MSiO$_{\mathrm{4}}$, where M$=$ Mn, Fe, Co and Ni have gained interest as electrode materials for Lithium ion batteries due to their high theoretical capacity (\textgreater 330mAh/g), high thermal stability due to strong Si-O covalent bonds, environmental friendliness, and low cost. However, these materials intrinsically have low electrical conductivity. To improve conductivity of these classes of electrode materials, we synthesized Li$_{\mathrm{2}}$MnSiO$_{\mathrm{4}}$ and Li$_{\mathrm{2}}$FeSiO$_{\mathrm{4}}$ by solid state reaction in an argon atmosphere. The lithium transition metal silicates were compounded with graphene nano-sheets and the composites were used as positive electrode in a coin cell configuration. . The materials structure-composition, morphology, conductivity and electrochemical performance were characterized by XRD, XPS, SEM, TEM and electrochemical techniques.The detail structure-composition analysis and electrochemical performance of the silicate electrodes will be reported.