The effect of thermal treatment on properties of composite silicon–carbon anodes for lithium-ion batteries

The effect of annealing temperature in argon atmosphere on the ability of Si–C nanocomposites to reversibly insert lithium was investigated. It was found that the higher the annealing temperature during the formation of the composite, the lower is the capacitance of the electrode made from it. X-ray diffraction analysis and transmission electron microscopy reveal that the reason of the capacitance decrease is formation at $T\ge$ 1100$^\circ$C of silicon carbide of cubic modification $\beta$-SiC, inactive with respect to the formation of lithium alloys or intercalates.