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Influence exerted by the temperature of annealing in the atmosphere of argon on the ability of Si‒C nanocomposites to enable a reversible introduction of lithium has been studied. It was found that the higher the annealing temperature in the formation of a composite, the lower the capacity of the electrode fabricated from this composite. X-ray diffraction analysis and scanning electron microscopy demonstrated that the capacity decreases because silicon carbide of cubic modification β-SiC inactive toward formation of lithium alloys or intercalates is formed at T ≥ 1100°C. [ABSTRACT FROM AUTHOR]

A novel method to fabricate porous silicon–carbon nanocomposites has been suggested. The method uses carbon monofluoride reduction by silicon. The produced composite materials are formed by silicon nanoparticles confined into a carbon shell. The contacts of these particles provide current flowing across the formed carbon matrix. The dependences of density, porosity, and resistivity on the composition of Si–C composite pellets obtained by the suggested method have been determined. The studied materials are of interest for developing negative electrodes for lithium-ion batteries with high capacity. [ABSTRACT FROM AUTHOR]