Electrochemical characteristics of nc-Si/SiC composite for anode electrode of lithium ion batteries

• Our work has focused on irreversible discharge capacity and capacity retention of nc-Si/SiC composite particles.
• Particles comprised a mixed construction of nc-Si/SiC structure with dual phases.
• The SiC phase acted as retarding media, leading to enhanced cycle stability.

nc-Si/SiC composite particles were prepared as an anode material for lithium ion batteries using a plasma jet with DC arc discharge. The composition of the nc-Si/SiC composite particles was controlled by setting the mole ratio of CH4 and SiH4 precursor gases. X-ray diffraction, TEM images, and Raman shift analyses revealed that the synthesized nc-Si/SiC composite particles comprised a construction of nano-nocaled structure with crystalline phases of active silicon, highly disordered amorphous carbon of graphite and crystalline phases of β-SiC. In the experimental range examined, the nc-Si/SiC composite particles showed good coulombic efficiency in comparison with particles high Si–Si bonding content due to the interplay of particles with a small proportion of carbon and the buffering effect against volume expansion by structural stabilization, and played a role as retarding media for the rapid electrochemical reactions of the SiC crystal against lithium.

Cycling performances and coulombic efficiencies of the nc-Si/SiC composite anodes at different CH4/SiH4 mole ratios.Figure optionsDownload as PowerPoint slide