Assessment of the electrochemical behaviour of silicon@carbon nanocomposite anode for lithium-ion batteries

Silicon nanocomposites have great potential applications in lithium-ion batteries. However, huge mechanical strain, capacity retention and unstable solid electrolyte interface formation weaken their applications in the real world. To overcome the above challenges, a novel facile route was adopted to design nanostructured silicon core carbon shell composites (Si@C), where the carbonization of phenolic resins led to a uniform porous thin interfacial layer of carbon. The phenolic resin precursor endowed mesoporous morphology with the carbon layer due to the carbonization of aromatic carbon, methylene linkages and hydroxyl groups. The mesoporous conductive carbon helped effectively to control the mechanical strain of silicon nanoparticles which maintained the integrity of Si@C nanocomposites and provided effective channels to easy access of electrolyte and short lithium ions transport. This novel Si@C anode offered a stable specific capacity of ∼868 mAh g⁻¹ at 0.1 Ag^-1 up to 500 cycles with ≥99% columbic efficiency.