In situ synthesis of expanded graphite embedded with amorphous carbon-coated aluminum particles as anode materials for lithium-ion batteries

Expanded graphite embedded with amorphous carbon-coated aluminum particle (C@Al-EG) composites were in situ synthesized by chemical vapour deposition (CVD) and ball-milling methods using EG and metallic aluminum as raw materials. Using the characterization and analysis of scanning electron microscopy, X-ray diffraction, alternating current impedance and first charge-discharge curves, the different Al contents in C@Al-EG composites were studied, and the experimental results show that the best performing content for Al was 30 wt%. The C@Al-EG composites exhibited high capacity, excellent cycle stability and rate performance as anode materials for lithium-ion batteries. At a current density of 100 mA h/g, the first reversible capacity of C@Al-EG composites was 401 mA h/g, and the decreasing speed of capacity was slow, with the specific capacity remaining at 381 mA h/g after 50 cycles. The retention rate was up to 95%.