High Electrochemical Performance of Crumpled Paper Ball-like Si-CNT-GR Composites for Lithium Ion Battery Anode Materials

Silicon (Si) particles is considered as promising anode materials in LIB because Si exhibits the highest theoretical energy density of 3579 mAh/g. However, the large volume expansion of Si during lithiation/delithiation process leads to structural degradation and pulverization of the electrode, which leads to solid electrolyte interphase (SEI) film reformation. Graphene (GR) can act as an electrolyte-blocking layer to control the SEI formation on the surface of Si. In addition, Carbon nanotube (CNT) can cushion the volume changes of Si during the cycling and increase electrical conductivity between Si-Si particles. Here, we fabricate crumpled paper ball-like Si-CNT-GR composites by one-step aerosol process. The Si-CNT agglomerates were located inside the GR-wrapped composite ball. The Si-CNT-GR composites exhibited very high performance as LIB anodes. The charge capacity (lithium ions extraction) of Si-CNT-GR electrodes was 1700 mAh/g for Si-CNT-GR composite with 0.05 wt% of CNT. The cycle-ability of Si-CNT-GR composites show a significant improvement compared with commercial Si nanoparticles, retaining over 1400 mAh/g after 50 cycles.