Synthesis of porous Si/graphite/carbon nanotubes@C composites as a practical high-capacity anode for lithium-ion batteries

Abstract There are still several challenges to synthesize a practical, high capacity and stable Si-based anode materials. Here we report a porous Si-based composites, which consists of nano silicon (obtaining high capacity), graphite (gaining stable structure), carbon nanotube (increasing electron conductivity), and pitch (porous structure as well as a binder), by spray-drying method. We then optimize the content of pitch in the composites. The composite with 11.5 wt% carbonized pitch delivers excellent electrochemical performance. It shows an initial reversible capacity of 863.2 mAh g−1 at 100 mA g−1, and exhibits capacity retention of 81.3% after 100 cycles. The composite also possesses good rate capability, and up to 89.3% of the reversible capacity can be recovered at 1 A g−1.