N-doped rGO/C@Si composites using sustainable chitosan as the carbon source for lithium-ion batteries

The research is aimed at a way to solve the problem of silicon (Si) reciprocating volume change and poor electrical conductivity during charge/discharge. Here, we prepared high-performance N-doped rGO/C@Si anode material with renewable chitosan as both N source and C source and GO as the additive by a simple one-step pyrolysis method without adding reducing agent. Because of containing the biomass amorphous carbon layer and rGO, the bifunctional conducive layer not only alleviates the stress maintaining electrode integrity during lithiation/delithiation, but also compensates for the poor conductivity of Si. N doping can effectively improve the wettability of electrolyte and electrode interface. In addition, the affinity to lithium of amorphous carbon also increases greatly. Therefore, the designed N-doped rGO/C@Si anode material shows superior cycling performance (1115.8 mAh g(-1) after 150 cycles at 420 mA g(-1)) and better rate capability (1077.4 mAh g(-1) at 4200 mA g(-1)).