Green sustainable, facile nitrogen self-doped porous carbon derived from chitosan/cellulose nanocrystal biocomposites as a potential anode material for lithium-ion batteries

Green sustainable nitrogen self-doped porous carbon anode material for the use in lithium ion batteries was successfully obtained from chitosan (CS) / cellulose nanocrystal (CNC) biocomposites by facile one step casting-carbonization process. Three main factors–the carbonization temperature, the interfacial compatibility, and the N-doping content—synergistically affected the electrochemical performance of the CS/CNC porous carbon anode. High N-doping content and moderate interfacial compatibility between CS and CNC played a more crucial role in samples' electrochemical performance at the low temperature (800°C) and at the high temperature (1500°C), respectively. The pyrolyzed carbon tended toward stability after the temperature reached 1200°C, corresponding to the more stable cycling performance and higher Coulombic efficiency of the electrodes. Incorporation of CNC effectively promoted the rate retention and cycling stability. The CS/CNC-1200-10 electrode with moderate interfacial bonding, relatively high specific surface area, C/N ratio as well as the reasonable multiscale pore distribution including abundant micropores and a few mesopores and macropores showed a good average specific capacity (333 mAh g−1) at 100 mA g−1, retention capacity (251 mAh g−1) at 2000 mA g−1, as well as an excellent cycling stability (327 mAh g−1) after 50 cycles.