Rational synthesis of chitin-derived nitrogen-doped porous carbon nanofibers for efficient polysulfide confinement

Principles of inexpensive biotechnology are being increasingly used to address the problems posed by the use of lithium-sulfur batteries.We used chitin,a low-cost marine biowaste product,as a precursor for the in-situ preparation of chitin-derived nitrogendoped hierarchical porous carbon fibers(CNHPCFs)containing abundant pores.These materials are characterized by varying morphologies and high specific surface areas and present a hierarchical porous structure.CNHPCFs adsorb polysulfides,exhibit good ionic conductivity,and can be potentially used to generate green energy.These properties help address the problems of volume expansion and slow transport.The CNHPCF-1@S cathode exhibits excellent cycling performance and high capacity(1368.80 mAh·g^(−1)at 0.2 C;decay rate:0.011%per turn at 5 C).The high electrochemical reversibility recorded for CNHPCF-1@S and the stepwise reaction mechanism followed were studied using the in-situ X-ray diffraction and in-situ Raman spectroscopy techniques.The results reported herein can potentially help develop new ideas for the recycling and treatment of marine biofertilizers.The results can also provide a platform to improve the application prospects of lithium-sulfur batteries.