Applied Surface Science, Vol.467, 382-390, 2019
Facile and green synthesis of 3D honeycomb-like N/S-codoped hierarchically porous carbon materials from bio-protic salt for flexible, temperature-resistant supercapacitors
3D honeycomb-like N/S-codoped hierarchically porous carbon materials were prepared from chitosan-protic salt ([Chit][HSO4]) by a combined method of double soft-template and solvent-free self-assembly. The key to this preparation strategy: no any solvents or catalysts are used; F127 and sodium dodecyl sulfate are respectively used as mesoporous and macroporous soft templates, as well as [Chit] [HSO4] not only can be used as a carbon source, N/S source, but also as a microporous porogen during carbonization. The features of unique honeycomb-like hierarchical pore structure, large specific surface area of 927 m(2)g(-1) and high heteroatom doping (N: 5.13 at %, S: 2.51 at %) simultaneously exist, significantly improving the electrochemical performance of as-obtained carbon materials. A high capacitance of 302 Fg(-1) and an excellent cycling stability with 99% capacity retention over 5000 cycles have been obtained in KOH electrolyte. Notably, the assembled symmetric flexible solid-state supercapacitors still maintain excellent capacitance property and stability under the extreme temperatures (- 20 degrees C similar to 100 degrees C) and bending (0 degrees similar to 180 degrees). Furthermore, in Na2SO4 electrolyte, the supercapacitors display an outstanding energy density of 17.6 Wh kg(-1) at a power density of 250 W kg(-1). The fascinating performance significantly endows 3D honeycomb-like N/S-codoped hierarchically porous carbon materials with great potential for high-efficient energy storage.