Porous and graphitic structure optimization of biomass-based carbon materials from 0D to 3D for supercapacitors: A review

Owing to the environmental friendliness, renewability, and biodegradability of biomass, tremendous efforts have been devoted to use them as promising carbon precursors in sustainable energy storage devices. Biomass-based porous graphitic carbon (BPGC), possessing both large specific surface area and good conductivity, has received particular attention as an electrode material in supercapacitors. Herein, this review summarizes the latest progress toward the preparation methods of BPGC, which include activation, catalytic graphitization, and simultaneous activation-graphitization, and special attention is given to the mechanisms of structure evolution during activation and graphitization. The review also presents the advances for optimizing and restructuring the microstructure of BPGC from 0D to 3D. Besides, structure-performance correlation of BPGC for supercapacitor is presented and discussed. Furthermore, insights into challenges and opportunities for the further development of BPGC for energy storage are pointed out. Overall, this review will not only help researchers choose appropriate method to construct BPGC, but also open various directions to optimize ions and electrons transport for high-performance energy storage devices.