Self‐template synthesis of hierarchical porous carbon for supercapacitors based on bituminous coal

다국어 초록 (Multilingual Abstract)

We develop a unique self‐template method to synthesize hierarchical porous carbons (HPCs) by co‐activation of heavy component (HC) and dense medium component (DMC) separated from bituminous coal. HC and DMC are obtained by employing the mixture solvent (CS2/N‐methyl‐2‐pyrrolidone) and deionized water as extractant and back extractant to separate bituminous coal. The plentiful kaolinite [Al2(Si2O5) (OH)4] in the HC produce Natrolite (K) (K2Al2Si3O10•2H2O) during the activation process, which can serve as self‐template to prepare HPCs. Moreover, the addition of asphalt‐like DMC allows the templates to be better utilized. Effect of the remixture ratio of DMC/HC on HPCs' porous structures and electrochemical properties are studied in detail. The optimal sample (HPC‐0.4) displays an ultrahigh surface area (3851 m2 g−1), appropriate hierarchically system and excellent conductivity. When applied to supercapacitors, HPC‐0.4 delivers a large capacity of 436 F g−1 at 0.1 A g−1 in alkaline electrolyte, and maintains 212 F g−1 at 10 A g−1. This self‐template strategy paves a practical route to construct applicable porous carbons for supercapacitors from low‐cost high‐minerals coal.
A unique self‐template strategy was presented to construct hierarchical porous carbon based on separation and remixture of bituminous coal. The as‐obtained carbon delivers an ultrahigh specific area (3851 m2 g−1) and appropriate hierarchically system. The assembled supercapacitors exhibited high capacitance (436 F g−1 at 0.1 A g−1), good rate performance (212 F g−1 at 10 A g−1) and cycling stability (92.7% retention after 6000 cycles).