In-situ NaCl nanocrystals template-induced self-assembly method to prepare anthracite-based hierarchical porous carbon with network-like structure for high-rate-performance supercapacitors

Using anthracite with high aromatic carbon content as the precursor, we propose an in situ sodium chloride (NaCl) nanocrystals template-induced self-assembly method to prepare high rate performance supercapacitor electrode materials. The capacitive carbon prepared in this method is characterized by hierarchical porous structure, network-like structure, and good electrical conductivity. With the synergistic effect of these structural features, it exhibits excellent supercapacitor performance. The optimum product (CPC-Na-5) displays high capacitance of 373 F g−1 at 0.5 A g−1 and still has 43 % capacity retention at 100 A g−1. The assembled symmetrical supercapacitor shows excellent rate performance with 86 % capacitance retention from 0.5 A g−1 (202 F g−1) to 50 A g−1 in 6 M KOH electrolyte. In the EMIMBF4 electrolyte, the energy density is 56.4 Wh kg−1 at 441.3 W kg−1 and remains 10 Wh kg−1 when the power density is increased to 27,375 W kg−1.