Coal-based 3D hierarchical porous carbon aerogels for high performance and super-long life supercapacitors

Coal-based 3D hierarchical porous carbon aerogels (3D HPCAs) has been successfully fabricated from a freeze-drying method and with subsequent of calcination process, using coal oxide as carbon precursors, and PVA as both cross-linking agent and sacrifice template. The 3D HPCAs, using as electrode materials for supercapacitors, display outstanding electrochemical performance. The optimal sample (HPCAs-0.4-800) presents a high specific capacitance of 260 F g^-1 at 1 A g^-1, and exhibits considerable rate capability with the retention of 81% at 10 A g^-1. Notably, HPCAs-0.4-800 shows an excellent cycling stability with 105% of the capacitance retention after 50000 cycles at 10 A g^-1, attributing to its unique hierarchical porosity, high surface area up to 1303 m² g^-1, and improved conductivity. This work offers a promising route to synthesize coal-based porous carbon aerogels electrode materials for supercapacitors.