Nitrogen, oxygen and sulfur co-doped hierarchical porous carbon toward high performance supercapacitor by dual activation strategy

Pore structure modulation and heteroatom doping are two very important strategies for designing high performance porous carbon materials. Herein, we prepare nitrogen, oxygen and sulfur co-doped hierarchical porous carbon electrode by a scalable ZnO-KOH dual activation treatment of CMC-LS-urea aerogel (CMC: sodium carboxymethyl cellulose; LS: sodium lignosulfonate). The achieved porous carbon material possesses a high specific surface area (2898.2 m 2  g −1 ), hierarchical porous structure (V meso  = 0.43 cm 3  g −1 , V micro  = 0.93 cm 3  g −1 ) and rich heteroatom contents (O: 17.4 at%; N: 5.96 at% and S: 0.59 at%). The optimal sample demonstrates an exceptional specific capacitance of 342.5 F g −1 at the current density of 0.1 A g −1 and a high capacitance retention rate of 93.7 % after 30000 cycles in 6 M KOH electrolyte. Furthermore, the assembled symmetric capacitors exhibit a high energy density of 33 Wh kg −1 in 1 M TEABF 4 /AN organic electrolyte. This method also can be applied to other natural polymers precursors system for highly efficient and environmentally friendly energy storage.