Porous carbon can significantly improve the energy storage performance of supercapacitors through fast ion transport and charge transfer kinetics. Therein, the fabrication of hierarchical porous carbon nanosheets by means of a sustainable and cost-eff...
Porous carbon can significantly improve the energy storage performance of supercapacitors through fast ion transport and charge transfer kinetics. Therein, the fabrication of hierarchical porous carbon nanosheets by means of a sustainable and cost-efficient synthetic strategy has attracted considerable interest. Herein, 2D lignin-based carbon nanosheets (N-LHPC) with hierarchical pore structures were facilely synthesized by a one-pot process of nitrogen and oxygen co-doping method. The nitrogen doping and in-situ MgO template embedded in the carbon matrix were successfully achieved by combining the sustainable resource lignin with melamine and metal chlorides. The optimized N-LHPC exhibits a unique 2D lamellar morphology with layered pores, and due to the advantages of its abundant pore structure, N-LHPC exhibits a high specific capacitance of 235.75 F/g at 0.5 A/g and excellent rate capability performance in alkaline electrolytes. In addition, the symmetrical supercapacitor based on N-LHPC achieves a maximum energy density of 14.75 Wh/kg at the power density of 450 W/kg, demonstrating good application prospects. The synthetic N/O co-doping strategy proposed in this work provides lignin-based carbon materials with hierarchical nanostructure, abundant pseudocapacitive active species, and good electron/ion transfer properties, which are responsible for the excellent capacitive properties of the optimized materials.