Structural Rigging of Lignin Precursors for Customized Porous and Graphene-Like Carbons towards Enhanced Supercapacitive Performance in Aqueous and Non-Aqueous Electrolytes

Maximum supercapacitive performance in different electrolytes is desirable in the design of advanced carbon materials but still challenged by the conflicting properties of electrolytes. Herein, a practical and scalable strategy to customize carbon materials for aqueous and non-aqueous electrolytes was proposed via structural rigging of lignin precursors. The resultant graphene-like hierarchical porous carbon sheets from low-molecular-weight lignin exhibit a high electrical conductivity of 17.8 S cm(-1), a prominent capacitance of 245 F g(-1) at 1 A g(-1) and impressive chemical stability in the symmetric supercapacitor of ionic liquid electrolyte. The top-level energy density of 96.7 Wh kg(-1) at a power density of 0.9 kW kg(-1) and 48.5 Wh kg(-1) at 20.5 kW kg(-1) is also obtained. In contrast, the 3D oriented N/O co-doped porous carbon composed of high-molecular-weight lignin possesses high specific surface area (>2400 m(2) g(-1)), regulated micropores and rich heteroatoms for remarkable specific capacitances of 402 F g(-1) and 306 F g(-1) at 1.0 A g(-1) in three- and two-electrode configurations of aqueous electrolyte, respectively. The established formation mechanisms further extend the exploration of highly plastic lignin precursors for diverse energy storage systems.