Optimized mesopore design in ginkgo nuts-derived hyper-crosslinked porous carbon for enhancing supercapacitor capacitance performance

Abstract

The capacitance performance of a co-doped carbon-based supercapacitor derived from Ginkgo nuts was significantly enhanced by optimizing the mesoporous structure through high-temperature pyrolysis combined with KOH activation. The precisely engineered GBHHPC-750-4 is characterized by a hyper-crosslinked 3D hierarchical porous structure, with an exceptionally high specific surface area of 3163.9 m²/g, a substantial mesopore proportion (Vmeso/Vt = 74.1 %), a broad pore size range of 2–10 nm, and elevated levels of heteroatom doping (3.4 at.% N, 8.3 at.% O, 1.6 at.% P). The symmetric supercapacitor based on the GBHHPC-750-4 electrode exhibits a peak specific capacitance of 256 F/g at 1 A/g, achieves an energy density of 118.2 Wh kg⁻¹, maintains an impressive rate capability of 63.6 % across a wide current range (0.5–20 A/g) and demonstrates a prolonged cycle lifespan with 88.0 % capacitance retention after 5000 cycles in 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMIMBF₄) electrolyte, emphasizing the substantial potential of the optimized mesoporous carbon material for energy storage applications.