Boron and Nitrogen Co-Doped Trimodal-Porous Wood-Derived Carbon for Boosting Capacitive Performance

Heteroatom doping and a porous structure are two significant factors that improve the capacitance performance of carbon-based electrodes, but there are often one-sided considerations between them. Herein, effective B, N co-doping and trimodal-porous structure from the carbonization of sustainable natural wood are obtained at the same time. The unique pore structure is coarsely tuned by a modified ZnAc2-assisted hypersaline route and further fine-tuned by controlling the doping levels of boron and nitrogen. The high specific surface area of porous carbon up to 1201 m(2) g(-1) is coordinated with the trimodal foam-like nanopores. This carbon-based material as a supercapacitor electrode can provide not only trimodal-porous ion transfer highways but also doping-induced pseudocapacitance. The resulting pore and heteroatom reengineered wood-derived carbon harvests a remarkable capacitance of 479 F g(-1) at 1 A g(-1), among the highest values in reported B, N co-doped carbon electrodes. The aqueous symmetric supercapacitor exhibits energy density of 18.5 Wh kg(-1) and power density of 6.4 kW kg(-1), along with >90% capacitance retention, both in H2SO4 and Li2SO4 electrolyte over 10 000 cycles.