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

Abstract

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 ZnAc 2 ‐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 H 2 SO 4 and Li 2 SO 4 electrolyte over 10 000 cycles.