High-yield nitrogen-rich carbon electrode materials derived from Lentinula edodes for high-performance supercapacitors

Biomass-derived carbon is frequently used as a highly efficient material for supercapacitors. However, the low yield of biomass-derived carbon during pyrolysis limits its application range. In this study, a simple crosslinking strategy was employed to synthesize nitrogen-doped high-yield Lentinula edodes-derived carbon using urea–formaldehyde (UF) resin. The good compatibility of cellulose chains within Lentinula edodes and polymer chains within UF facilitated the formation of a stable structure during crosslinking. A high carbon yield of 36.09 % was achieved, which exceeded those of the individual components (9.58 % for Lentinula edodes and 22.09 % for UF resin) at the same conditions. Thus, benefited by the doping of N element originated from UF resin, the produced carbon material exhibited high electrochemical performance: its specific capacitance reached 375 F g⁻¹ at 0.5 A g⁻¹ (237.0 F g⁻¹ for Lentinula edodes carbon and 84.2 F g⁻¹ for UF resin carbon) with a 94.1 % capacitance retention after 10,000 cycles conducted at 5 A g⁻¹ (91.9 % for Lentinula edodes carbon and 92.0 % for UF resin carbon). Furthermore, the assembled symmetric supercapacitor demonstrated an energy density of 59.7 Wh kg⁻¹ at 900 W kg⁻¹, and the capacitance retention of 102.3 % after 10,000 cycles conducted at 5 A g⁻¹, indicating a high application potential in the field of energy storage.