Waste-to-wealth conversion of shrimp shells into B/N/O co-doped hierarchical porous carbon: Experimental realization and theoretical elucidation of energy storage mechanisms

B/N/O co-doped hierarchical porous carbons were derived from waste shrimp shells. • SHPC-800 delivers an impressive specific capacitance of 426.8 F/g at 0.5 A/g. • SC device achieves a remarkable energy density of 19.58 Wh/kg at 750 W/kg. • DFT reveals differential contributions of functional groups to K adsorption capacity. The rational design of carbon derived from biomass for supercapacitors requires a deep understanding of the synergistic interplay between heteroatom doping and pore architecture. Herein, an integrated “pretreatment-co-doping-synchronous activation” strategy was proposed to fabricate B/N/O co-doped hierarchical porous carbon (SHPC) from waste shrimp shells. Leveraging the natural CaCO 3 as a template and exploiting etching effect of KOH and ammonium pentaborate tetrahydrate, the optimized SHPC-800 electrode exhibits a specific surface area of 612 m 2 /g, featuring a well-developed micro-/mesoporous network. The B/N/O co-doping upgrades the capability of the electrode by introducing additional pseudocapacitance and improving electronic conductivity, resulting in an exceptional specific capacitance of 426.8 F/g at 0.5 A/g. Moreover, a symmetric supercapacitor constructed with SHPC-800 demonstrates a remarkable energy density of 19.58 Wh/kg at 750 W/kg, along with extraordinary cycling stability. Additionally, density functional theory (DFT) results further reveal that the contributions of different functional groups to K atom adsorption and electronic regulation vary significantly, and that the performance depends not merely on the type or total amount of dopants but critically on the bonding configuration and coordination environment. These findings provide valuable insights for the structural regulation and performance optimization of porous carbons. This work not only advances the theoretical framework of heteroatom incorporation and pore architecture synergy in biomass-derived carbons but also provides a viable pathway for valorizing seafood waste into high-value electrode materials for next-generation energy storage systems. Download: Download high-res image (446KB) Download: Download full-size image