High performance supercapacitor electrodes based on B/N Co-doped biomass porous carbon materials by KOH activation and hydrothermal treatment

The N and B co-doped hierarchical porous carbon with excellent textured properties by using two-step of activation and hydrothermal post-treatment process using ammonium pentaborate tetrahydrate (NH4B5O8 center dot 4H(2)O) as both nitrogen and boron source are developed. The results showed that BNAC-3 has the maximum surface area (2471 m(2)/g) caused by the highest degree of micro/mesopores (0.82 and 0.35 cm(3)/g) and the linked 3D network are advantageous for the circulation of electrolytes and electrostatic adsorption. The contribution of Faradaic pseudocapacitance may be caused by high B (3.12 wt percent) and N (2.02 wt percent) contents of BNAC-3. Additionally, BNAC-3 exhibits excellent electrochemical efficiency with an ultra-high specific ability of 369 F/g at 1 A/g current density (CD) and maintains 240 F/g at 20 A/g in three-electrode systems. Notably, in a two-electrode device, maximum energy density can be almost 12.0 W h/kg at a power density (PD) of 375 W/kg. (C) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

The N and B co-doped hierarchical porous carbon material prepared through a two-step activation and hydrothermal post-treatment process exhibits high specific surface area, facilitating electrolyte circulation and electrostatic adsorption. The high boron and nitrogen content contributes to Faradaic pseudocapacitance, leading to excellent electrochemical performance at high current densities.