Secondary utilization of jujube shell bio-waste into biomass carbon for supercapacitor electrode materials study

Abstract

Currently, the final destination of waste jujube shells from the deep processing of jujubes is usually burnt or simply thrown away, which has a significant impact on the natural environment. In this work, we established a strategy for the secondary use of waste jujube shells to solve the problems above. The jujube shell biomass carbon materials were prepared by using waste jujube shell residue after extraction of essential oils as carbon source, ZnCl2 as activator, boric acid and urea as dopants. In the three-electrode system, the specific capacitance of the boron-nitrogen co-doped carbon supercapacitor is 535F/g at the current density of 1 A/g, and the capacitance retention rate is 62.8%, Moreover, the assembled symmetrical two-electrode supercapacitor in an aqueous KOH electrolyte presented considerable synergetic energy–power output properties with an energy density of 13.97 Wh/kg at a power density of 250.0 W/kg, and 5.58 Wh/kg at 2.5 kW/kg.

Keywords

• Biomass carbon
• Double heteroatom doping
• Supercapacitor
• Bio-waste recovery