Porous carbon derived from a by-product of traditional Chinese medicine for high-performance aqueous zinc-ion hybrid supercapacitors

The rational utilization of biomass waste for the production of usable energy holds immense significance. The present study proposes the effective utilization of a byproduct derived from traditional Chinese medicine, specifically momordica grosvenori shell, as a precursor for fabricating high-performance porous carbon electrodes in rechargeable aqueous zinc ion supercapacitors. The MGCx-T electrodes are prepared by KOH activation and carbonization with MG (momordica grosvenori shell). The influence of KOH addition amount and carbonization temperature on the properties of the prepared materials were studied. Resulting that MGC3–800 has good electrical conductivity, high specific surface area (1141 m2 g−1) and abundant pore structure. The maximum specific capacity reaches 228.7 mAh g−1 at 0.2 A g−1 in 2 M ZnSO4 electrolyte. In the gelatin/ZnSO4 electrolyte, the specific capacity reaches a maximum of 186.1 mAh g−1. Additionally, it exhibits an energy density of 167.5 Wh kg−1 and a power density of 6300 W kg−1. Furthermore, exceptional cycling stability is observed with a capacity retention rate of 92.6 % after 10,000 cycles. Hence, the realization of an industry-effective strategy that not only utilizes biomass waste, but also produces high-performance zinc-ion hybrid supercapacitor electrodes has been achieved.