Suitable Micro/Mesoporous Carbon Derived from Galangal Leaves (Alpinia galanga L.) Biomass for Enhancing Symmetric Electrochemical Double‐layer Capacitor Performances

Abstract

AbstractRecently, micro/mesoporous biomass‐based functional carbon as an excellent electrode material and energy storage device has attracted massive attention due to the availability of abundant raw materials, adaptability to pore structure, good chemical‐physical behaviors, high conductivity, enhanced energy density, and long life cyclic stability. This study performs micro/meso carbon from the novel galangal leaves biomass through KOH and CO2 activation as electrodes material for symmetric supercapacitors. The activated carbon obtained showed a clear hierarchical pore structure with an excellent micro:meso ratio of 56.72 %:43.28 % which caused their high electrochemical properties. The carbon was further assembled into electrodes through a binder‐free solid disc designed to assess the electrochemical performance as a supercapacitor. The results indicated that the galangal leaves‐based adapted micro/mesoporous carbon obtained a high specific capacitance of 161 F g−1 at 1 A g−1. Additionally, the symmetric supercapacitor had a specific capacitance retention rate of 78 % at 10 mV s−1 and low resistance in the aqueous electrolyte of 1 M H2SO4. The maximum energy density was 19.53 Wh kg−1 at an optimum power density of 132.32 W kg−1. Therefore, the appropriate micro/mesopores carbon ratio based on the novel galangal leaves biomass can be considered as a good electrode material for high‐performance supercapacitor.