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

摘要

Recently, 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 Fg~(-1) at 1 Ag~(-1). Additionally, the symmetric super-capacitor had a specific capacitance retention rate of 78 at 10 mVs~(-1) and low resistance in the aqueous electrolyte of 1 M H2SO4. The maximum energy density was 19.53 Whkg~(-1) at an optimum power density of 132.32 Wkg~(-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.