Comparison of pretreatment methods for producing active carbon from coffee industry waste with potato hydroxide activators for lithium ion capacitor applications

Abstract

Research on the synthesis of activated carbon from coffee industrial waste has been successfully carried out using the pretreatment method. Samples are carried out by varying the calcination temperature (600 °C; 700 °C; 800 °C). Samples were tested for iodine to determine the surface area of activated carbon, characterized by Optical Microscopy (OM), conductivity behavior was studied by Electrochemical Impedance Spectroscopy (EIS) and Cyclic Voltammetry (CV) testing to determine electrochemical performance. Iodine test results produce the highest surface area of 2614 m2/gr. Based on the morphological results using OM, the surface morphology looks relatively homogeneous. A lithium-ion capacitor cell with sample C1 as a carbon cathode synthesized by the steam hydrothermal method has the smallest semicircle with the highest conductivity of 14 × 10−5 S/cm and a specific capacitance of 31.25 F/g which indicates better electrochemical performance than other cells.