Electrochemical Performance of Symmetric Supercapacitor Based on Activated Carbon Biomass TiO2 Nanocomposites

Abstract

A supercapacitor (SC) is an energy storage device with high energy density, high power density, long life cycle and a bundant material in nature.. Activated carbon based on coconut shell waste (ACCS) is one of the most promising supercapacitor base materials due to its abundance in nature, environmentally friendly, and high surface area. Activated carbon based on coconut shell (ACCS) waste is a potential material as a supercapacitor base material. This is because ACCS has undergone chemical and physical activation, has a high surface area, is abundant in nature, and is environmentally friendly. However, ACCS has common ionic transport diffusion, resulting in inefficient utilization of activated carbon surface area. Therefore, ACCS composite with TiO2 material is needed. TiO2 material with a small particle size can be used to reduce the aggregation so it can increase the electrolyte to an active redox site. Therefore, this research was conducted to obtain information about the most optimum activation method for ACCS biomass and the supercapacitors enhancement with ACCS-TiO2 composite to obtain great ionic diffusion performance and an effective surface area utilization. In brief, the experiment was started by preparing the composite solutions with various compositions of TiO2 (0%, 10%, 15%, and 20%). The deposition was carried out using the doctor blade technique on the aluminum foil based substrate and the liquid electrolyte of 1 M Et4NBF4 was injected between the electrodes. The crystal structure, morphology, and elemental analysis of the composite were identified using X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM), and Energy Dispersive X-ray (EDX), respectively. Charge Discharge was applied to measure the electrical performance of the device. The highest performance of symmetric supercapacitor was performed by TiO2 15% that able to show its cyclic reversibility at the voltage range of 0-2 V, generated a specific capacitance of 53.10 F g-1 with the power density and maximum energy density of 367.05 W kg-1 and 26.15 Wh kg-1, respectively. Over 50 cycles, its maximum energy density was decreased to 24.83 Wh kg-1 with the capacity retention of 94.64 %.