Molecular Dynamics Study of Electrolyte Effects on Carbon Electrode in Supercapacitors

Abstract

The demand for efficient and sustainable global energy sources continues to increase alongside technological developments. In this case, the development of electrical energy storage devices, such as supercapcitor, is essential. Supercapacitors have a fairly high capacitance, large power density, fast charging and discharging processes, and good durability. Computational studies through molecular dynamics simulations were conducted to understand the properties and dynamics of a supercapacitor system with activated carbon-based electrodes. This study aims to observe the effect of electrolyte types on the properties of activated carbon as a supercapacitor electrode based on the dynamic movement of electrolyte ions in the system molecular dynamics simulations using Large Scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) software with OPLS-AA force field parameters were carried out to study the supercapacitor system. The variations of electrolyte systems studied include C₃H₅N₂⁺/BF₄⁻, C₃H₅N₂⁺/CH₃COO⁻, and K+/OH- in acetonitrile (ACN) solvent. Simulation results show that the system with C₃H₅N₂⁺/BF₄⁻ electrolyte has the best performance as a supercapacitor system. This is seen from the interface interaction with the electrode and good ion diffusion, the highest ion diffusion coefficient value of 18,4×10^-11 m²/s, and the highest specific capacitance value of 199,86 μF/cm².