CALCULATING CAPACITANCE OF IONIC LIQUIDS: THE INFLUENCE OF ELECTRODE MATERIAL

摘要: Ionic liquids are salts with melting points close to room temperature. Their tuneable combination of properties makes them a favorable alternative to the common organic solvents and can be chosen for cutting-edge fundamental research as well as for specific applications such as electric double layer capacitors, dye sensitive solar cells, and metal-ion batteries [1, 2]. In this work, we focus on the capacitance of the electric double layer (EDL), which we split into two parts: the typical parallel plate capacitance (CMD) and the quantum capacitance (CQ)[3]. We investigated four different systems: BMImI and EMImBF4 at C (0001) and Bi (111) electrode surfaces. We estimated CMD by molecular dynamics (MD) simulations performed using GROMACS 2016.4, and CQ by density functional theory (DFT) calculations using GPAW 1.2. 0 code. From the MD simulations, the potential drop at a given surface charge density was …