Molecular Dynamics Simulation Study Of NaCl Aqueous Electrolyte In Carbon Nanopores

Energy-related sustainable development and environmental protection are among the most crucial topics that are encountered worldwide. Energy storage device plays a key role in the related area. As a new energy storage device, supercapacitor, also called electrical double-layer capacitor, fits the gap between the battery and conventional capacitor. It is featured by high power density, large energy storage and long cycling lifetime. Its applications can be found in national defense industries, aeronautical industries, transportation sector and others, it is also the focus of new energy research field.This work studies the hydrated ion system in the nanopores of supercapacitor in help of molecular dynamics simulation based on GROMACS software. The modeling takes NaCl-water solution as electrolyte meanwhile activated carbon is chosen as electrode material. Fundamental properties of hydrated ions in nanopores are calculated and analyzed by means of adjusting concentration and surface charge density. The radial distribution function and coordination number of hydrated ion are studied, and the desolvation energy of ions in nanopores and bulk zone are discussed. Moreover, relative density of ions and solvent molecules in carbon nanopores are analyzed, it is found that relative density of solvent molecule is decreased in cathode but is increased in anode.In the molecular dynamics simulation of NaCl aqueous electrolyte in nanopores, coordination number as well as solvated radius and desolvation energy is measured. Concentration is found to little impact ionic coordination structures and desolvation energy, but desolvation energy of ions in carbon nanopores is greater than that in bulk zone. By means of analyzing relative density of ion in nanopores, Na+ is found to accumulate in cathode whereas Cl- is found to accumulate in anode; therefore the distribution scenario of ions in carbon nanopores is obtained.