Acetonitrile concentration dependent ion mobility and electrochemical behavior of an ionic liquid in MXene

Ionic liquids are promising electrolytes for energy-storing devices. Even though they have high potential windows, they suffer from low conductivity because of high viscosity and are more often mixed with organic solvents. Here, we have explored the electrochemical performances and the ion dynamics of an ionic liquid, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [EmimTFSI], in the presence of acetonitrile employing electrochemical and neutron scattering measurements. A higher capacitance observed at an optimum concentration, associated with increased microscopic dynamics of cations, will be discussed.