Electrochemical double layer capacitors (EDLCs) are a category of supercapacitors; devices that store charge at the interface between electrodes and an electrolyte. Currently available commercial devices have a limited operating potential that restricts their energy and power densities. Ionic liquids (ILs) are a promising alternative electrolyte as they generally exhibit greater electrochemical stabilities and lower volatility. This work investigates the electrochemical performance of EDLCs using ILs that combine the @entity68504 anion with @entity65269 and @entity3104 based cations. Different activated @entity505 materials were employed to also investigate the influence of varying pore size on electrochemical performance. Electrochemical impedance spectroscopy (EIS) and constant current cycling at different rates were used to assess resistance and specific capacitance. In general, greater specific capacitances and lower resistances were found with the @entity65269 based ILs studied, and this was attributed to their smaller cation volume. Comparing electrochemical stabilities indicated that significantly higher operating potentials are possible with the @entity3104 based ILs. The marginally smaller @entity65269 cation performed better with the @entity505 exhibiting the largest pore width, whereas peak performance of the larger @entity65269 cation was associated with a narrower pore size. Considerable differences between the performance of the @entity3104 based ILs were observed and attributed to differences not only in cation size but also due to the inclusion of a methoxyethyl group. The improved performance of the @entity4543 bond containing IL was ascribed to electron donation from the @entity26 atom influencing the charge density of the cation and facilitating cation-cation interactions.

Ionic liquid based EDLCs: influence of XXXX porosity on electrochemical performance.

@entity68504 :: ('MESH:C575299', 'Chemical') :: ['bis(trifluoromethanesulfonyl)imide'] @entity65269 :: ('CHEBI:30488', 'Chemical') :: ['sulfonium'] @entity26 :: ('MESH:D010100', 'Chemical') :: ['oxygen'] @entity505 :: ('MESH:D002244', 'Chemical') :: ['carbon'] @entity4543 :: ('MESH:D004986', 'Chemical') :: ['ether'] @entity3104 :: ('MESH:D000644', 'Chemical') :: ['ammonium']
@entity505 :: (MESH:D002244,Chemical) :: ['carbon']
