A systematic investigation of the major impurities content as well as of their effect on the electrochemical behavior of synthesized N-butyl-N-methylpyrrolidinium (Py 1.4 ), N-(2-methoxyethyl)-N-methylpyrrolidinium (Py 1.102 ) and 1butyl-3-methylimidazolium (bmim) bis(trifluoromethanesulfonyl)imide has been carried out and the efficacy of an optimized multistep purification protocol for obtaining ILs suitable for electrochemical applications has been verified.