Different types of ionic liquids and zwitterionic compounds containing carbonyl-functional groups were prepared and their electrochemical properties were investigated. FT-IR study clearly demonstrates that they are able to interact with Li+ ions through their carbonyl groups, which helps the electrochemical properties enhance. In addition, comparing with the cases of their corresponding alkyl-substituted relatives, their C-rate performance was much better upon their addition to to a non-aqueous electrolyte containing LiPF6, implying the positive role of the ester functional groups.
