Dinh Quan Nguyen, Energy & Environment Research Division, Korea Institute of Science and Technology - KIST, 136-791 Seoul, Seongbuk-gu, Hawolgok-dong, 39-1, Seoul, South Korea, Hyun Woo Bae, Kyung Hee University, 1 Hoegidong, Dongdaemoongu, Seoul 130-701, South Korea, Hoon Sik Kim, Dept. of Chemistry, Kyung Hee University, 1 Hoegidong, Dongdaemoongu, Seoul 130-701, South Korea, Hyunjoo Lee, Energy & Environment Research Division, Korea Institute of Science & Technology, 39-1, Hawolgok-dong, Seongbuk-gu, Seoul, South Korea, and Honggon Kim, Energy & Process Research Division, Korea Institute of Science and Technology, Seoul, South Korea.
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.