1-Aza-15-Crown-5 Functionalized Graphene Oxide for 2D Graphene-Based Li+-ion Conductor

Attachment of Li+ ion on graphene surface to realize Li+-ion conductor is a real challenge because of the weak interaction between the ions and the functional groups of graphene oxide; although, a large number of theoretical results are already available in the literature. To overcome this problem, graphene oxide is functionalized by 1-aza-15-crown-5, the cage-like structure containing four oxygens that can bind Li+ ion through electrostatic interaction. Li+ migration on graphene surface has been investigated using ac relaxation mechanism. Perfect Debye-type relaxation behavior with beta (relaxation exponent) value approximate to 1 resulting from single ion is observed. The activation energy of Li+ migration arising due to cation-pi interaction is found to be 0.37 eV, which agrees well with recently reported theoretical value. It is believed that this study will help to design isolated ion conductors for Li+-ion battery.