Keggin-type aluminum polyoxocation/graphene oxide hybrid as a new nanostructured electrode for a lithium ion battery

Graphene oxide (GO) is one of the fascinating host materials. GO-based materials are quite intriguing from both the perspective of fundamental science and technology, because they are nontoxic, chemically tolerant, and mechanically hard. Such properties suggest wide application of GO-based materials, such as catalyst supports, structural components, and energy storage. In this study, we are quite successful in fabricating a highly ordered nanostructure composed of layered graphene oxide and keggin-type aluminum polyoxocationic species (Al ₁₃). Interlayer spacing in GO increases from 0.64 nm to 1.64 nm, which is due to the intercalation of keggin-type polyoxocation into the layered GO lattice. Remarkable increase in basal spacing could result in an enhancement of discharge capacity in lithium ion batteries (LIBs). Al ₁₃- intercalated GO exhibits much larger reversible capacity, compared to that of the pristine GO, highlighting the effectiveness of pillaring reaction for the electrode in LIBs. Such an enhancement of discharge capacity upon the hybridization is due to the formation of an open framework, leading to the facile and effective access of lithium ions to all of available sites.