Long-Life Aqueous Zinc-Ion Batteries of Organic Iminodianthraquinone/rGO Cathode Assisted by Zn2+ Binding with Adjacent Molecules.

Organic compounds have been extensively used as zinc-ion battery (ZIB) cathodes due to their high capacities and outstanding properties. Nevertheless, poor electrical conductivity limits their developments. RGO (reduced graphene oxide) can well interact with organic compounds through π-π stacking for furnishing capacious ion diffusion paths and active sites to enhance conductivity and capacity. Herein, a 1,1'-iminodianthraquinone (IDAQ)/rGO composite is utilized as cathode of ZIBs, demonstrating ultrahigh stability with 96% capacity retention after 5000 cycles. Zn2+ and H+ synergetic mechanism in IDAQ/rGO has been deeply discussed by ex situ analysis and theoretical calculation. Consequently, the structure of IDAQ2(H+)6(Zn2+) is the most probable product after discharging progress. Prospectively, the IDAQ/rGO material with excellent stability and good performance would provide new insights into designing advanced ZIBs.