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 pi-pi 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.