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Constructing graphene-based heterostructures with large interfacial area is an efficient approach to enhance the electrochemical performance of supercapacitors but remains greet challenges in their synthesis.Herein,a novel ultra-small amorphous Fe2O3 nanodots/graphene heterostructure (a-Fe2O3 NDs/RGO) aerogel was facilely synthesized via excessive metal-ion-induced self-assembly and subsequent calcination route using Prussian blue/graphene oxide (PB/GO) composite aerogel as precursors.The deliberately designed a-Fe2O3 NDs/RGO heterostructure offers a highly interconnected porous conductive network,large heterostructure interfacial area,and plenty of accessible active sites,greatly facilitating the electron transfer,electrolyte diffusion,and pseudocapacitive reactions.The obtained a-Fe-2O3 NDs/RGO aerogel could be used as flexible frea-standing electrodes after mechanical compression,which exhibited a significantly enhanced specific capacitance of 347.4 F·g-1 at 1 A·g-1,extraordinary rate capability of 184 F·g-1 at 10 A·g-1,and decent cycling stability.With the as-prepared a-Fe2O3 NDs/RGO as negative electrodes and the Co3O4 NDs/RGO as positive electrodes,an all-solid-state asymmetric supercapacitor (a-Fe2O3 NDs/RGO//Co3O4 NDs/RGO asymmetric supercapacitor (ASC)) was assembled,which delivered a high specific capacitance of 69.1 F·g-1 at 1 A·g-1 and an impressive energy density of 21.6 W·h·kg-1 at 750 W·kg-1,as well as good cycling stability with a capacity retention of 94.3％ after 5,000 cycles.This work provides a promising avenue to design high-performance graphene-based composite electrodes and profound inspiration for developing advanced flexible energy-storage devices.