Iron-based electrodes have attracted great attention for sodium storage because of the distinct cost effec-tiveness.However,exploring suitable iron-based electrodes with high power density and long duration remains a big challenge.Herein,a spray-drying strategy is adopted to construct graphene-coated Na2.4Fe1.8(SO4)3 nanograins in a 3D graphene microsphere network.The unique structural and composi-tional advantages endow these electrodes to exhibit outstanding electrochemical properties with remarkable rate performance and long cycle life.Mechanism analyses further explain the outstanding electrochemical properties from the structural aspect.