Facile preparation of a three-dimensional Fe3O4/macroporous graphene composite for high-performance Li storage

Abstract

A three-dimensional macroscopic Fe₃O₄/porous graphene (FPG) composite was prepared by a facile self-assembly method at room temperature using polystyrene spheres as templates, followed by calcination treatment. FPG with a 3D macroporous graphene framework tightly anchored with Fe₃O₄ nanoparticles (NPs) ensures a reversible reaction and fast electron/Li⁺ transport of the FPG electrode. Benefiting from the interconnected graphene framework and macropores, the FPG electrode shows a decreasing SEI and contact resistances during long-term cyclic tests with lower contact resistance and faster Li⁺ diffusion compared to the contrastive Fe₃O₄/GS composed of numerous 2D hybrid sheets. As an anode material for LIBs, FPG exhibits superb rate capabilities (1057, 843, 709, 569 and 500 mA h g⁻¹ at current densities of 200, 400, 800, 2000 and 4000 mA g⁻¹) and excellent long-term cyclic performance of 859 mA h g⁻¹ after 1000 cycles at 2 A g⁻¹ rate, which is much better than that of Fe₃O₄/GS.