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

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.