Design of highly porous Fe(3)O(4)@reduced graphene oxide via a facile PMAA-induced assembly

Advances in the synthesis and processing of graphene-based materials have presented the opportunity to design novel lithium-ion battery (LIB) anode materials that can meet the power requirements of next-generation power devices. In this work, a poly(methacrylic acid) (PMAA)-induced self-assembly process was used to design super-mesoporous Fe(3)O(4) and reduced-graphene-oxide (Fe(3)O(4)@RGO) anode materials. We demonstrate the relationship between the media pH and Fe(3)O(4)@RGO nanostructure, in terms of dispersion state of PMAA-stabilized Fe(3)O(4)@GO sheets at different surrounding pH values, and porosity of the resulted Fe(3)O(4)@RGO anode. The anode shows a high surface area of 338.8 m(2) g(−1) with a large amount of 10–40 nm mesopores, which facilitates the kinetics of Li-ions and electrons, and improves electrode durability. As a result, Fe(3)O(4)@RGO delivers high specific-charge capacities of 740 mA h g(−1) to 200 mA h g(−1) at various current densities of 0.5 A g(−1) to 10 A g(−1), and an excellent capacity-retention capability even after long-term charge–discharge cycles. The PMAA-induced assembly method addresses the issue of poor dispersion of Fe(3)O(4)-coated graphene materials—which is a major impediment in the synthesis process—and provides a facile synthetic pathway for depositing Fe(3)O(4) and other metal oxide nanoparticles on highly porous RGO.