Binder-free three-dimensional porous Mn3O4 nanorods/reduced graphene oxide paper-like electrodes for electrochemical energy storage

Abstract

This research demonstrates novel flexible and binder-free Mn₃O₄ nanorods (NRs)/reduced graphene oxide (rGO) hybrid papers with unique three-dimensional nanoporous networks were fabricated by filtration and a hydrothermal reduction process, where rGO acts not only as a flexible substrate but also as an electron conductor. The three-dimensional nanoporous networks were generated by the homogeneous intercalation of Mn₃O₄ NRs into the lamellar rGO layers, which exhibited excellent mechanical stability and provided electrically conducting channels to promote electrolyte penetration when used as electrodes for Li-ion batteries (LIBs) and supercapacitors. The prepared Mn₃O₄ NRs/rGO hybrid lamellar papers demonstrated excellent cyclic retention with the specific capacity of 669.6 mA h g⁻¹ after 100 cycles in LIBs, which is 9 times higher than 65.8 mA h g⁻¹ of γ-MnOOH/Mn₃O₄ mixed phase nanorods. Additionally, the three-dimensional porous hybrid Mn₃O₄ NRs/rGO papers also exhibit superior specific capacitance of 204.2 F g⁻¹, two times higher than that of γ-MnOOH/Mn₃O₄ mixed phase nanorods, and only decreases by 10% after 2000 cycles in the supercapacitor. These Mn₃O₄ NRs/rGO papers hold promising potential for flexible electrochemical energy storage devices.