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

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 g-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 g-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.