Manganese ferrite/reduced graphene oxide composites as energy storage electrode materials for supercapacitors

Reduced graphene oxide has excellent mechanical properties, environmental friendliness, excellent electrical and thermal conductivity, but its self-agglomeration phenomenon limits its application in energy storage. Combining it with transition metal oxides is an effective way to adjust the growth structure, prevent agglomeration, and improve capacity. In this work, manganese ferrite/reduced graphene oxide (MnFe2O4/rGO) nanocomposite electrode materials were prepared by a one-step hydrothermal method. MnFe2O4 nanorods are uniformly dispersed on rGO sheets, and embedding between adjacent rGO layers can ensure good interfacial interaction and prevent rGO agglomeration. This unique arrangement resulted in enhanced charge transfer properties within the composites. The samples underwent characterization using X-ray diffraction (XRD), Transmission electron microscopy (TEM), scanning electron microscopy (SEM), Brunauer-Emmett-Teller analyzer (BET), and X-ray photoelectron spectroscopy (XPS). Subsequently, the physical properties of MnFe2O4/rGO were thoroughly investigated. The MnFe2O4/rGO nanocomposite exhibited a specific capacity of 195 F g-1 under a current density of 1 A g-1. Moreover, it demonstrated exceptional cycle stability, retaining 75.22% of its initial capacitance after 4000 charge-discharge cycles at 2 A g(-1). Notably, the asymmetric supercapacitor (ASC) device achieved an energy density of 16 W h kg-1 at a power density of 1280 W kg(-1). Additionally, the ASC device displayed remarkable cycling stability, preserving 73.78% of its capacitance after 5000 cycles. The results highlight the enhanced performance of MnFe2O4/rGO nanocomposites compared to individual MnFe2O4 (77 F g(-1)) and rGO (67 F g-1).