High performance advanced asymmetric supercapacitor based on ultrathin and mesoporous MnCo2O4.5-NiCo2O4 hybrid and iron oxide decorated reduced graphene oxide electrode materials

• Published in: Electrochimica acta 2018-09, Vol.283, p.438-447
• Main Authors: Halder, Lopamudra, Maitra, Anirban, Das, Amit Kumar, Bera, Ranadip, Karan, Sumanta Kumar, Paria, Sarbaranjan, Bera, Aswini, Si, Suman Kumar, Khatua, Bhanu Bhusan
• Format: Article
• Language: English
• Subjects: Asymmetric supercapacitor; Cyclic stability; Energy density; Fe-rGO; MCO/NCO
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2018.06.184

Herein, we demonstrate a facile fabrication of nickel cobalt oxide nanoflake decorated manganese cobalt oxide nanostick-arrays (MnCo2O4.5-NiCo2O4), as a hybrid electrode material through multistep hydrothermal protocols for high performance power device applications. Iron oxide nanoparticles decorated reduced graphene oxide (Fe-rGO) was synthesized through a simplistic reduction process of GO. The morphological features, specific surface areas and morphology dependent electrochemical activity of the as-prepared electrode materials have been investigated systematically. Our as-prepared manganese cobalt oxide/nickel cobalt oxide, MnCo2O4.5-NiCo2O4 (abbreviated as MCO/NCO) hybrid electrode reveals a highest specific capacitance (Cs) value of ∼2506 F g−1 as compared to the base MnCo2O4.5 (∼1220 F g−1) at 1 A g−1 constant current density. The higher Cs values of the hybrid composite can be credited to the synergistic property of MCO and NCO, which eventually facilitates electron transportation. In contrast, Fe-rGO shows a Cs value of ∼236 F g−1 at 1 A g−1. Moreover, an advanced asymmetric supercapacitor (ASC) device was fabricated utilizing MCO/NCO as positive and Fe-rGO as a negative electrode in presence of a potassium hydroxide (KOH) soaked laboratory Whatman 40 filter paper as separator. The device exhibits a Cs value of 170.8 F g−1 at 1 A g−1 together with a decent energy density of ∼34 Wh kg−1 (power density of 597.18 W kg−1 at 1 A g−1) and a longtime cyclic stability (90% Cs retention after 3000 Galvanostatic charge-discharge series). These results suggest superior application potential of our ASC for next -generation portable energy storage applications. [Display omitted] •MnCo2O4.5-NiCo2O4 electrode material was prepared by a facile hydrothermal protocol.•Fe-rGO was synthesized by a low temperature reduction method.•The device was fabricated utilizing MnCo2O4.5-NiCo2O4 as cathode and Fe-rGO as an anode.•MnCo2O4.5-NiCo2O4//Fe-rGO exhibits superior electrochemical activity.