Rantho, Mologadi NkiyasiMadito, M.J. (Moshawe)Oyedotun, Kabir OyeniranTarimo, Delvina JaphetManyala, Ncholu I.2020-10-152020-10-152020-06Rantho, M.N., Madito, M.J., Oyedotun, K.O. et al. 2020, 'Hybrid electrochemical supercapacitor based on birnessite-type MnO2/carbon composite as the positive electrode and carbonized iron-polyaniline/nickel graphene foam as a negative electrode', AIP Advances, vol. 10, no. 6, art. 065113, pp. 1-14.2158-3226 (online)10.1063/5.0011862http://hdl.handle.net/2263/76476In this work, a birnessite-type MnO2/carbon composite with hierarchical nanostructures was synthesized using KMnO4 solution and spent printing carbon grains. A hybrid electrochemical supercapacitor device was fabricated based on the birnessite-type MnO2–carbon composite electrode and carbonized iron-polyaniline/nickel graphene foam as positive and negative electrodes, respectively. At the lowest specific current of 1.0 A g−1 and cell potential of 2.2 V in 2.5M KNO3 electrolyte, the device displayed a high energy and power density of 34.6 W h kg−1 and 1100.0 W kg−1 , respectively. The device further displayed long-term cycling stability with a capacitance retention of 98% over 10 000 galvanostatic charge–discharge cycles at 10 A g−1 . This device displays the overall excellent electrochemical performance.en© 2020 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license.ElectrodeCarbonEnergyHybridArticle