Mirghni, Abdulmajid AbdallahMomodu, Damilola Y.Oyedotun, Kabir OyeniranDangbegnon, Julien K.Manyala, Ncholu I.2018-07-262018-09Mirghni, A.A., Momodu, D., Oyedotun, K.O. et al. 2018, 'Electrochemical analysis of Co3(PO4)2·4H2O/graphene foam composite for enhanced capacity and long cycle life hybrid asymmetric capacitors', Electrochimica Acta, vol. 283, pp. 374-384.0013-4686 (print)1873-3859 (online)10.1016/j.electacta.2018.06.181http://hdl.handle.net/2263/65985In this paper, we explore the successful hydrothermal approach to make Co3(PO4)2·4H2O/GF micro-flakes composite material. The unique sheet-like structure of the graphene foam (GF) significantly improved the conductivity of the pristine Co-based material, which is a key limitation in supercapacitors application. The composite electrode material exhibited superior capacitive conduct in 6 M KOH aqueous electrolyte in a 3-electrode set-up as compared to the pristine cobalt phosphate material. The material was subsequently adopted as a cathode in an asymmetric cell configuration with carbonization of Fe cations adsorbed onto polyaniline (PANI) (C-Fe/PANI), as the anode. The Co3(PO4)2·4H2O/GF//C-FP hybrid device showed outstanding long life cycling stability of approximately 99% without degradation up to 10000 cycles. A specific energy density as high as 24 W h kg−1, with a corresponding power density of 468 W kg−1 was achieved for the device. The results demonstrated the efficient utilization of the faradic-type Co3(PO4)2·4H2O/GF composite along with a functionalized carbonaceous electric double layer (EDL)-type material to produce a hybrid device with promising features suitable for energy storage applications.en© 2018 Elsevier Ltd. All rights reserved. Notice : this is the author’s version of a work that was accepted for publication in Electrochimica Acta. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. A definitive version was subsequently published in Electrochimica Acta, vol. 283, pp. 374-384, 2018. doi : 10.1016/j.electacta.2018.06.181.Graphene foam (GF)Electric double layer (EDL)Cobalt phosphateIron-carbonized polyanilineHybrid capacitorsEnergy storageFoamsSpecific energy densitySheet-like structureElectrochemical analysisComposite electrodeAsymmetric capacitorsSupercapacitorPotassium hydroxidePositive ionsPolyanilineGrapheneElectrolytesElectrochemistryElectrochemical electrodesCobalt depositsCobalt compoundsCathodesCarbonizationAnodesPostprint Article