Potassium-ion aqueous supercapattery composed by solar carbon and nickel-zinc prussian blue analogue

• Published in: Journal of energy storage 2020-10, Vol.31, p.101667, Article 101667
• Main Authors: Lobato-Peralta, Diego Ramón, Vazquez-Samperio, Juvencio, Pérez, Obed, Acevedo-Peña, Próspero, Reguera, Edilso, Cuentas-Gallegos, Ana Karina
• Format: Article
• Language: English
• Subjects: Activated carbon; Electrochemical energy storage; K-ion supercapattery; Prussian blue analogues; Solar carbon
• ISSN: 2352-152X; 2352-1538
• DOI: 10.1016/j.est.2020.101667

•Relative abundant raw materials were employed to obtain double layer solar carbon and faradaic Ni-ZnHCF.•Solar carbon can reach more than 215 F g−1 and exhibits excellent rate capability.•Mixed Ni-ZnHCF exhibited paramount performance compare to single PBAs.•Electrodes exhibit similar rate capability and energy storage capacity.•Assembled K-ion supercapattery shows excellent stability evaluated by GCD and EIS. Hybrid energy storage devices, currently known as supercapatteries, combine electrodes with two different energy storage mechanisms, double-layer and fast-kinetics faradaic processes, to deliver high specific energy at high specific power. Here, an eco-friendly synthetic route is employed to obtain negative (solar carbon) electrode, and a soft–chemistry route to synthesize positive (nickel-zinc hexacyanoferrate) electrode, to assemble a K-ion aqueous supercapattery. Activated carbon was synthesized by pyrolysis of agro-industrial waste composed by agave angustifolia leaves in a solar furnace, and mixed nickel-zinc hexacyanoferrate was prepared by simple chemical precipitation. Conventional three-electrode characterization of active materials showed that both materials exhibit similar rate capability and charge storage capacities. A supercapattery was obtained when combining these two electrodes, delivering specific energies of 9.163 W h kg−1 and 6.444 W h kg−1 at specific power values of 0.153 kW kg−1 and 5.638 kW kg−1, respectively. The assembled K-ion energy storage device retained 85% of the initial capacitance after 5000 cycles (at 2.5 Ag−1), with a coulombic efficiency close to 100%. [Display omitted]