Nickel self-doped iron oxide/manganese carbonate hierarchical 2D/3D structures for electrochemical energy storage

We report a facile strategy to prepare (2D/3D) nickel self-doped NiFeOx@MnCO3 hierarchical nano heterostructured electrodes directly on Ni foam via in-situ hydrothermal method. We have demonstrated the hierarchical structures exhibit unique intercalation pseudocapacitance with surface redox contribution in overall charge storage process. The fabricated NiFeOx@MnCO3 electrode in aqueous electrolyte exhibited an enhanced specific capacity of 283 C g(-1) at 1 mA when tested in KOH electrolyte. The two-electrode symmetric cell delivered a specific energy of 18 W h kg(-1) at a power density of 236.1 W kg(-1) with good cycling stability of 92.7% after 2000 cycles. The hybrid supercapacitor is fabricated by assembling NiFeOx@MnCO3 with activated carbon delivered highest energy density of 50.38 W h kg(-1) at power density of 340.3 W kg(-1) with good cycling stability of 90% after 3000 cycles. (C) 2018 Elsevier Ltd. All rights reserved.