Nickel ferrite beehive-like nanosheets for binder-free and high-energy-storage supercapacitor electrodes

摘要

Herein, we present the facile growth of beehive-like NiFe2O4 nanosheets over Ni nanocones for shorter electron transport distances in supercapacitor electrodes. The electrodeposited ultrathin nanosheets provide excellent electrode-electrolyte interfacial areas, thereby enabling superior electrochemical performances. Notably, the deposition duration is tuned to achieve abundant energy storage sites and controlled cavities for adequate electrolytic ion diffusion. The synergy of these advantageous cavities and active sites of beehive-like NiFe2O4 nanosheets yields excellent stability with a capacitance retention of 95.3% after 10, 000 charging and discharging cycles of the nanosheet-based supercapacitor electrodes. At a high galvanostatic current rate of 5 A g(-1), the capacitance was 483 F g(-1). The optimal two-dimensional ultrathin NiFe2O4 beehive nanostructure exhibits immense potential for high-energy-storage supercapacitor electrodes, paired with the required pseudocapacitive characteristics. (C) 2020 Elsevier B.V. All rights reserved.