In recent times, demand for portable electronic devices like mobile phones, cameras and laptops etc. is increasing day by day. Energy storage devices such as batteries and supercapacitors have significant importance because of their high energy density and high power density, respectively.1 Supercapacitor is gaining great amount of attention because it uses less toxic material, offers high power density, excellent electrochemical stability, wide range of operating temperatures and durability. A facile fabrication of low cost, efficient, stable, eco-friendly and earth-abundant electrode materials for supercapacitors is critical.2 Layered double hydroxide (LDH) is new class of material having positively charged hydrotalcite-like layers, weakly bound, intercalating charge compensating anions and water molecules, has showed enormous supercapacitive performance.Layered double hydroxide (LDH) is new class of material having general formula (where, M2+ and M3+ are the bivalent and trivalent metal cations and An- is the charge balancing anion of valence n; ), has showed enormous supercapacitive performance.3 In this work, an ionic lamellar, two-dimensional (2D) nickel-iron layered double hydroxide (NiFe LDH) nanosheets over Ni foam have been synthesized via facile, cost effective and potentially scalable hydrothermal method. The as-prepared 2D NiFe-LDH nanosheets on nickel foam (NF/NiFe-LDH) was used as supercapacitor electrode. The electrochemical characterization techniques such as cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS) were used to characterize the material for its electrochemical properties, while SEM, TEM, XRD, BET, and XPS etc. techniques have been used for their morphological, structural and physical characterization. High specific capacitance of 700 F g-1 at 1 A g-1 was observed in three-electrode system using 2 M KOH as electrolyte. This work signifies great potential for low cost and eco-friendly NiFe LDH nanosheets as supercapacitor material.
Keywords: Supercapacitor; layered double hydroxide; energy storage
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