Bimetallic NiFe hydroxide coated onto commercial graphite foil as efficient supercapacitor electrode

Abstract

Attaining high specific energy meanwhile detaining the specific power achieved, is a significant challenge faced in modern era supercapacitors. Coupling two highly electroactive metal ions together in an array, holds sanguinity to attain high energy and power proficiencies. Ni(OH)2 being an economical battery-grade electrode material, has respectable charge-storage competence, but suffers from sluggish ion mobility. Benefitting from the lamellar structure and easy tunability of layered double hydroxide (LDH), swifter ion/electron mobility and improved conductivity is achievable. Herein this work, conductive iron (Fe) species incorporated with nickel hydroxide matrix to form LDH structure through facile coprecipitation strategy is proposed. The upshot of varying nickel iron ratio on the structural, functional, morphology and electrochemical characteristics is inspected. The best composition had an admirable specific capacity of 381 C g−1 (1368 F g−1) at 1 A g−1 with an ability to retain 87.5% of the initial capacity even after 5000 successive charge-discharge cycles. The symmetric supercapacitor developed using the optimal NiFe LDH over commercial graphite foil, furnishes a specific energy of 66.13 W h kg−1 at specific power 1483 W kg−1. Moreover, the corrosion and radiation inertness of commercial graphite foil, widens the scope of utilization of the fabricated supercapacitor.