Comparative Study of Individual and Mixed Aqueous Electrolytes with ZnFe₂O₄ Nano–flakes Thin Film as an Electrode for Supercapacitor Application

Abstract

In the present work, ZnFe2O4 nano‐flakes thin films are grown on stainless steel substrate using mechanochemical approach. The prepared thin films are characterized and used as working electrodes for supercapacitor application. Investigation for an ideal electrolyte is systematically carried out by comparing three aqueous electrolytes such as LiOH, NaOH, KOH (1 M) and their binary mixtures (1:1 v/v of 1 M each electrolyte) on the basis of their supercapacitive performances. Among the electrolytes, 1 M KOH is found to be an ideal electrolyte, which demonstrates higher specific capacitance (433 F g−1), cycle stability (91 % retention up to 4000 cycles), energy density (86 Wh kg−1), respectively. The binary mixtures of LiOH‐NaOH, NaOH‐KOH and LiOH‐KOH electrolytes show relatively less specific capacitance of 106, 146 and 180 F g−1, respectively. The use of mixed electrolytes and underlying factors affecting the performance are investigated in detail for the first time. The physical parameters such as conductivity, density, viscosity, contact angle and hydrated ionic radius of aqueous electrolytes influencing the specific capacitance of the ZnFe2O4 nano‐flakes based electrode is studied.

Facile Hydrothermal Synthesis of Hollow Fe3O4 Nanospheres: Effect of Hydrolyzing Agents and Electrolytes on Electrocapacitive Performance of Advanced Electrodes

“…However, Fe 3 O 4 electrodes display highest specific capacitance in KOH followed by NaOH and LiOH, Table 2 and Table 3. This result contrary to the expectation is explained on the basis of the ionic radii of hydrated ions [75,76]. The smaller ions, in fact, form larger hydrated ions.…”

Orange-Peel-Derived Carbon: Designing Sustainable and High-Performance Supercapacitor Electrodes

“…The diameter of the semicircle represented the charge transfer resistance at the double layer [51], which was decreasing in the following sequence, LiOH > NaOH > KOH. The lowest charge transfer resistance value in KOH electrolyte suggests that K + contributed to an efficient charge adsorptiondesorption process on the electrode-electrolyte interface due to its smaller hydrated ionic radius [52].…”

Marigold micro-flower like NiCo2O4 grown on flexible stainless-steel mesh as an electrode for supercapacitors

“…Cyclic voltammetry (CV), galvanostatic chargedischarge (GCD), and electrochemical impedance spectroscopy (EIS) were carried out in a standard three-electrode system with graphite and a saturated Ag/AgCl electrode as the counter and reference electrodes, respectively. The specic capacitance (C sp , F g À1 ), the energy density (E, W h kg À1 ), and power density (P, kW kg À1 ) were calculated according to the following equations: 40,41…”