Investigation of capacitor electrolyte performance of green synthesized Ni, Mg, and <scp>NiMg</scp> ‐citrates

Abstract Ni‐citrate, Mg‐citrate, and bimetallic NiMg‐citrate complexes with equal molarities of Ni and Mg were synthesized using a green synthesis method to develop alternative electrolyte materials for capacitors. The synthesis was microwave‐assisted using NiSO 4 , MgSO 4 , citric acid, acetic acid, distilled water, and ethanol as starting materials. Each complex electrolyte material was prepared as a 1% distilled water solution and used as electrolytes in the capacitor cell formed by the two‐electrode method. Electrochemical performance evaluations were conducted using Cyclic Voltammetry (CV) and Electro Impedance Spectroscopy (EIS) analyses. Results showed significant differences in the materials' capacitive and electrochemical behavior. The redox reaction occurring in two regions (0.17 V and 0.45 V) with the Mg‐citrate structure was observed only at 0.47 V levels with Ni dominance in the NiMg‐citrate complex electrolyte. Cycle life analysis showed that the NiMg‐citrate electrolyte is the second ideal structure after Mg‐citrate at low scan rates, while at 50 mV s −1 and above, this performance is below the Ni‐citrate electrolyte. The highest discharge capacitance value of 378 mF cm −2 was obtained in the Mg‐citrate electrolyte. The findings show that Ni and Mg containing citrate complexes produced by green synthesis can be evaluated as eco‐friendly, low‐cost electrolyte alternatives.