Comparative Analysis of Aloe Vera and Orange Peel Extracts as Sustainable Electrolytes in a Copper–Zinc Bio-Electrochemical Cell

The need for sustainable energy storage has prompted the study of bio-derived electrolytes as a substitute for traditional battery systems. This paper compares aloe vera and orange peel extracts as natural electrolytes in a 3-compartment copper-zinc electrochemical cell. Voltage output and stability of the electrolytes were analyzed and compared across five dilution ratios (1:1–1:5) under constant conditions. Plant extracts were prepared by blending, dilution with distilled water, and filtration to obtain aqueous electrolytes. Voltage output was recorded on a digital multimeter over seven days to check the stability of the system. The two electrolytes yielded measurable and sustained voltages, which suggested their potential use as natural electrolytes in electrochemical systems. The voltage output was not linearly related to the dilution. The greatest mean voltage was recorded with aloe vera at the 1:1 ratio (1.393 V) and at the ratios of 1:2, 1:3, and 1:5 (1.280–1.294 V). Orange peel achieved its best mean voltage with the most dilute 1:5 ratio (1.314 V) and similar results at 1:1-1:3 (1.166-1.243 V). The performance of both electrolytes was found to be lower at a 1:4 ratio. The results show that the performance of the electrolytes depends on both concentration and properties, including ionic conductivity, viscosity, pH, and interaction with the electrodes. The results support the potential of plant-based electrolytes in Cu-Zn systems and emphasize the need to optimize dilution and composition to improve electrochemical performance.