Innovative polymer-based, miniaturized solid-state reference electrode: A sustainable solution for potentiometric and electrochemical power sources

Abstract

The rapid development of miniaturized energy storage systems, such as batteries and fuel cells, requires compact, stable, and liquid-junction-free reference electrodes for precise electrochemical characterization. This study presents a novel all-solid-state reference electrode (S-RE) based on polymeric ion exchangers embedded in a carbon-paste matrix, offering a sustainable solution for potentiometric and electrochemical power sources. The S-RE eliminates liquid junctions, providing superior stability, broad electrolyte compatibility, and ease of miniaturization, making it ideal for next-generation energy applications.

The polymeric ion exchangers in the S-RE ensure low solubility, high ion-exchange capacity, and strong mechanical and pH stability, making it compatible with various electrolytes. Electrochemical evaluations were performed in acidic, alkaline, neutral, and non-aqueous media, confirming the electrode's reliability. The optimized design, incorporating a cation-exchanger and an anion-exchanger, enhances stability and long-term performance in extreme environments.

Benchmarking against hydrogen reference electrodes and Hg/HgO electrodes validated its suitability for energy storage applications. Additionally, the S-RE demonstrated statistical equivalence to Ag/AgCl electrodes in the potentiometric determination of isoxsuprine (ISX). Its miniaturized design supports sample volumes as low as 500 μL, while its cost-effective fabrication makes it scalable for industrial applications, positioning the S-RE as a promising alternative for electrochemical diagnostics in energy storage and sensing technologies.