Inkjet-printed microband electrodes for a cost-efficient state-of-charge monitoring in redox flow batteries

• Published in: Sensors and actuators. B, Chemical Vol. 369; p. 132291
• Main Authors: Zub, Karina, Stolze, Christian, Rohland, Philip, Stumpf, Steffi, Hoeppener, Stephanie, Hager, Martin D., Schubert, Ulrich S.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 15.10.2022; Elsevier Science Ltd
• Subjects: Battery; Electrical measurement; Electrodes; Electrolytes; Inkjet; Inkjet printing; Inks; Iron cyanides; Measurement methods; Microband; Microelectrode; Microelectrodes; Prototyping; Rechargeable batteries; Sputtering; State of charge; State-of-charge; Microelectrode; Inkjet; Microband; Sputtering; Battery
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2022.132291

A readily available prototyping process for the fabrication of low-cost microband electrodes is introduced, which are applicable for the accurate amperometric state-of-charge (SOC) measurement in redox flow battery (RFB) electrolytes. For this purpose, an inexpensive and straightforward inkjet printing of conductive platinum-based and insulating polymer-based inks was investigated. The overall inkjet-printed microband electrode performance in 0.4 M ferri-/ferrocyanide with 0.5 M KCl as supporting electrolyte were compared to sputter-coated microband electrodes and commercial disk microelectrodes using an SOC measurement method based on steady-state amperometry. Absolute root-mean-square deviations (RMSD) are below 1.04% SOC for the printed microband electrodes. The low material costs of about €2.52 (USD2.86) for the presented prototype and the simplicity of the fabrication process could facilitate a widespread application of the amperometric SOC measurement in RFBs. •Amperometric state-of-charge monitoring of redox flow battery electrolytes is highly accurate.•Commercial disk microelectrodes demand low-current measurement capabilities and are expensive.•Microband electrodes provide larger electrode surfaces and easily detectable currents.•Microbands can be fabricated at the cross-section of nano-/microlayered structures.•Printing techniques can be used for the low-cost prototyping of microband electrodes.