What is Limiting the Potential Window in Aqueous Sodium-Ion Batteries?

Application: Aqueous Sodium-Ion Batteries.

Instrument: HPR-40 DEMS.

Cell: ECL-Static.

Configuration: Battery electrodes analysed in the ECL-Static cell during electrochemical cycling.

Key Capabilities: Quantitative gas analysis, calibration, real-time degradation studies, simultaneous H₂, O₂ and CO₂ detection.

Understanding when gas evolution begins is essential for improving the safety and lifetime of aqueous batteries, yet conventional electrochemical measurements often fail to distinguish between useful electrochemical reactions and parasitic side reactions. In this study, the Hiden HPR-40 DEMS combined with the ECL-Static electrochemical cell was configured as a flow cell and used to continuously monitor hydrogen, oxygen and carbon dioxide evolution during cycling of aqueous sodium-ion battery electrodes.

Following calibration of the DEMS response, the HPR-40 provided quantitative measurements of H₂, O₂ and CO₂ evolution, allowing the onset potentials for individual gas-evolving reactions to be determined with high accuracy. The measurements showed that gas evolution begins at significantly lower potentials than suggested by cyclic voltammetry alone and identified carbon black oxidation as an unexpected source of CO₂ before the onset of oxygen evolution. By directly measuring the evolved gases, the authors were able to distinguish electrode degradation from electrolyte decomposition and obtain a much clearer understanding of the factors limiting the practical voltage window of aqueous sodium-ion batteries.

This paper demonstrates how the HPR-40 DEMS extends beyond electrocatalysis to provide a powerful quantitative diagnostic tool for battery research, degradation studies and safety investigations.

Why read this paper?

It is an excellent demonstration of calibrated DEMS for identifying degradation mechanisms and accurately determining gas evolution limits in advanced battery systems.

Paper Reference: Winkler, D., Stüwe, T., Werner, D., Griesser, C., Thurner, C., Stock, D., Kunze‐Liebhäuser, J. and Portenkirchner, E. (2022). What is limiting the potential window in aqueous sodium‐ion batteries? Online study of the hydrogen‐, oxygen‐ and CO₂‐evolution reactions at NaTi₂(PO₄)₃ and Na_0.44MnO₂ electrodes. Electrochemical Science Advances, 3(6). 

📖Read the paper here.

‌📩For further details, technical support, or to discuss your application, please contact us.