Performance insights of reversible chlor-alkali cells for renewable energy storage utilizing environmentally friendly non-fluorinated membranes
This study focuses on testing of a more sustainable proton exchange membrane-based reversible unitized electrochemical cell for hydrogen production, storage, and reuse through chlor-alkali process. Through this process, in electrolysis mode H2, Cl2, and NaOH are produced. These products can then be...
| Autores: | , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2025 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | RUIdeRA. Repositorio Institucional de la UCLM |
| OAI Identifier: | oai:ruidera.uclm.es:10578/47734 |
| Acceso en línea: | https://doi.org/10.1016/j.ijhydene.2025.05.341 https://hdl.handle.net/10578/47734 |
| Access Level: | acceso abierto |
| Palabra clave: | Chlor-alkali systemEDEN® technology Energy storageH2 efficiency PVA membranes Positron annihilation lifetime spectroscopy (PALS) |
| Sumario: | This study focuses on testing of a more sustainable proton exchange membrane-based reversible unitized electrochemical cell for hydrogen production, storage, and reuse through chlor-alkali process. Through this process, in electrolysis mode H2, Cl2, and NaOH are produced. These products can then be reused to generate electricity in an H2/Cl2 fuel cell. Additionally, the system can function as an electrochemically assisted gas-liquid absorption unit, to support CO2 fixation. The membranes were prepared using eco-friendly materials by cross-linking PVA with chitosan (Cs). These membranes were integrated into specially designed reversible electrochemical cells, which were manufactured using 3D printing technology. The cells efficiently converted renewable energy into hydrogen and chlorine and vice versa. The effect of Cs concentration on the performance of the electrochemical cell in both electrolysis and H2/Cl2 fuel cells modes was investigated by switching between these modes at room temperature, over two cycles of 2 h each. It was observed that increasing Cs concentrations in the cross-linked PVA membranes resulted in decreased power consumption during electrolysis mode, while maintaining a Faraday efficiency exceeding 95 %. Moreover, it enhanced the power density achieved by the H2/Cl2 fuel cell, reaching approximately 1.8 mW/cm2, a value comparable to that of the commercially available Nafion 117 membrane tested under identical conditions. By studying the free volume structure of the membranes using positron annihilation spectroscopy (PALS), it was found that higher Cs concentrations resulted in an increase in the free volume within the membranes. This increase in the hole size was found to directly influence the permeability of chlorine species through the membranes. The obtained results highlights the feasibility of using cross-linked non-fluorinated PVA/Cs membranes in renewable energy storage systems based on chlor-alkali reversible cells. |
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