A three-dimensional pore-scale model for redox flow battery electrode design analysis

Journal Article · Mon Nov 28 00:00:00 UTC 2022 · Journal of Power Sources

DOI: https://doi.org/10.1016/j.jpowsour.2022.232329 · OSTI ID:1905130

Fu, Yucheng  ^[1]; Bao, Jie ^[1]; Zeng, Chao ^[1]; Chen, Yunxiang ^[1]; Xu, Zhijie  ^[1]; Kim, Soowhan ^[1]; Wang, Wei  ^[1]

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1. Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

A three-dimensional (3-D) pore-scale model has been developed to construct multiscale fibrous electrodes for redox flow batteries (RFB). New designs, such as biporous electrodes modify electrode structures by creating secondary pores on single carbon fiber to reduce internal battery resistance. Existing pore-scale models only resolve electrodes to the single carbon fiber scale and cannot incorporate recent multiscale electrode designs into numerical models. Our new model aims to bridge this gap and provide a tool to rapidly screen new electrode configurations. Two multiscale electrodes, laser-perforated and biporous electrodes, were investigated at varying operation conditions with the proposed 3-D pore-scale models. The laser-perforated electrode exhibits a reduced pressure drop, but follows the same permeability correlation compared to the corresponding pristine electrode. For the biporous electrode, the added specific surface area and faster reaction kinetics from the secondary pores are the most influential factors leading to improved battery efficiency. However, operating the biporous electrode in limiting current density conditions should be avoided due to the decreased mass transfer efficiency and a more significant voltage loss. Finally, we believe that our 3-D pore-scale model can accelerate the flow battery electrode design process and provide new insights into electrode geometry optimizations.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
• Sponsoring Organization: USDOE Laboratory Directed Research and Development (LDRD) Program
• Grant/Contract Number: AC05-76RL01830
• OSTI ID: 1905130
• Report Number(s): PNNL-SA-175492
• Journal Information: Journal of Power Sources, Journal Name: Journal of Power Sources Vol. 556; ISSN 0378-7753
• Publisher: ElsevierCopyright Statement
• Country of Publication: United States
• Language: English