(706c) Flow Field Geometry and Electrode Structure Optimization of Redox Flow Batteries through Analytical Modeling and Dimensional Analysis

Redox flow batteries (RFBs) have emerged as a potential large-scale energy storage system (ESS) for integrating with intermittent renewable energy sources such as solar, wind, and wave power. RFBs feature decoupled energy and power units, offering design flexibility alongside longevity (>10 years) and operational safety; however, RFBs exhibit relatively low energy density and, hence, are expensive compared to other mainstream ESS (e.g., lithium-ion, regenerative fuel cells). Since flow fields and electrodes play significant roles in the electrochemical performance of RFBs, both must be carefully tailored for optimal performance.

Providing accurate analytical or semi-analytical models for RFBs with rapid response and insightful trends is necessary. Additionally, as RFBs vary in size and design based on the application requirements, developing and reporting results using dimensionless parameters is necessary first to globalize the results and, secondly, to identify the dominant phenomenon in describing the performance of RFBs as electrochemical reactors.

In our previous work¹, we have developed a semi-analytical fluid dynamics model, abbreviated as HEAM, capable of modeling both SFF and IFF. The HEAM provided the foundations for further integration of mass transport and kinetics and, ultimately, performance prediction of RFBs. Additionally, we have performed a dimensional analysis of the fluid dynamics of RFBs, which can be extended further to the mass transport and kinetics to provide a full picture of influential dimensionless parameters on the system. This study focuses on providing a comprehensive description of the RFB system and suggesting optimal flow field geometry and electrode properties.

References

1. Asadipour, E. & Ramani, V. K. A computationally-cost effective model for fluid flow in redox flow batteries. AIChE J 69, e18051 (2023).