Three-dimensional thermal-electrochemical-hydrodynamic numerical study of vanadium redox flow battery with different flow fields and non-homogeneously compressed electrode

This paper presents a concise 3D numerical study of Vanadium Redox Flow Batteries (VRFBs) with different flow field designs and non-homogeneously compressed electrodes. The model integrates mass, momentum, charge, and energy transport equations, including reaction kinetics for vanadium species. Four flow field designs (conventional, parallel, serpentine, and interdigitated) are evaluated for heat distribution uniformity. The model accounts for non-uniform electrode properties due to compression. Numerical results are validated against experimental data, exploring the impact of operating parameters such as current density, flow rate, and temperature on thermal behavior. The study also compares heat generated by electrochemical reactions, ohmic losses, and chemical activation across different flow fields. The findings revealed the highest temperature gradient and non-uniformity (in terms of temperature) with conventional designs followed by interdigitated, parallel and serpentine. Importantly, the study consistently highlights elevated temperatures in the discharge condition across all configurations. This emphasizes the need for precise temperature control to prevent VO₂+ precipitation. These insights from VRFB optimization efforts are thoroughly presented in this paper.