A 2D Thermal Model of Stacked Vanadium Redox Flow Batteries for Efficient Thermal Management

Abstract

In an industrial‐scale vanadium redox flow battery system, cells are stacked to form a compact module that serves as the power system's most fundamental unit in its scale‐up. Considering the narrow temperature range restricted by the precipitation of vanadium ions in the electrolyte and the relatively strong current employed, heat generation and dissipation determine the stack's temperature, significantly affecting the performance. Using the mass, momentum, energy conservation, electrochemical kinetics in each cell, and circuit analysis in the manifolds and channels through which electrolyte flows and is distributed to each cell, a 2D thermal model is developed in this study to investigate the temperature distribution and variation within the cell stack. Benefit from the integrated simulation of a 2D model and analytical circuit in flow frames in the stack, the temperature distribution and hotspots within the stack during the dynamic charge–discharge cycles can be precisely determined. In the results, it is indicated that the global consideration of transport and electrochemical processes demonstrate a more systematic understanding of heat generation and transfer throughout the stack.