Topology optimization of 3D flow fields for flow batteries

TL;DR

This paper presents a topology optimization framework for designing three-dimensional flow fields in redox flow batteries, aiming to improve efficiency by reducing power losses and dead zones.

Contribution

It introduces a novel method to automatically generate optimized 3D flow fields for flow batteries, surpassing traditional heuristic design approaches.

Findings

Optimized 3D flow fields reduce electrical and flow pressure power losses.

Designs mitigate electrode dead zones and improve reactant distribution.

Framework automates flow field design, enhancing efficiency and reducing manual tuning.

Abstract

As power generated from renewables becomes more readily available, the need for power-efficient energy storage devices, such as redox flow batteries, becomes critical for successful integration of renewables into the electrical grid. An important component in a redox flow battery is the planar flow field, which is usually composed of two-dimensional channels etched into a backing plate. As reactant-laden electrolyte flows into the flow battery, the channels in the flow field distribute the fluid throughout the reactive porous electrode. We utilize topology optimization to design flow fields with full three-dimensional geometry variation, i.e., 3D flow fields. Specifically, we focus on vanadium redox flow batteries and use the optimization algorithm to generate 3D flow fields evolved from standard interdigitated flow fields by minimizing the electrical and flow pressure power losses. To understand how these designs improve performance, we analyze the polarization of the reactant concentration and exchange current within the electrode to highlight how the designed flow fields mitigate the presence of electrode dead zones. While interdigitated flow fields can be heuristically engineered to yield high performance by tuning channel and land dimensions, such a process can be tedious; this work provides a framework for automating that design process.