Engineered Porous Electrodes to Unlock Ultra-low Cost Fe-Air Redox Flow Batteries

Introduction

This proposal will develop a game-changing paradigm to design, synthesize, and functionalize porous electrode materials with far-reaching consequences in electrochemical science and engineering. Focusing on the Fe-air redox flow battery (FAIR-RFB), which holds promise for low-cost, long-duration energy storage, I will employ an interdisciplinary approach bridging (electro)chemical engineering, materials science, and computational design to address the following fundamental challenges:

Challenge 1: Porous Electrode Microstructure

1. I will elucidate the role of the porous electrode microstructure.
2. I will introduce a new methodology that couples evolutionary algorithms with microstructure-informed simulations to predict ideal electrode geometries.
3. A versatile synthetic platform, non-solvent induced phase separation, will be leveraged to synthesize highly controlled 3D microstructures and train neural networks to accelerate the discovery of optimal geometries.

Challenge 2: Surface Moieties Influence

1. I will determine to what extent surface moieties of the porous electrode influence transport phenomena, kinetics, and durability.
2. I will employ electrografting of select molecules to functionalize porous electrodes and impart functional properties (wettability, activity, stability).
3. I will perform nanoelectrochemical imaging to elucidate the role of electrode-coating-electrolyte phenomena.

Challenge 3: Electrochemical Reactor Architecture

1. I will develop a novel electrochemical reactor architecture for high-power Fe-air RFBs.
2. Building upon the two previous developments, I will synthesize tailored iron and air electrodes and leverage polymeric bipolar membranes to realize a high voltage and low resistance electrochemical cell.
3. Advanced imaging techniques, i.e., energy- and wavelength-selective neutron imaging, will be employed to visualize reactive transport phenomena during operation, thus helping to address these questions.

Conclusion

The novel approaches developed in FAIR-RFB will enable breakthroughs in performance and durability of large-scale electrochemical energy storage systems.