Topology-Optimized Porous Electrode Architectures for Enhanced Performance in Vanadium Redox Flow Batteries in Flow-Through Cell Designs

Abstract

Herein, a comprehensive investigation is presented into the optimization of porous electrode (PE) structures in vanadium redox flow batteries (VRFBs) using topology optimization (TO) to enhance cell performance, particularly in flow-through configurations. This work builds upon prior studies by incorporating a full cell model that accounts for species transport, electrolyte flow, charge transfer, and proton transport within both positive and negative electrodes. PEs are optimized under different depths of discharge (DoD) conditions—5%, 50%, 65%, 90% and 95%—to capture the diverse requirements for reaction kinetics and mass transport under varying reactant concentrations. The optimized structures, featuring interdigitated channels on both electrodes, yield substantial improvements in mass transport and reaction rates compared to unmodified flow-through and interdigitated flow-field configurations. Performance tests, including polarization curves and charge/discharge characteristics, demonstrate superior current density and electrolyte utilization in the optimized flow-through porous electrode (OFT) designs. Among these, the OFT95% (optimized at 95% DoD) performs exceptionally well under low reactant conditions. Despite minor tradeoffs in hydraulic power loss, the optimized structures maintain competitive round-trip efficiency, showing promise for real-world applications. This study provides critical insights into electrode engineering for VRFBs, contributing to the advancement of sustainable energy storage technologies essential for achieving carbon neutrality.