Devising of a method for improving anode capacity for an all-iron flow battery

Abstract

A comprehensive study of the impact of electrode design and iron deposition mechanism on the enhancement of the capacity of an all-iron redox flow battery (AIFB) has been conducted. The research is focused on revealing the complex interaction between electrode architecture, iron deposition behaviour, and battery capacity. Using a developed experimental setup, five different electrode designs are investigated. These designs include variations in the arrangement of carbon felt (CF) and non-woven fabric (NWF) layers and critical factors affecting iron deposition. Battery charge and discharge experiments were carried out under controlled conditions, simulating practical operating regimes with a current density of 50 mA/cm² and a compression ratio of 80%. The results demonstrate the influence of electrode design on iron deposition and, consequently, on battery capacity. The electrode configuration with two layers of CF and two layers of NWF exhibits a specific capacity exceeding 700 mA·h/cm². Analysis using scanning electron microscopy (SEM) complements the capacity determination results by providing valuable information about the spatial distribution of iron on the electrode surfaces. Furthermore, quantitative analysis using ZAF correction reveals uniform models of iron deposition on the surface of electrode E, indicating its potential for optimizing AIFB performance. This study provides a comprehensive understanding of the relationship between electrode design, iron deposition behaviour, and AIFB capacity. The results offer insights for improving electrode configurations, ultimately contributing to the development of efficient energy storage solutions