Journal Article

Insights into novel indium catalyst to kW scale low cost, high cycle stability of iron-chromium redox flow battery

Niu, Yingchun, Xu, Chunming, Wu, Guangfu, Peng, Bo, Guo, Chao, Lv, Wenjie, Liu, Yinping, Heydari, Ali, Xu, Quan, Zhou, Tianhang

2025

Overview

Iron-chromium flow batteries (ICRFBs) have emerged as an ideal large-scale energy storage device with broad application prospects in recent years. Enhancement of the Cr3+/Cr2+ redox reaction activity and inhibition of the hydrogen evolution side reaction (HER) are essential for the development of ICRFBs and require a novel catalyst design. However, elucidating the underlying mechanisms for modulating catalyst behaviors remains an unresolved challenge. Here, we show a novel precisely controlled preparation of a novel thermal-treated carbon cloth electrode with a uniform deposit of low-cost indium catalyst particles. The density functional theory analysis reveals the In catalyst has a significant adsorption effect on the reactants and improves the redox reaction activity of Cr3+/Cr2+. Moreover, H+ is more easily absorbed on the surface of the catalyst with a high migration energy barrier, thereby inhibiting the occurrence of HER. The assembled ICRFBs have an average energy efficiency of 83.91% at 140 mA cm−2, and this method minimizes the electrodeposition process and cleans the last obstacle for industry long cycle operation requirements. The ICRFBs exhibit exceptional long-term stability with an energy efficiency decay rate of 0.011% per cycle at 1000 cycles, the lowest ICRFBs reported so far. Therefore, this study provides a promising strategy for developing ICRFBs with low costs and long cycle life. Schematic diagram of the ICRFBs and the fabrication of the electrode. [Display omitted] •A novel thermal-treated carbon cloth electrode with a uniform deposit of low-cost indium catalyst particles.•DFT simulation explains the mechanism of In catalysts to enhance Cr3+/Cr2+ reaction activity and inhibit HER.•We successfully demonstrated the scale-up from laboratory-level experiments to a kW-scale stack.

• Publisher: Elsevier B.V,KeAi Publishing Communications Ltd,KeAi Communications Co., Ltd
• Subject: Alternative energy sources / Batteries / Carbon / Catalysts / Chromium / Cycle stability / Decay rate / Density functional theory / Electrodes / Electrolytes / Energy efficiency / Energy storage / Evolution / Heat / Hydrogen / Hydrogen evolution / Hydrogen evolution side reaction / In catalyst / Indium / Industry usage / Iron / Iron-chromium flow batteries / Low cost / NMR / Nuclear magnetic resonance / Redox reactions / Renewable resources / Spectrum analysis / Stability