Water electrolysis rebalancing method for capacity recovery of iron chromium flow batteries
LI Jinghao
YUAN Meile
ZHANG Rong
LI Xiaomeng
WANG Liping
LIU Yong
NIU Shiyang
Abstract：The iron-chromium flow battery accumulates Fe3+ions in the positive electrolyte due to the hydrogen evolution side reaction,resulting in a gradual increase in valence state and capacity loss.Traditional rebalancing techniques often involve the consumption of reducing agents,which lead to the generation of chlorine gas in a hydrochloric acid environment,posing challenges for practical engineering applications.In response to this issue,the paper propose a rebalancing device and capacity restoration method based on water electrolysis.The rebalancing cell comprises an oxygen-evolving electrode for the positive electrode,supported Pt/C catalyst,and a conventional flow battery structure for the negative electrode.Suitable materials and operating parameters were determined through research that verified the reduction effect of a water electrolysis capacity restoration device on positive electrode electrolyte,as well as its impact on iron-chromium flow battery performance.The experiment indicate that the rebalancing method can restore over 90% of more than 20% decayed electrolytes while maintaining energy efficiency at approximately 79%under conditions of 80 mA cm-2.Additionally,this water electrolysis capacity restoration device can be integrated with iron-chromium flow batteries for multiple capacity recovery operations,offering a safe and pollution-free new approach.
Keywords：iron-chromium flow batterycapacity recoveryrebalancewater electrolysiselectrochemistry
Publication Date：2026-02-25
Online Publishing Date：2026-03-13(First online date of this platform, not the publication date of the document)
Pages：6( 59-64 )