Related Experiment Video
Updated: Aug 31, 2025

A Protocol for Electrochemical Evaluations and State of Charge Diagnostics of a Symmetric Organic Redox Flow Battery
Published on: February 13, 2017
Bromine Crossover in Operando Analysis of Proton Exchange Membranes in Hydrogen-Bromate Flow Batteries
Alexander Modestov1, Natalia Kartashova2, Roman Pichugov2
1Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, 119071 Moscow, Russia.
Abstract:
The manuscript deals with the fundamental problem of platinum hydrogen oxidation catalyst poisoning of the hybrid chemical power source based on bromate electroreduction and hydrogen electro-oxidation reactions. The poisoning is caused by the crossover of bromine-containing species through the proton exchange membrane separating compartments of the flow cell. Poisoning results in a drastic decrease in the flow cell performance. This paper describes the results of the direct measurement of bromine-containing species' crossover through perfluorosulfonic acid membranes of popular vendors in a hydrogen-bromate flow cell and proposes corresponding scenarios for the flow battery charge-discharge operation based on the electrolyte's control of the pH value. The rate of the crossover of the bromine-containing species through the membrane is found to be inversely proportional to the membrane thickness.
Related Concept Videos
Electrolysis
Halogenation of Alkenes
Consider the bromination of cyclopentene. Molecular bromine is polarized in the proximity of the π electrons of cyclopentene. An electrophilic bromine atom adds across the double bond, forming a cyclic bromonium ion intermediate.
Formation of Halohydrin from Alkenes
Electrophilic Aromatic Substitution: Chlorination and Bromination of Benzene
Radical Substitution: Allylic Bromination
Radical Anti-Markovnikov Addition to Alkenes: Overview

