High energy density electrolytes for H₂/Br₂ redox flow batteries, their polybromide composition and influence on battery cycling limits.

ABSTRACT: Hydrogen-bromine redox flow batteries (H₂/Br₂-RFB) are a promising stationary energy storage solution, offering energy storage densities up to 200 W h L^-1. In this study, high energy density electrolytes of concentrated hydrobromic acid of up to 7.7 M are investigated. Particular polybromide ion (Br_2n+1 ^-; n = 1-3) concentrations in the electrolyte at different states of charge, their effect on the electrolytic conductivity and cell operation limits are investigated for the first time. The concentrations of individual polybromides in the electrolytes are determined by Raman spectroscopy. Tribromide (Br₃ ^-) and pentabromide (Br₅ ^-) are predominantly present in equal concentration

SUBMITTER: Kuttinger M 

PROVIDER: S-EPMC8694680 | biostudies-literature | 2021 Jan

REPOSITORIES: biostudies-literature