Hydrogen evolution reaction in flow battery

Is parasitic hydrogen evolution a problem in flow batteries?

Nevertheless, parasitic hydrogen evolution at the negative electrode remains an issue for the long-term operation of flow batteries relying on acidic electrolyte solutions such as iron-chromium (E 0 of Cr 2+ /Cr 3+ = −0.41 V) 16 – 18 and all-vanadium (E 0 of V 2+ /V 3+ = −0.26 V) 19 – 21 types.

Does carbon fiber affect hydrogen evolution in redox flow batteries?

Carbon fiber-based fabrics such as felts, cloths or papers are porous electrode materials that are widely used in redox flow batteries. This study investigates the effect of the carbon fiber properties on hydrogen evolution at the negative electrode, which occurs as an important side reaction in redox flow batteries employing acidic electrolytes.

How does parasitic hydrogen evolution affect cell resistance?

In the case of operation at high states of charge (SoC), parasitic hydrogen evolution exacerbates the well-known electrolyte imbalance, which is caused by solvent crossover and emerges during long-term cycling. 25, 26 This effect leads to an incremental capacity loss during subsequent charge-discharge cycles and an increase in cell resistance.