Rechargeable redox flow batteries: Maximum current density with electrolyte flow reactant penetration in a serpentine flow structure

TL;DR

This paper introduces a maximum current density concept for redox flow batteries with serpentine flow fields, linking electrolyte flow penetration to improved performance, validated through experiments with vanadium flow batteries.

Contribution

It presents a new maximum current density concept based on electrolyte flow penetration in serpentine flow structures, enhancing understanding of flow battery performance.

Findings

Higher current density achieved with serpentine flow design.

Validation through experimental data with vanadium flow batteries.

Flow penetration correlates with maximum current density.

Abstract

Rechargeable redox flow batteries with serpentine flow field designs have been demonstrated to deliver higher current density and power density in medium and large-scale stationary energy storage applications. Nevertheless, the fundamental mechanisms involved with improved current density in flow batteries with flow field designs have not been understood. Here we report a maximum current density concept associated with stoichiometric availability of electrolyte reactant flow penetration through the porous electrode that can be achieved in a flow battery system with a "zero-gap"serpentine flow field architecture. This concept can explain a higher current density achieved within allowing reactions of all species soluble in the electrolyte. Further validations with experimental data are confirmed by an example of a vanadium flow battery with a serpentine flow structure over carbon paper electrode.