Starch-mediated colloidal chemistry for highly reversible zinc-based polyiodide redox flow batteries.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 38714710.
- Also identified by DOI 10.1038/s41467-024-48263-8 and PMC identifier 11076626.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Aqueous Zn-I flow batteries utilizing low-cost porous membranes are promising candidates for high-power-density large-scale energy storage. However, capacity loss and low Coulombic efficiency resulting from polyiodide cross-over hinder the grid-level battery performance. Here, we develop colloidal chemistry for iodine-starch catholytes, endowing enlarged-sized active materials by strong chemisorption-induced colloidal aggregation. The size-sieving effect effectively suppresses polyiodide cross-over, enabling the utilization of porous membranes with high ionic conductivity. The developed flow battery achieves a high-power density of 42 mW cm<sup>-2</sup> at 37.5 mA cm<sup>-2</sup> with a Coulombic efficiency of over 98% and prolonged cycling for 200 cycles at 32.4 Ah L<sup>-1</sup><sub>posolyte</sub> (50% state of charge), even at 50 °C. Furthermore, the scaled-up flow battery module integrating with photovoltaic packs demonstrates practical renewable energy storage capabilities. Cost analysis reveals a 14.3 times reduction in the installed cost due to the applicability of cheap porous membranes, indicating its potential competitiveness for grid energy storage.