Crossover Speciation in an Alkaline Polysulfide - Ferri/Ferrocyanide Flow Battery

作者：Ioanna Itskou, Nicola Poli, Maedeh Pahlevaninezhad, Alexander H. Quinn, Damla EROĞLU PALA, Fikile R. Brushett · 发表于：ECS Meeting Abstracts · 年份：2026 · DOI：10.1149/ma2026-01432197mtgabs · 研究领域：Chemistry、Chemical engineering、Inorganic chemistry、Materials science、Environmental chemistry

Interest in flow batteries (FBs) continues to grow due to their potential as a long-duration energy storage technology; however, further cost reductions are needed to increase economic viability. FBs with polysulfide and ferri/ferrocyanide salts as the negative and positive active species – respectively – hold promise due to their abundance, low-cost, and relatively low toxicity. 1–3 However, the performance is adversely impacted by species crossover which must be effectively managed to enable long-term operation. Prior literature suggests that crossover leads to precipitation and performance fade, but the (i) participating species, (ii) rate and extent of crossover, and (iii) generated byproducts remain largely unknown. 4,5 In this presentation, we assess crossover speciation in alkaline polysulfide – ferri/ferrocyanide FBs using a combination of electrochemical, analytical, and spectroscopic techniques. Specifically, we report experimental data collected using the same polysulfide – ferri/ferrocyanide electrolyte but three distinct approaches: (i) ex-situ mixing tests, (ii) smaller flow cells (2.55 cm 2 active area), and (iii) bigger flow cells (50 cm 2 active area). Case (i) represents potential scenarios at aggravated mixing conditions, while (ii) and (iii) represent more gradual processes at different reactor sizes. We use Scanning Electron Microscopy with Energy-Dispersive X-ray Spectroscopy (SEM-EDS) in combination with X-ray Photoelectron Spectroscopy (XPS) to charact...