The potential of non-aqueous redox flow batteries as fast-charging capable energy storage solutions: demonstration with an iron–chromium acetylacetonate chemistry

Abstract

We report a fast-charging iron–chromium non-aqueous redox flow battery that combines the fast kinetics of the single iron(iii) acetylacetonate redox couple on the positive side with the fastest of the chromium(iii) acetylacetonate redox couple on the negative side.

A high-performance all-iron non-aqueous redox flow battery

“…The linear relationship between the peak current and the square root of the scan rates (Fig. 2c and d for NARFBs [16,22]. The solubility of both active species in 0.5 M TEATFSI/MeCN was measured by UV-Vis absorption spectra (Figs.…”

“…3a and b) exhibits rather stable cycling. The average CE, voltage efficiency (VE), and energy efficiency (EE) are 98.7%, 84.5%, and 83.4%, respectively, over 100 cycles, which are much higher than most non-aqueous systems [22,26]. The average discharge capacity is 1.50 Ah L -1 .…”

Investigation of Cubic Fe4M4 Frameworks for Application in Nonaqueous Energy Storage

“…We hypothesize that this molecular rearrangement results in the reduction in k 0 for this event. Still, the kinetics for all four of the charge‐transfer events in Fe 4 Mo 4 O 16 are notably fast, a property which has positive implications on both the energy efficiency and power density of an RFB system . For the tungstate analogue, Fe 4 W 4 O 16 , the electron‐transfer rates are overall slower than those observed for Fe 4 Mo 4 O 16 , on the order of 10 −2− 10 −3 (Table ).…”

Review of the Development of First‐Generation Redox Flow Batteries: Iron‐Chromium System

“…Bamgbopa et al reported the first attempt at non-aqueous ICRFB containing Cr(acac) 3 and Fe(acac) 3 active species with TEABF 4 as the supporting electrolyte in 16 : 84 (vol %) 1,3dioxolane/acetonitrile. [43] The redox reactions are well-positioned to enable fast charging at up to 1.8 V, which is above the OCV (1.2 V). Further, the hydrogen evolution issue was not observed in this non-aqueous ICRFB.…”