I added Flux XII, a US aqueous organic RFB company, R-Flo, a Ukrainian all-iron flow battery company, and Unbound Potential, a Swiss membraneless RFB startup, to the list.
FBRC
Daniel has been making progress with cycling, we are dealing with some porous-separator specific issues (electrolyte imbalance), reminds me of my PhD, details on his blog [1]. We have a couple ideas in the works to address this—if you have an idea, please mention it in our forum here (you can reply from the forum or fediverse/Mastodon etc.)
R-Flo
I met their CEO, Andrii Bondar, years ago at IFBF in Brussels, he was nice and knowledgeable about RFB components—it was from him that I learned of “VANADion”, a Nafion-laminated porous separator. They got some UK funding recently, and here is a quick snapshot of some recent patents they got:
They also seem to be using a bigger version of the same cheapo mag-drive pumps we’re using at FBRC (HAIYI PUMP)! So, that’s nice (from Andrii’s LinkedIn post):
I wish them the best!
So now we have ESS, VoltStorage, and R.Flo all trying to do all-iron RFBs.
Lockheed-Martin
UGH. Why!?? They’re workin’ on those high-solubility iron hexacyanides for RFB applications, in case anyone was wondering [2]. In totally unrelated news: [3]
FROs, BBNs, “new” research org structures
This post got me thinking about “BBNs” - basically small private research orgs.
Some BBN-style orgs releated to electrochemical engineering:
More general energy engineering: Otherlab
Energy Vault, back at <insert anything but gravity storage> again:
Doing anything but gravity storage: lithium-ion, hydrogen, and now nuclear—I guess gravity storage doesn’t work and lithium-ion is saturated, so this is the next hype train to hitch onto?
OpenQuantum
Cool project here, seems to have similar goals as Flow Battery Research Collective:
Our goals at OpenQuantum are to:
Open-source a complete blueprint for a quantum engineering platform that is low-cost, flexible, and instructive.
Develop a novel, hands-on educational program for quantum to support the growth of a new, well-educated, technical workforce within America.
Demonstrate the power of modern open hardware paradigms in supporting both teaching and entrepreneurial communities.
Quick notes:
- Iron-air batteries, but with iridium…
New Natron factory, aqueous sodium-ion
Residential storage battery startup in Texas, Base Power.
How bipolar plates are made, from a Chinese manufacturer’s website
ESS (all-iron RFB) also delivers flow batteries to Florida utility, claims focus is above 145 kW, up to 14 h, 25-year “design life.”
NaHSO3 may help iron plating in all-iron RFBs, but not tested with cycling, in [4]:
Here, it is demonstrated that the addition of a low concentration of NaHSO3 (10 mM), as a novel additive, to an electrolyte formulation based on 0.5 M FeCl2, 3 M NaCl, and 10 mM citric acid (H3Cit) remarkably improves the electrochemical behavior of the negative half-cell. The enhanced performance can be explained as the additive guarantees a low oxygen solution content (reductant agent), promotes the plating/stripping reactions (improving the kinetics of the Fe0 deposit through the formation of a FeHSO3+ complex), and diminishes the contribution of the competitive hydrogen evolution reaction.
Flow battery recycling [5]:
Vanadium electrolytes, which account for up to 30% of system costs, can be effectively recovered through ion-exchange and chemical reduction processes, reducing dependence on primary vanadium production. Ion-exchange membranes, primarily Nafion®, are high-cost components. While recycling methods, such as chemical dissolution and recasting show promise, challenges remain in maintaining ionic selectivity and mechanical integrity. Carbon felt electrodes, which are essential for electrochemical performance, degrade over time due to fouling and oxidation and require regeneration through thermal, chemical or physical treatments.
References
Citation
@online{smith2025,
author = {Smith, Kirk Pollard},
title = {The {Flowdown} \#4},
date = {2025-02-17},
url = {https://dualpower.supply/posts/flowdown-4/},
doi = {10.59350/91yrs-e6r30},
langid = {en}
}