It would be helpful to start the article with a link to why flow batteries are amazing.
An open-source flow battery kit
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Re: An open-source flow battery kit
#72Hi! Just to say that Symantec doen not like your website! Malicious Site Blocked! Symantec Endpoint Protection blocked this website: https://dualpower.supply/
The solution is to avoid using Symantec.
Perhaps report this issue to your malware provider rather than the site owner?
Re: An open-source flow battery kit
#73Earlier quoted context omitted.
Unless you're flying a drone, you don't need to match the power and energy capabilities of lithium ion. On top of that, you don't have to match the internal resistance to match power. If you have plenty of material to absorb the heat, then you can tolerate more percentage points of loss. In particular, while lithium ion batteries can be built to sacrifice discharge rate for a bit of extra capacity, something like a 3…
I see what you are saying, in reality the right energy storage is very application dependent. The crux of my argument is that I cannot think of many applications where a commercial grade flow battery is the best choice, much less a single application where a DIY flow battery is the best choice.
> application where a DIY flow battery is the best choice
Christmas present for a battery enthusiast? :D
Re: An open-source flow battery kit
#74It's my understanding that iodine is one of those things watched very closely by the TLAs enforcing prohibition. Be careful, lest you end up unable to move about freely because this gets you on a list.
Iodine is also pretty expensive ($61/kg in 2023) so this doesn't seem scalable for that reason alone.
Re: An open-source flow battery kit
#75I cannot see how this is useful outside of being a fun student learning program. From the data it appears a battery with 1L of electrolyte provides about 18Wh of energy. Mind you this is at ~1.2V, which isn't especially useful without a boost converter. With a boost converter though you would need a low internal impedance from the battery, which I highly doubt is any good with a paper membrane (from what I understand…
Flow batteries are optimized for cost and capacity. Not weight, nor volume/energy density, nor instantaneous power delivery. In the case of some iron flow designs, add in "dirt-cheap, non-toxic materials." A pair of 55 gallon drums equals 7.4kWh, and I'm guessing a lot of us could easily find that much space in our basements. That's enough to power 300W of load 24x7 (a modern fridge is about 60W. 100W will get you re…
The actor I'm mildly paying attention to is Lockheed-Martin, who have an energy systems group that's working on flow batteries. Judging by patents, their flow battery likely uses various transition element ions that are kept in solution with any of a variety of organic ligands. The wide variety of chemistries is the attractive part, since they present many knobs to twiddle for optimization.
Re: An open-source flow battery kit
#76Earlier quoted context omitted.
Energy storage is the problem that needs a solution, e.g., storage from summer to winter.
Annual and long-tail storage are both problems that need solving, and fuel cells do look like a possible solution. But it's not clear at all what the winner will be for those applications. Even hydrogen is competitive here. IMO, more competitive than that battery chemistry on the article.
Fuel cells are a possible solution (especially if one can build a dual mode electrolyzer/fuel cell), but combined cycle power plants burning hydrogen would also work, if only at very large scale (but then economical hydrogen storage likely requires large scale).
Re: An open-source flow battery kit
#77Wow, hi all, I am Kirk, the author of this blogpost, never thought my small ARM board home server would handle this much traffic!
Currently reading through these posts, feel free to ask questions. Great to see interest.
FYI, I am quitting my postdoc job in two months to work on this full-time, which should help the rate of progress, but my main source of income will stop. We hav ea small but it will only cover a few months of full-time work.
If you want to support the project financially we have an Open Collective here: https://opencollective.com/fbrc/donate
We'd really appreciate any support you're able to give, which we'll use to push this open technology as far as we can! We are planning to start work on a much bigger stack after the kit.
Re: An open-source flow battery kit
#78It would be helpful to start the article with a link to why flow batteries are amazing.
some context: https://dualpower.supply/posts/motivation-OSHW-RFB/
Re: An open-source flow battery kit
#79I dont know anything about flow batteries, but some quick searching leads me to believe that there are two tanks of electrolytes with pumps that pump them along a membrane and then you get power across the membrane. In this small battery kit, is the idea that the battery provides enough power to both operate all its own pumps/electronics, and then output usable power? Does anyone know how much power you'd be able to…
Thanks! This kit is for R&D and educational purposes only, because of the use of positive displacement pumps (peristaltic, diaphragm, etc) instead of centrifugal pumps, it will never be able to effectively work as a battery since the pumping energy cost is high.
Once we have materials and electrolytes validated with the kit, we plan to move to a much larger cell size which will be part of a flow battery stack, which would actually function as a battery for useful storage.
Re: An open-source flow battery kit
#80It's my understanding that iodine is one of those things watched very closely by the TLAs enforcing prohibition. Be careful, lest you end up unable to move about freely because this gets you on a list.
We are planning other electrolytes beyond zinc-iodine (including iron salts), but this one happens to be practical for getting started due to widespread availability, tolerance to oxygen (avoiding requirements of purging with inert gas), and low hydrogen evolution rates (quite unlike iron-salt systems, which are practically H2 electrolyzers!).