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An open-source flow battery kit

dualpower.supply

1–10 of 111 posts

Re: An open-source flow battery kit

#2
I 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 it already isn't great for flow batteries).

Meanwhile a pair of 18650 lithium ion batteries can be had for $5 and can provide 24Wh at a very usable 7V with no power conditioning or a range of voltages with more than enough ability to source current. And it is a fraction the size, weight, and complexity.

I don't mean to tear apart the project, perhaps there is a key detail I am missing, but I just don't see what this is trying to do outside being a learning experience for students.

Re: An open-source flow battery kit

#3

I 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…

Typically if you want to DIY something you first start with the smallest prototype possible and work your way up from there.

This demo cell isn't super interesting on its own but to validate the chemistry it's super helpful. Once you got that done you'd then work on a stack of cells, say 10 or 20 or 40 to get up to normal system voltages.

Once you have that working it's just a matter of making the tank as big as you want for your storage. Provided the initial chemistry is reasonable you could probably use a pair of IBC totes and really go somewhere.

Re: An open-source flow battery kit

#4

I 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…

"For some scientists doing flow battery experiments in their respective homes/apartments, we’ve got some solid preliminary results"

Obviously it's a research project not a commercial product. What do you expect?

Re: An open-source flow battery kit

#5

I 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…

Typically if you want to DIY something you first start with the smallest prototype possible and work your way up from there. This demo cell isn't super interesting on its own but to validate the chemistry it's super helpful. Once you got that done you'd then work on a stack of cells, say 10 or 20 or 40 to get up to normal system voltages. Once you have that working it's just a matter of making the tank as big as you…

Yeah! The thing about flow batteries is that if we manage to find good chemistries, they have the potential to be very cheap energy storage compared to ordinary batteries. High energy, low power, low cost.

Ie the small electrodes cost something but the big bag of fluid might be cheap.

Say, vitamin- like substances consisting of extremely common elements like hydrogen, oxygen, nitrogen, carbon etc could be used to store energy in a flow battery. Even with quite low performance, they could be very cheap compared to things like cobalt, nickel, manganese or lithium.

Or what about quinones? And sodium, sulphur, sodium are cheap too. There are a lot of very cheap chemistries that could be explored!

Re: An open-source flow battery kit

#6

I 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…

Personally I would find it useful for applications where there needs to be little to no self-discharge and fire safety - like a remote shed with some kind of sensor.

Re: An open-source flow battery kit

#7

I 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…

Not a battery expert, but this seems the right ballpark for useful batteries.

Back of envelope stuff:

1liter for 18Wh.

1k liter 18KWh (this is an average hot tub).

10k litre for 180Kwh. This is a ~$1000 farming tank.

~100KWh lithium batteries are around the $20-30k. (Used Tesla pack for reference)

Quick google shows flow electrolyte in the neighbourhood of $100 per KWh. Or $10k for a ~100KWh battery.

All this is nothing definitive, but it’s not showing any 10x or 100x differences that would rule out an interesting idea.

Re: An open-source flow battery kit

#8
Lots of software started this way: as a toy, a proof-of-concept, a learning opportunity for the programmers. I really hope that they find interested people who join their experiments, and build something awesome and open together.

Re: An open-source flow battery kit

#9

I 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…

You are missing that this is just some salts dissolved in water, while the 18650 is a highly complex device.

How much does it cost to store 10m^3 of water? And hos much does it cost to store the same energy in 18650 batteries?

Also, the internal resistance depends entirely on how many cells you have. But a practical battery wouldn't use paper.

Re: An open-source flow battery kit

#10

I 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…

This is awesome!

Obviously we’d need a real ion exchange membrane and put 40 of them in series, but it looks pretty scalable even in its present form. This looks very practical to me, once a few more years of tinkering is done.

I’d love to have more information about electrode fluid cost, life and reconditioning/reprocessing, as well as power densities for membrane area.

I’d love to be able to add capacity just by adding tanks and electrode fluid! For microgrids like ours, this is a longstanding goal.

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