Thank you for this, as somebody with almost no background in chemistry, I can now appreciate just a bit more the complexity that goes into battery development. Where does one learn about this?
I’ve been sending these guys $10 a month for a while now. Thir test cell is chemistry agnostic, and I think they have tried several ferrous solutions. The membrane issue is not that big of a deal it seems if you aren’t trying to miniaturize the device- separator material used in car batteries can be used to good effect and it’s easy to replace if needed.
I love this kind of work. They had an ambitious timeline and the last entry was at the beginning of this year -- do you have a sense if they are still going strong?
I’m really not sure. Things like this often run out of steam, get picked up later, etc as the interest and the lives of the people change, new people come, old ones move on. We will see.
I would assume it's a typo on GWh. It seems probable to me that the battery can supply/absorb 1.2GW on a millisecond response time, so it would be able to fully charge/discharge in a little less than 2hours, supplying/absorbing 1.2GW with 2.1GWh total capacity.
The advantage of vanadium batteries, as I understand it, is that leakage does not corrupt the system. The vanadium gets converted to the right chemical species on either side.
Flow batteries specifically are liquid, or more accurately fluid, there can be gas flow batteries, where the chemical sub-products are pumped in and out of the cells.
They tend to be large utility scale things that look like a chemical plant, correction, are a chemical plant with electrical storage as the product.
Liquid electrolyte batteries have been a thing from when batteries have been invented. But not much work has been done to really scale it up.
Ferrocyanide is not dangerous. Sodium ferrocyanide is used as an anti-caking agent in table salt. It's considered safe for this use in both the US and the EU, e.g.:
Exactly. Table salt has an LD50 of 0.5-1g/kg, 1.5-3x more toxic. I weigh ~85kg, I'd have to eat about 46 cubic centimeters of potassium ferrocyanide (on the conservative side) to consume an LD50 worth.
If you're talking about the chemicals in batteries we have today, the LD50 is probably way lower for most of them. If we're talking about batteries for consumer electronics, you'd have to eat (density wise) multiple batteries worth of potassium ferrocyanide to hit LD50.
> When using ferrocyanide, also consider that while this salt is relatively safe in its unaltered state, subjecting it to electrochemical abuse WILL generate free cyanide and it’s likely to pose a significant danger to you and others. For this reason, I would recommend to stay away from testing ferrocyanides in symmetric systems entirely, unless you are a trained professional and professionally well equipped to handle both the potential operational hazards and wastes generated from its decomposition products.
After all, people painted the walls and enhanced their gas with cyanide in large quantities for years before even realizing it had to be carefully handled so they are basically the same risk in the typical mind.
The problem is free cyanide is extraordinarily dangerous in the air and you'd likely kill a lot of people before someone realized what was going on with the battery, not just that people eat batteries. Even lithium batteries honestly get pretty close to not being worth the risk for consumers, cyanide is still a bit of a step after that yet.
Somewhat true, but consumers are buying vast quantities of lithium batteries and carrying them in their pockets. Those things are eager to catch fire and emit hydrofluoric acid.
You can have safe battery chemistry or useful battery chemistry. (Not an expert, open to correction.)
Well they sell that liquid explosive terrorists use to make molotov cocktail firebombs, at every fuel station without particular volume limits at all. It's also sufficiently toxic that care is taken at salespoint to limit customer exposure to the vapours.
(these things are "all relative, if the value, measured in "convenience to the customer", is high enough,
ways will be found to permit sale)
The public is not going to buy a flow battery anyway.
Or perhaps they will, but only when public is taken in the context as in public utility or public city. But individuals are not going to buy a flow battery, it is a chemical plant.
If we're going to do chemical-plant scale utility batteries, why not just lead-acid? It's well understood, simple, and the ingredients are cheap. Yes lead is toxic but it's easily contained and recyclable.
I think the very fact that PbS and for that matter NiFe have been around for decades and aren't widely deployed for utility scale probably counts against it. I suspect the answer may be that weight matters enough just in the cost of delivery to the site. Where utility scale storage is being deployed it's lithium; may switch to sodium as that crosses over in cost.
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