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Testing the ZnBr2 cells/chemistry zinc bromide
#11
Results so far for the new improved cell design:
Below 3.20v they will not take any charge, above 3.60v you will oxidize the zinc crystals.
Resulting in a to high resistance to give or take any power, meaning deplete them to 0v and start all over again.
Deplete them to 0v to start them fresh, give them 3 days and the zinc will dissolve back into the solution.
Going to test this a couple of times more for there max charge.

When they are done with discharge they will go immediately back to 1.77v from 1.82v.
(Round two: 1.70v from 1.77v will give you ~80mah per 10cc.)
Every 10cc of 1.75 M solution will give you ~100mah.
No matter how big or small the cell is. (In my test cases 10cc 30cc 50cc and 100cc.)
All the cells have a id of 54 millimeters.
100mah per 10cc.
What is also interesting, the charge and discharge rate:
150-200mah charge, 100-150mah discharge.
All those numbers are keep on coming back!!!

Going to test with different electrodes:
Graphite foil, graphite rods, electrodes made of copper and carbon filled paper and ferrite rods.
Width and length.
Try to improve the electron flow.

With those numbers we can theoretically calculate what we need for a 12kwh storage.
28 jerry (25 liters) cans filled with 1.75 M solution, 2 M is almost not possible, or boil it of.
8 kilograms per jerrycan and 20 liters of distilled water.
Meaning we need 224 kilograms of ZnBr2 and 560 liters of distilled water.
You can put 12 jerry cans on one square meter.

The cheapest ZnBr2 supplier out of 15 inquiries was incl shipment ex vat or local tax (IF you are able to get this into your country) 1100 euro's, per 100 kilograms.
Drum with 200 liters of distilled water: ex shipping: 100 euro.
If we would go to 1.6 M solution, the costs for 10-11kwh storage, would be 300 for the water and 2200 for the ZnBr2
In lifepo4 same storage would be:3700e ex vat.
The ZnBr2 needs also a full bms! for 28 to 30 cells per string for 48v to 50v

Conclusion: it works, it is cheaper, BUT you will have to deal with a very VERY low c rate.
You will need a lot of room, create your own bms, health hazard, ect

Protect yourself from metal fever (zinc oxide is also absorbed thru the skin, make absolutely NO mistake about that!!!)
Metal fever is absolutely no joke, yes i was young and stupid once.
After a cell is charged, there is a cloud of bromine, this is a very poisonous liquid, evaporates very quick even at 0 celsius temps, don't let it escape, keep it under water, it is healthier to get copd from smoking.
Bromine will attack and permanently damage your organs, from nose, eyes and mouth to the other end.
Unless you had the proper education and have the right stuff for this, don't go here.

I went further than a lot of published papers and experiments, at least i have some hard numbers!
Vacation well spent, i will not proceed to build a ess out of ZnBr2 cells.
Holy grail? sorry no, too much fuss to get the proper materials, building, controlling and maintaining the cell's.
Room for error is also to small.

Thanks for reading, tips, hints and thoughts that were shared.
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