100kwh-hunter
Active member
- Joined
- Mar 2, 2019
- Messages
- 1,355
Hi ya all.
This project started several weeks ago and i have good hoops for a good ending, if no good ending: bad luck, waste of money but a LOT of fun.
A forum member brought this to our attention, and i decided to experiment further with it:
https://secondlifestorage.com/showthread.php?tid=8557
In short
Those cells can not give a high c number, but can pack a lot of power
There are 2 or three claims of 2c, and 100 claims under the 0.5c
There are theories (i found one real test paper)of mixing a chemical with it, that could bump up the c, but the shelf life will be drastically reduced.
For example: with iron oxide it would be 1c but 1500 cycles.
Those cells could have a cycle life well over 10.000 if we stick only on ZnBr.
The first tests where depleting it to 0v and really overcharging, it seems it did no harm.
I will create a separate thread for thisand put a link to the test results over here.
Cause this is a lot of material....
My cell surface is 35cm2 at a discharge/charge rate of 20-40mah per cm2.
Would imply: 0.7-1.4ah but for 20 hours long.
What my cellstheoretically could store =~14to 28A????? at 1.82v
I think this is the best way to build a proper testing cell for some chemistries, in my case the znbr2 cell, before i take it further for a ess:lets build and test.
Test results will be in a separate thread.
The beginnings of the build are in the link mentioned above
The used materials can withstand a broad variety of chemicals.
This is the cheapest way:cutting up a jerry can, softening the hdpe in the oven at a preheated oven at ~100C molding it warm into a jig, soldering the case close.
What is very important, to get your cell case closed.
Before you put in oasis, iron the edges flat.
One wrong and one the proper way in a picture:
You really want to see the edges of the hdpe sticking to the baking paper.
Don't move your iron, let it float flat, incase your iron has those steam holes in it.
You really want to have a flat level and strait surface on your cell walls, the melted and thus extra stuff we will get back to that.
But make sure its flat.....
DO THIS IN A VENTILATED AREA!!!!
Work in pairs and a flat bottom weight, meaning: work on one let the other cool down under weight.
When one is "flattened out" the other one is cool and rigid enough to put aside.
Prepare/cut your carbon foil,your graphite foil and oasis(rockwool can be a better option btw)
Don't mind if the oasis is oversized or thicker, it's better!
Iron in total 4 pieces carbon foil with one piece of graphite foil together, onepiece at a time! use your baking paper so you wont DUCK up your (wifes) iron.
180 to 190 celsius is advised, it will take a couple of seconds to let the heat sink in to the hdpe, you will feel after a couple of times.
DO THIS IN A VENTILATED AREA!!!!
As last you iron the graphite foil on it
Made no pictures sorry, forgot.
Now remember i told you to flatten out the cases? cut one side the inner rim out, so you will create a bevel base:
Press this in your oversized oasis:
Cut to size with a good long and thin knife, like a fish knife.
Now thethickerpart:
Press it well into your cell casing, with help of a piece of wood, press hard but you don't have to stand on it.
Cut the excess materials, that's why no stanley knife but a fish knife, not to thin and sharp.
Dont matter if there is one mm still sticking out. that is better than 1 mm to little!!!
Oke get your sheets of heat welded carbon and graphite foil.
Place one at a side of your cell case, baking paper over it and the iron.
It should look like this, that's why the first step was to flatten out your case!!!!
DUCK up two or five...but then you have the feeling!
Oke now we can go difficult or easy...it is for testing lets do it the easy way.
Get some alu tape(conductive type!) and put your wires on.
When charging, the first or the 10.000st time, positive is always down and negative always up! This is the influence of gravity on the ZnBr cell
WARNING WARNING WARNING
THIS IS NO JOKE, USE IN A WELL VENTILATED AREA.
If your nose is getting irritated just like with regular acid, go outside, breath in via mouth and out via nose.
Cover all with lids and vent better before proceed!
Measure every thing as best as you can, a "normal" kitchen whitening scale won't suffice at those small amounts.
100 ml distilled or demineralized water and add 40 gr of znbr2.
Stir every half hour for three hours, don't mind the heat, it is not much.
Yes it is still not clear, some manufacturers throw some waste into it, no panic, just let it settle 24 hours, it will sink down.
After 24 hours than you will have a transcuralendfluid clear as water. dont let the sediment come back into your solution.
After just 12 hours i got this:
You will see some sediment on the glass walls, i scratch some away with the spatula.
Clear as water:
The sediment is some cheap undissolvable salt, that has nothing to do with the zn or br.
Bromine salt is gainedfrom the oceans waters, i thought, so i suspect its a salt or mineral residue that is really hard to get out.
Oke drill two holes in your casings, don't go to deep....only casing, you could prep this before you put in the oasis.
Put your two syringes into the holes, fill one syringe with your electrolyte(znbr2 solution)
And let the law of communicating vessels do its job!
Take time! can take up to 24 hour before complete full...
When they are full
You close the holes with a piece of hdpe, let it melt into the hole and make sure its really closed.
As a test, you could squeeze softly in the cell, if any dripping is occuring melt it to close it.
Its a feeling when both surface areas are connected, your solder iron will start sliding.
Hook it up to your charger and let the initial charge begin. My hand is in front of the display so you can see i am still testing cell 1 and 2 with leds.
Again:When charging, the first or the 10.000st time, positive is always down andnegative always up! This is the influence of gravity on the ZnBrcell
Because this is a global site:I use the metric system, to avoid (calculation) mistakes from my side.
I think this covers everything of my second attempt to make test cells.
I also don't think the basic design will change much, only one ore two double in height and one or two in surface area.
By this time i run out of my ZnBr2, depending on the numbers of the experiments i will A: buy nothing more or B:in doubt buy 500 grams or C: convinced: buy 25 kilo(forum member will benefit if they want to try ofcourse!)
Best
This project started several weeks ago and i have good hoops for a good ending, if no good ending: bad luck, waste of money but a LOT of fun.
A forum member brought this to our attention, and i decided to experiment further with it:
https://secondlifestorage.com/showthread.php?tid=8557
In short
Those cells can not give a high c number, but can pack a lot of power
There are 2 or three claims of 2c, and 100 claims under the 0.5c
There are theories (i found one real test paper)of mixing a chemical with it, that could bump up the c, but the shelf life will be drastically reduced.
For example: with iron oxide it would be 1c but 1500 cycles.
Those cells could have a cycle life well over 10.000 if we stick only on ZnBr.
The first tests where depleting it to 0v and really overcharging, it seems it did no harm.
I will create a separate thread for thisand put a link to the test results over here.
Cause this is a lot of material....
My cell surface is 35cm2 at a discharge/charge rate of 20-40mah per cm2.
Would imply: 0.7-1.4ah but for 20 hours long.
What my cellstheoretically could store =~14to 28A????? at 1.82v
I think this is the best way to build a proper testing cell for some chemistries, in my case the znbr2 cell, before i take it further for a ess:lets build and test.
Test results will be in a separate thread.
The beginnings of the build are in the link mentioned above
The used materials can withstand a broad variety of chemicals.
This is the cheapest way:cutting up a jerry can, softening the hdpe in the oven at a preheated oven at ~100C molding it warm into a jig, soldering the case close.
What is very important, to get your cell case closed.
Before you put in oasis, iron the edges flat.
One wrong and one the proper way in a picture:
You really want to see the edges of the hdpe sticking to the baking paper.
Don't move your iron, let it float flat, incase your iron has those steam holes in it.
You really want to have a flat level and strait surface on your cell walls, the melted and thus extra stuff we will get back to that.
But make sure its flat.....
DO THIS IN A VENTILATED AREA!!!!
Work in pairs and a flat bottom weight, meaning: work on one let the other cool down under weight.
When one is "flattened out" the other one is cool and rigid enough to put aside.
Prepare/cut your carbon foil,your graphite foil and oasis(rockwool can be a better option btw)
Don't mind if the oasis is oversized or thicker, it's better!
Iron in total 4 pieces carbon foil with one piece of graphite foil together, onepiece at a time! use your baking paper so you wont DUCK up your (wifes) iron.
180 to 190 celsius is advised, it will take a couple of seconds to let the heat sink in to the hdpe, you will feel after a couple of times.
DO THIS IN A VENTILATED AREA!!!!
As last you iron the graphite foil on it
Made no pictures sorry, forgot.
Now remember i told you to flatten out the cases? cut one side the inner rim out, so you will create a bevel base:
Press this in your oversized oasis:
Cut to size with a good long and thin knife, like a fish knife.
Now thethickerpart:
Press it well into your cell casing, with help of a piece of wood, press hard but you don't have to stand on it.
Cut the excess materials, that's why no stanley knife but a fish knife, not to thin and sharp.
Dont matter if there is one mm still sticking out. that is better than 1 mm to little!!!
Oke get your sheets of heat welded carbon and graphite foil.
Place one at a side of your cell case, baking paper over it and the iron.
It should look like this, that's why the first step was to flatten out your case!!!!
DUCK up two or five...but then you have the feeling!
Oke now we can go difficult or easy...it is for testing lets do it the easy way.
Get some alu tape(conductive type!) and put your wires on.
When charging, the first or the 10.000st time, positive is always down and negative always up! This is the influence of gravity on the ZnBr cell
WARNING WARNING WARNING
THIS IS NO JOKE, USE IN A WELL VENTILATED AREA.
If your nose is getting irritated just like with regular acid, go outside, breath in via mouth and out via nose.
Cover all with lids and vent better before proceed!
Measure every thing as best as you can, a "normal" kitchen whitening scale won't suffice at those small amounts.
100 ml distilled or demineralized water and add 40 gr of znbr2.
Stir every half hour for three hours, don't mind the heat, it is not much.
Yes it is still not clear, some manufacturers throw some waste into it, no panic, just let it settle 24 hours, it will sink down.
After 24 hours than you will have a transcuralendfluid clear as water. dont let the sediment come back into your solution.
After just 12 hours i got this:
You will see some sediment on the glass walls, i scratch some away with the spatula.
Clear as water:
The sediment is some cheap undissolvable salt, that has nothing to do with the zn or br.
Bromine salt is gainedfrom the oceans waters, i thought, so i suspect its a salt or mineral residue that is really hard to get out.
Oke drill two holes in your casings, don't go to deep....only casing, you could prep this before you put in the oasis.
Put your two syringes into the holes, fill one syringe with your electrolyte(znbr2 solution)
And let the law of communicating vessels do its job!
Take time! can take up to 24 hour before complete full...
When they are full
You close the holes with a piece of hdpe, let it melt into the hole and make sure its really closed.
As a test, you could squeeze softly in the cell, if any dripping is occuring melt it to close it.
Its a feeling when both surface areas are connected, your solder iron will start sliding.
Hook it up to your charger and let the initial charge begin. My hand is in front of the display so you can see i am still testing cell 1 and 2 with leds.
Again:When charging, the first or the 10.000st time, positive is always down andnegative always up! This is the influence of gravity on the ZnBrcell
Because this is a global site:I use the metric system, to avoid (calculation) mistakes from my side.
I think this covers everything of my second attempt to make test cells.
I also don't think the basic design will change much, only one ore two double in height and one or two in surface area.
By this time i run out of my ZnBr2, depending on the numbers of the experiments i will A: buy nothing more or B:in doubt buy 500 grams or C: convinced: buy 25 kilo(forum member will benefit if they want to try ofcourse!)
Best