Carbonfiber Alufoil selfmade DIY battery with NACO3 or Ashwater electrolyte

[b_rads]

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Although the open circuit voltage with Washing Soda - Water electrolyte  is then only around 1.15 to 1.20 Volts,
the shortcircuit current, when the cell is new, also begins over 100 milliamps, from a water glas type sized cell.
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Regards, Stefan.

What is the ratio of your Washing Soda mix.  The SS Scrubbers are great since they have so much surface area to work with.  I would also think that the Aluminum Foil should be crumpled up into a nice fairly dense electrode, again to increase surface area.  Even with a lot of surface area, these cells tend to polorize after a while limiting their long term output.  Sometimes, just draining of the solution and rinsing the electrodes will clean up the cell and make it function much longer.  The electrolyte can even be reused.

Recently reproduced Lidmotor's SS and Epsom Salt Rechargeable cell and I am getting 7 to 11 days on a blinking oscillator circuit before needing to recharge the cell.

Please inform on the Washing Soda mix so I can have a baseline to work from.  Much appreciate all the sharing with this build.

Brad S

[Magluvin]

One thing about stacking the cells is for example....

If we have 2 individual square flat cells, sitting side by side, not touching each other, and they both produced similar potential and currents, when paralleled, the current capability should be 2 times what 1 cell produces. But if we stack the 2 cells, more surface area, the back side of 1 cell to the face of another will account for more current capability using the same 2 cells.  Rolling them is probably the best as there will only be some of the rolled cell surface not being used, the outer side of the roll.
But if stacking many cells, the top and bottom not being used, the more you have in the stack, the less the top and bottom surface area not being used will matter, like the rolled version.

I wonder if like  the first batteries, the piles were squeezed down, if this would do better with pressure being applied like the screw on the top of the pile?
Maybe fiberglass cloth instead of paper towels would be better if applying lots of pressure. To reduce the possibility of a short in the cell. Just an idea.

Mags

[hartiberlin]

Okay, here are some quick answers.
The cells are still running contineously and still ighting the LED although the brightness have decreased.

The cells also dried out a bit and I will tommorrow water them again and see, if the brightness of the LED gains this way again.

Well, surface area is still the most valuable in these cells and could be made big.

Well you could also use a silver coated copper wire to reduce the resistance of the carbon fiber mesh
but this then has to be folded a few times around the carbonfiber so it will pickup lots of current from the
carbonfiber strands and probably the copper beneath the silver will begin to decompose
after a while.
Also you can add lampblack to the carbonfiber electrodes and thus increase very much the surface area and the oxygen
input capabilities. Remember it is an aircell, where the O2 is converter into ions at the carbonfiber electrode.

Also stainless steel mesh plates could be added to the carbonfiber together with lampblack or graphite powder
grinded into the mesh holes of the stainless steel mesh. This would give the most powerful cell,
as this principle is also used in NiMH cells.

For price reasons you can also only use stainless steel mesh with grinded lampblack or graphite powder into it as one electrode
and as the other electrode aluminiumfoil.

As the electrode you can use 3 to 5 teaspons of NaCO3 or K2CO3 into 100 milliliters of destilled water.

If you can´t get these electrolyte salts you can also use ashwater from a firewood, but it has to be the right concentration
as there is much KOH in it, which will justz decompose the alufoil on its own.

Use a straw to blow your used breath (CO2) into the ashwater ( Wear safety goggles as the KOH-water can blind you !)
so you convert the KOH with CO2 into K2CO3 and it will not eat anymore so fast your alufoil away !
Easy trick to convert KOH into K2CO3 inside the solution.

You can of course also use other CO2 sources like selfmade gazed water  bottle units..

Be always sure to wear eye protection as the KOH can easily blind you if you get it into your eyes !


Hope this helps.


Regards, Stefan.

P.S: The Nickel Zink Accumulator cells could also be selfmade very nicely  like this:

https://www.youtube.com/watch?v=P2-It0zdcKM

These have so much more power !
Aslmost 2 amps shortcircuit current.

You can also galvanically coat carbonfiber sheets with Nickel metal , so this wll be also very interesting to try !

[markdansie]

Nice work I am enjoying this thread
Batteries are so much fun

Kind Regards