Getting amps from small selfmade DIY Zinc Air cells, amazing !

[hartiberlin]

Hi. I have registered in this forum looking for a independet prize for a real world-scale new idea for solvering the world energy demand...I have one of such kind of ideas, can you tell me how can I apply for the prize, please?. Thank you so much. Dr. Luis Juanicó, argentinean researcher in renewables.

Hi,
have a look at this:

http://www.overunity.com/index.php?topic=5707.0

Do you have a selfrunning system that needs no batteries and puts out more than 1 Watts ?

Thanks.

Regards, Stefan.

[hartiberlin]

Here are a few answers from user Anders from the Sweish forum,
which he emailed me and said, it is okay to post it here:

Hi Stefan!

We got the Teflon for free from Dupont in Norway, they was thrilled to support such a potentialy interesting project, and 1 L cost only 250 SEK + VAT.
I belive firmly it would be best for all if you could order directly from an office in Germany, our supply is limited for own use.
Also notice that Dupont for commersial use requires a license agreement, therfore state the nature of the project beeing small scale testing of batteries.
If You still will not succeed getting any deliveries (from Germany), perhaps try with the office in Norway, ask for John Jansen at phone +47 38084100 (perhaps old number?), or try Dupont in Sweden, phone: +46 8591194 39.

Notice that perhaps (?) the number 30B my have been changed to TE 3885 ?!
""Teflon® PTFE 30B fluoropolymer resin is a negatively
charged, hydrophobic colloid, containing
approximately 60% (by total weight) of 0.05 to
0.5 mikrometer polytetrafluoroethylene (PTFE) resin
particles suspended in water. Seen as a milky white
liquid, it also contains approximately 8% (by weight
of PTFE) of a nonionic wetting agent and stabilizer.""

http://www2.dupont.com/Teflon_Industrial/en_US/products/product_by_name/teflon_ptfe/aqueous.html

http://www2.dupont.com/Teflon_Industrial/en_US/assets/downloads/k15764.pdf

Thanks for the graphite paper offer, but no thanks, pretty much everything is best with the stainless mesh, the price is almost nothing and the cathode becomes ridgit/more solid and very good conducting electricity. I do reecomend You using it!
http://www.sintab.se/

Before I forget it, for the cathode to work over one our it needs a "cellguard" film atatched to the wet electolyte side. I have not yet testing this myself since I have bought commersial cathodes from Electric Fuel (to speed up the prototype making). Probably later I wiil do a test with also a cellguard attatched to the cathode.

http://www.celgard.com/default.asp
http://www.celgard.com/products/specialty-membranes.asp

Sorry if I cant keep up with all Your questions for the moment, belive it or not, but all in a sudden the acitivity around this zinc air battery project just explodes...! So much to write and study that I wish I had two brains....

My problems besides trying to save the world (...) with good EV batteries, is that I so many other ideas I would like to experiment with, a favorite is a solar cell made with an ink jet writer onto transperant plastic film (for OH), and spray different layers of nano coal and nano copper oxide, also have solutions on wind turbines and, well You guessed right -a free energy device (a magnet generator). But please, I am so limited in strenght and resources I hardly keep up whith this zinc project!

Regards
Anders

[hartiberlin]

> Hi Anders,
> many thanks for these infos.
>
> Could this be posted in my forum or is this info
> just for me ?
>
> What is the Teflon exactly doing ?
>
> Does it just only support more oxygen from
> the air going into the graphite (charcoal )
>
> What happens, if you don´t use the Teflon ?
> Is the current then much lower ?
> How much lower ?
>
> Also what about the Maganese Nitrate ?
> Is this still used in your cell ?
>
> I will be soon trying KMNO4, and I hope I don´t blow myself up.
>
> Well, the graphite paper is very easy to make with a cheap
> acrylic binder and this graphite electrode then conducts
> very well, so no stainless steel needed, which saves money...
>
> Wherefore do you need this cellgard ?
> Is this there for the recharge capabilities
> or can´t you just otherwise use a gel like
> superabsorbers (polyacryl salts)to keep the KOH solution inside such a gel ?
>
> Many thanks.
>
> Regards, Stefan.


Hi Stefan!
Please feel free to copy mail corespondence (my spelling sucks though...)!

The Teflon permits oxygen to enter the micro pourus space in the (well packed) activated carbon, through high surface tention repelling the liquid electrolyte (KOH/H2O) and creating path ways for the air to travel inside the cathode, otherwise only the outer atom layer of the cathode would be active, followed by a very low current density (mA).
There are other concepts dealing with the air flow problem; some use a lose (fluffy and space consuming) carbon powder without any Teflon, but this cause a very high inner resistance with a high voltage drop, which also make them power weak.
See:
http://elbil.forum24.se/elbil-about844-0-asc-80.html
http://www.tedilo.de/advanced_search_result.php?keywords=zink&x=0&y=0

Notice that when making a cathode one must use fine activated carbon powder, not just ordinary coal (from the woodstove...). What makes catalysies to work is the plentyfull very tiny pits on the carbon surface -its all about having a huge amount of active surface for the oxygen to interact and become into OH with the electrolyte (actualy the water). It will work with ordinary coal powder as well, but it will give of a very low current.
And the adsorbed Silver or MnNO3 are mainly there to raise the cell voltage. It works fine also without the adsorbed "voltage doping" substance (Silver), but the cell voltage will be lower when discharging/draining current.
The cell seen on Youtube have Silver in it, wich give a slight higher voltage than MnNO3.
It is also more easy to do the adsorbing process with Silver, since the MnNO3 requires a baking process during several days...

The cellguard fabric prevents poisening zincate ions (negative charged zinc) to enter the cathode which will reduce the catalytic activity and thereby stop the cell function. The zincate ions are temporary semi product in the process of forming ZnO from Zn.
So a cell without cellguard will function only a rellative short while (hours).
I gues it would be possible to fix this zincate problem with also other technics, like a internal galvanic polarity charge /tention/voltage that prevents the negative ions from travling from the zinc anode to the cathode...(?)
I gues a gel would also (at least partly) stop the zincate ions, it needs to be tested!

And by the way, the electrolyte are not consumed during discharge, it has the same overall concentration all the time. In the cathode oxygen are binded with hydrogen to OH (negative charged), and releases the hydrogen back to the electrolyte at the zinc anode where zinc becomes into ZnO. -A closed lope.

Regards
Anders

[jadaro2600]

Due to a lack of multilingual abilities, as / would it be possible to get an English DIY how-to for this type of cell?  Can someone post some instructions as well as an good explanation of what is going on in the same instructions.

I've read the basic information, however, there are still undetermined factors, I think.

[neutrino]

How to make an air cathode without Teflon. -a sintered electrode using a slight over air pressure:
http://en.wikipedia.org/wiki/Gas_diffusion_electrode

Wikipedia about zinc and aluminium air battery. Notice that zinc gives of 2 electrones for every used zinc atom, while the aluminium atom gives of 3 , and at the same time beeing more then twice as light, giving theoretical 6000 Wh/kg...
http://en.wikipedia.org/wiki/Zinc-air_battery
http://en.wikipedia.org/wiki/Aluminium_battery