in the last few days I have been working and published a few videos about my latest Carbonfiber and
aluminiumfoil battery cells.
Using Carbonfiber sheets and alufoil as the electrodes you can get in an alkaline electrolyte
a voltage of around 1.4 to 1.7 volts as the open circuit voltage.
Well the carbonfiber also itsself has a pretty low ohmic resistance,
only around 5 to 15 Ohms per cm distance.
So using carbonfibersmakes it easy to build such a cell, cause then only the alufoil will be consumed.
For the electrolyte you can use several different salts, like Pottassium Carbonate ( K2CO3) , Sodium Carbonate
or also called Washing Soda ( NaCO3) or also firewoodahes or coalashes in water. The latter are mostly K2O or Na0 or CaO
salts and give mixed with water also some KOH NaOH and when the CO2 from air enters, these are converted to Carbonates,
so you get free Carbonate salts.
So if you don´t have access to any Washing Soda, which could be got in any bigger supermarket and it is cheap ( around 1,50 US$ per 500 Gramms)
then you can just make a firewood and collect the ashes from it and put them into tap water to get the desired alkaline electrolyte.
Be careful not too make the concentration too high with the ashes in the water, cause then the KOH concentraion will be too high
and zje electrolyte will eat away your alufoil pretty fast and produce flammable hydrogen gas ! So be careful !
Also be very careful, that you will not get any of the ashwater or other electrolyte into your eyes as it can easily blind you !
So please wear safety goggles when you handle the electrolyte !
Well, as I did not yet have built a Joule Thief circuit, I had to put 4 cells in series to be able to light a 1 Watts LED chip reasonable well,
so you could still read a book during nighttime !
These cells runs now already since more than 48 hours and the voltage is still at around 2.55 Volts on the LED chip and the current is still
at around 4 milliamps !
Surely the inner resistance of the cells are pretty high compared to the standard NimH AA cells.
Standard NiMH cells have an inner resistance of around less than 1 Ohm.
My carbonfiber cells unfortunately have an inner resistance of around 150 to 300 Ohms,
depending on their age and some other factors.
So the power output is much smaller...
But it can be increased with different methods I will still try.
At least you can easily build with these methods your own battery cells that are able
to light up LEDs.
Here are the Videos:
Carbon fiber sheet Aluminium foil Selfmade DIY High Output batteryhttps://www.youtube.com/watch?v=KLjSH8O3cWw
1 Watt LED Light bulb testing https://www.youtube.com/watch?v=opZP6ScWgmE
Measuring ohmical resistance of different carbon fiber sheetshttps://www.youtube.com/watch?v=hWXv2zFiXXg
Despeckle Salt cell testing - carbon fiber aluminium cell https://www.youtube.com/watch?v=6_fZURgMZYc
Carbonfiber alufoil cell - building up a rollup cell https://www.youtube.com/watch?v=odDwa5-qIPI
pickup electrode for the carbon-fiber-alufoil cell and measurementshttps://www.youtube.com/watch?v=ahJQgPocsUk
3 cells in series - carbon fiber alufoil cells lighting up LED https://www.youtube.com/watch?v=ZYA48sMJZoE
4 carbon fiber alufoil cells in series running LED https://www.youtube.com/watch?v=wNsyIaT_CEA
Evening light from the 4 carbonfiber-alufoil cells https://www.youtube.com/watch?v=FokluCS-2do
24 hours runtime later - carbonfiber alufoil cells raised voltage on LED https://www.youtube.com/watch?v=ZAQuc8DeJRQ
Hope this helps.