Test of aluplate<->sand-graphite-tablesalt battery cell

[hartiberlin]

Hi All,
I did today again a few test, cause I wanted to see, if the
crystall battery effect of M. Reid and John Hutchinson could
be made with an aluminium plate and a mix of SIO2 ( sand)
and graphite powder.

Therefore I took an aluplate about 2 mm thickness and about 25 x 15 cm wide
and scrubbed the oxid layer away with sandpaper of the aluplate and then
applied to the blank surface a mix of SIO2 and graphite powder, which I had mixed
very well with my electric coffee mixer.
I took some tap water to make the graphite-SIO2 mix wet like a paste and
painted this as a small layer directly onto the aluplate surface.
As the aluplate immediately build up an Aluoxid layer we have a very small
layer of maybe a diode there at these surface layer.

The result is, that in the wet state we have a battery cell of about 0.5 to 0.6 Volts
between the wet sand-graphite mix and the aluplate and a shortcircuit current of
about 1 to 2 mA can be drawn.

Then I put the aluplate on my oven and heated the plate with the sand-graphite mix
on it so that all water was evapouring and going off the mix.

When the aluplate? was finally pretty hot, so I could not touch it anymore
and the water was gone, the voltage was going down to almost zero and
also no current could be pulled anymore from the plate.

So this was rather disappointing, as I have thought, that maybe some
electrical output could be generated in a dry state without the galvanic
effect as in the wet state...

Okay, I did not wait until the plate was totally cooled down and I scrubbed
down again the mix from the plate and this time I added tablesalt ( NACL)
to the mix, made again a paste with water with it and again
painted it onto the plate as a thin layer of maybe 1 to 2? mm thickness.
Now this time the wet state generated much more power:
about 0.7 Volts and the short circuit current was around 3 to 5 mA !

When I then began to heat the aluplate again on the oven
the shortcircuit current also went up to about 10 mA.

Then when? all water has dried out of the paste mix,
the voltage of the cell was only 0.13 Volts and the
short circuit current was only 1 mA.

So well, it seems when one heats the plate too fast
and too long, that all the crystals that form in the mix
will be destroyed and the needed surface layers of the aluminiumoxid
are somehow destroyed.
It seems this cell only works well due to the galvanic effect in a wet state,
but if NACL is added also in the dry state there is still some output.

I have to recheck this again by letting the pastemix dry much slower
itsself, so one can see, if in the dry state there is more output then,
when the saltcrystalls can grow slower and more stable inside the
paste.

I will let you know.

Enclosed is a picture of the plate with just the graphite-sand paste
in a dry state ontop of it.
I just placed the meter with one pin ontop of the graphite-mix and
with the other tip directly at the aluplate.

Regards, Stefan.
P.S: if you click onto the small thumbnail you will see the picture in the original
640x480 size. This picture was made with my mobile phone, so it is a bit unsharp.Sorry.

[hartiberlin]

P.S: It could be, that in the second test with the added NACL
I did not remove ALL water from the mix, cause I did not heat it too long
and as the NaCL is a bit hygroscopic ( tried to suck in water from the air)
that there remained some water inside the paste mix and thus
all output is only due to galvanic action
and not the effect that Hutchinson and Markus Reid have in their
crystall batteries.

I guess I must retry it with the same salts that Markus Reid is using.

Regards, Stefan.

[hartiberlin]

Now after about an hour later the cell is up again to
0.25 volts open circuit and 2.5 mA short circuit current.

Maybe the salt in the mix has attracted now again some
water from the air, so now the galvanic process has started again ?

[hartiberlin]

Now after again about 1 hour later the cell has gone up to 0.32 Volts open circuit
and shortcircuit current is 3.5 mA.

[gast]

Stefan, do you use a second plate on the top side of the paste graphite-SIO2 mix?
How you did the voltage measurement? By putting the probe head of you voltagemeter directly into the dry mix and the other one on the plate? If you use a second plate on the top of the mix the contact-surface between the mix and the two plates should be much larger - and maybe the amount of mAmpers too?

How about using 2 plates with your mix between which are applied by a low DC voltage during the drying-process?
Maybe the current have any organising effect to the forming of the cristall-structur?

Bye.. Gast