Not to get too far ahead of myself...
With this battery thread going and a couple similar on "battery conversions"...
I've been trying to do "Mn-Mn" batteries - permanganate-manganese
batteries in moderately alkaline electrolyte. They have great voltage
and theoretical energy density (they charge to 2.6 volts!), but I've
been having trouble with high self discharge and low conductivity.
Yesterday I put together a "Mn-Ni" cell - permanganate-nickel also
"moderately alkaline". With this I should find out which electrode is
causing the troubles by whether they're still there or not with the
lower voltage nickel negative side. I put some graphite in it to up
the conductivity (but not as much as it really needed) as well as
using monel rather than pure nickel, for the conductive copper
content. Nickel as a negative has twice the amp-hours of nickel as a
positive because the reaction (Ni <=> Ni(OH)2, ~~-.5v) moves two
electrons insead of one.
Unfortunately I also used PLA plastic for the 3D printed case instead
of ABS, and discovered that it's immune to methylene chloride. So
this morning I bought some MEK, and that's sort of working. I just
reglued two corners that came apart when I flexed them a bit, and
clamped it together. Waiting for it to 'dry'. If it doesn't hold,
I'll have to see what I can salvage without starting totally from
scratch with an ABS case. (The 3D printer isn't working right now, so
cases are presently priceless.)
Plastic is cheap, manganese is cheap, graphite current collectors are
cheap, potassium chloride salt (electrolyte) is cheap, and
nickel/monel/nickel oxide powders are pretty affordable in the
quantities used. And the energy density and cycle life are
theoretically excellent.
Craig
http://www.TurquoiseEnergy.com/
=====
>That sounds like a great advancement, but it seems to me that the
>future is going to be in sodium, not lithium. Lithium is lighter and
>probably "better", but it's also relatively rare and expensive.
>Sodium is common and cheap. If we're ever going to have electric
>vehicles (including boats) we're going to have to have an affordable
>battery.
>
>Willie
>
>--- In electricboats@yahoogroups.com, Kirk McLoren <kirkmcloren@...> wrote:
> >
>> Scientists at the Department of Energy's Oak Ridge National
>>Laboratory have designed and tested an all-solid lithium-sulfur
>>battery with approximately four times the energy density of
>>conventional lithium-ion technologies that power today's
>>electronics.
>>
> > Read more
>at: http://phys.org/news/2013-06-all-solid-sulfur-based-battery-outperforms-lithium-ion.html#jCp
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