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View Full Version : how thin can you go... foil as plates?



Owen_
12-30-2009, 02:29 PM
It seems logical that a thinner plate will have less resistance and improve efficiency. The problems would be cell design so the plates didn't short themselves out (possible) and how they hold up to use (maybe what kills my project).

how long do you think a .005" nickle plate would last? or 316L for that matter.
And what could be done to make it last longer?

With foil nickle vs SS is a different story. There is so little metal there isn't that much price difference. Also SS can be made much thinner than nickle as it is harder.
(still not sure where I can get some in a smaller quantity)
I have made some CAD drawings for a foil cell, but i think I should drastically simplify the design for a first test.

Roland Jacques
12-30-2009, 06:57 PM
I wonder the same thing at the time.

I can see a problem with electrodes that are to thin. Mainly due to the connections area of the tabs, being so thin they would be fuse like and get hot ... (Not enough cross section area for current in a 1" x .005" tab)

But I dont see how neutral plates can be to thin. (Aside from corroding out faster) Nickel being much more conductive and better corrosion resistant properties, i would thing current density could be maybe 5 to 10 times that of 304 Stainless.

Id like to find some comparative numbers between the two.

Owen_
12-30-2009, 11:40 PM
But that's not a problem for N plates, the pos and neg can be on the outside and backed with copper.

Roland Jacques
12-31-2009, 08:44 AM
As far as trying to use copper backing... not to practical. A thicker E trode would be much simpler.

One factor to consider, is current density you plan on running

Owen_
12-31-2009, 11:34 AM
true, but i'm not aiming for simplicity with this project. I'm trying to make a very efficient cell. The blue print I've drafted will take a lot of time to machine (with out a cnc mill that is), cutting reassessed pockets for copper plates in the outer plastic blocks only adds about 5% more labor.

The major draw back to this design that a see (other than the complexity of construction) is that it will have very little plate surface in comparison to "traditional" dry cells. Therefor in atomotive use it may end up needing to be the size of a bread box for usable out put quantity.

What might end this project before it starts is that is plate ware. Slight pitting on a 1/16" plate is no big deal, but the same on .005" foil could mean swiss cheese.

Roland Jacques
12-31-2009, 02:23 PM
What might end this project before it starts is that is plate ware. Slight pitting on a 1/16" plate is no big deal, but the same on .005" foil could mean swiss cheese.

You might want to cryogenically and electro-polish those thin plates if your going to put that much work in them.

Cryo will make them more resistant to wear and more conductive. E-polishing can make a better surface conditioning.

I hope to be testing both in the next few months