[Coulomb]

Originally Posted by david85

The electrolyte that the older ones I saw used was KOH (potassium hydroxide) which is a decently corrosive chemical.

Yes, almost as bad as sulphuric acid, found in millions of lead acid batteries for a hundred (?) years. I don't know if the newer ones need this electrolyte. Acids and bases are common electrolytes, of course, because of their good conductivity.

Lithium batteries have no liquid electrolyte in them.

Err, the prismatic LiFePO4 cells (e.g. Thunder Sky) typically have some liquid, which some call electrolyte, and I've heard the term "lithium hexaflouride" used, but it's not clear to me whether this is actually active material, or just conducting heat to the case.

[_GonZo_]

Lithium batteries have no liquid electrolyte in them.

Lithium bateries have liquid inside, the electrolite.

Li-Ion on hard case is liquid.
Lipoly cells in bag have gel.
Life cells is liquid.

[david85]

My understanding is that LiPo batteries use a synthetic solid electrolyte. Haven't looked at it in a while though, so I'll take your word for it that I am wrong. I don't have as much time for research anymore. Main point I was trying to make is there isn't a large amount of fluid sloshing around inside (which the pumping method of fuel cell would require, for example). There may be some liquid, but its not something that will cause a significant amount of spill in a failure situation.

Here are the experimental batteries that I mentioned earlier:

Lithium sulfur
http://www.sionpower.com/technology.html

Lithium "super polymer" (this is the one that exxon played a role in)
http://www.greencarcongress.com/2005...00_ev_to_.html

Company website
http://www.electrovaya.com/Default.aspx

Looking at electrovaya's more recent website, they seem to be distancing themselves from the 400wh/kg target. I can't find if anywhere in the up to date documentation. Perhaps they were blowing smoke. I remember years ago they specifically stated the 400wh/kg was in the works but its gone now.

All the more reason projections on paper aren't worth much IMO.
If this works well, than I wish you good luck but I can't believe any claims until I see the proof.

Lithium sulfur is said to have a theoretical limit of over 2000 wh/kg. Sounds great but getting results seems to be a bigger challenge than stating numbers or making claims.

[david85]

Just to clarify, I was also wrong to say that a 400 wh/kg battery was being marketed. The one I was thinking of is in fact closer to 250.

[major]

Originally Posted by PhantomPholly

The down side is that they only exist in laboratories.

As for how safe the fluids are or what the actual production energy density will be, it is all "vapour-ware" at this point.

Hi Phantom,

Look over http://www.electric-fuel.com/EV/index.shtml

A guy I work with did a contract job about ten years ago making the can and subsystems for a zinc-air bicycle battery. I think it worked, but the developing company kind of disappeared. I remember them making a big deal about having to get all the carbon out of the air electrode. Which wasn't easy.

But the company I linked to had buses running on zinc-air for years. Not sure they still are. I think the technology is more than vapor-ware. Ready for prime time? Probably not.

Regards,

major

[PhantomPholly]

Originally Posted by major

Hi Phantom,

Look over http://www.electric-fuel.com/EV/index.shtml

A guy I work with did a contract job about ten years ago making the can and subsystems for a zinc-air bicycle battery. I think it worked, but the developing company kind of disappeared. I remember them making a big deal about having to get all the carbon out of the air electrode. Which wasn't easy.

But the company I linked to had buses running on zinc-air for years. Not sure they still are. I think the technology is more than vapor-ware. Ready for prime time? Probably not.

Regards,

major

I hear ya. Buses are by nature nearly a laboratory environment, with strictly controlled routes and daily inspections/maintenance. A small prototype run using buses is, in my mind, is simply "Laboratory Phase II" - but that is purely subjective.

The acid test (pun intended) is whether they can make a profit. Sounds like they couldn't back then, maybe this new group will figure it out.

[_GonZo_]

I have to say that the people that have contacted me in order to start developing hardware sistems for metal-air cells, they are still on developing process.
Actually they are quite far away to start producing any tipe of cells.

At the beguing as per what they said they had running experimental cells over 500Wh/Kg.
Finally what they have is just calcualtions about wat they are supose to do, but they do not even have one of those experimental cells running.

So sorry for the smoke.

Any way this weeks I have been studing about them quite a lot (I think that now I know more about them than some people at that company )
And actually metal-air cells look very interesting, and I am almost sure they will become real soon for EVs

[david85]

Originally Posted by _GonZo_

I have to say that the people that have contacted me in order to start developing hardware sistems for metal-air cells, they are still on developing process.
Actually they are quite far away to start producing any tipe of cells.

At the beguing as per what they said they had running experimental cells over 500Wh/Kg.
Finally what they have is just calcualtions about wat they are supose to do, but they do not even have one of those experimental cells running.

So sorry for the smoke.

Any way this weeks I have been studing about them quite a lot (I think that now I know more about them than some people at that company )
And actually metal-air cells look very interesting, and I am almost sure they will become real soon for EVs

I seem to remember reading about aluminum cells and lithium-air cells too. Hypothetically, they could have crazy high energy density but until they are made for real, who knows......

Thanks for clearing that up. We try to stay as accurate as possible here. I say try, because as you can see, I just made the same mistake with that lithium superpolymer battery.

[PhantomPholly]

Don't give up hope - with new announcements almost every day, ONE of them will be real.

[david85]

Originally Posted by PhantomPholly

Don't give up hope - with new announcements almost every day, ONE of them will be real.

Agreed....