NiMH has been largely eclipsed by Li-Ion.
Li-Ion has quite a bit more specific energy and specific power.
They each have their specific issues, but in the
end, the specific power (and price) is what we are all after.
Can you even find a new NiMH cordless tool
anymore? All the new cordless tools have gone to Li-Ion.
Folks have been trying for a bi-polar battery for
quite some time. The costs remain quite high for
the gains in capacity. Nilar says it best
"Bipolar design has historically been the Holy
Grail of battery technology, but has historically been difficult to realize."
http://www.nilar.com/technology/
The edge seals are always the difficult part. Still is.
Bill D.
At 01:26 PM 9/9/2014, you wrote:
On 9 Sep 2014 at 3:20, brucedp5 via EV wrote:
> The Concept J is supposed to be powered by the Kawasaki's proprietary
> GIGACELL® ... nickel-metal hydride battery composed of individual cells
> that are connected in series at their cell walls, with the front and
> rear surfaces becoming the positive and negative terminals, forming a
> bipolar structure.
Interesting that they might use NiMH. This battery tech has largely been
forgotten in the rush to lithium. However, it's proven very reliable in the
old first generation Toyota RAV4-EVs. Many of them have gone well over
100,000 miles on the original battery.
The problem has been the obstinate refusal of the NiMH patent holder Cobasys
(originally Ovonics) to license BEV-size modules (anything over 10ah).
Perhaps the Kawasaki design evades the Ovonics patents by virtue of their
very different design. Or perhaps BASF, who IIRC now owns those patents, is
less restrictive.
Anyone know what might be going on here? I'd love to see NiMH as a viable
and affordable EV alternative to lithium. OTOH the word "proprietary" is
generally not a good sign in this context.
PS - is what they describe here a true bipolar battery? I'm not so sure. I
had the impression that in a bipolar battery the negative electrode of one
cell and the positive electrode of the next one in series were THE SAME
PIECE OF MATERIAL, not just two electrodes butted or welded together. Heck,
if butted electrodes defined a bipolar battery, then the battery in my
flashlight is bipolar, no?
David Roden - Akron, Ohio, USA
EVDL Administrator
_______________________________________________
UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
http://lists.evdl.org/listinfo.cgi/ev-evdl.org
For EV drag racing discussion, please use NEDRA
(http://groups.yahoo.com/group/NEDRA)
