Driving Green, Explosion-Free - GreenHybrid

lars-ss · #1 (**permalink**) 08-26-2005, 10:02 AM

Maybe this battery technology coming into Gen 4 or Gen 5 hybrid cars? Already in the newest Segways:

http://www.wired.com/news/technology...?tw=newsletter

Quote:

"It's an enabling technology," said Dean Bogues, Valence's president for North America and Europe. "We think, as batteries get better, that reliance on batteries to provide energy in your car will get larger."

Quote:

Lithium ion batteries are more energy-dense than nickel metal hydride cells currently used in most hybrid and electric cars. That means a lithium ion battery can run at a higher power for a longer time than a nickel metal battery of the same weight. But most lithium cells use a cobalt oxide chemistry that can catch fire or explode if the battery is charged or discharged too quickly, or if it is physically damaged.

fernando_g · #2 (**permalink**) 08-26-2005, 12:23 PM

The worst PR that can happen to hybrid vehicles, is that one, anywhere in the world, catches fire due to a battery failure. The media would have a field day.
I can imagine the headlines:
HYBRID VEHICLE OWNERS TRADE MPG FOR LIFE AND LIMB

Lithiums, due to its extra high energy density, could be particularly worrisome.
Perhaps that is the reason manufacturers have shunned away from them.

Now, batteries are not the only "risky" new technology. If any of the hydrogen powered vehicles catches fire or explodes, it will immediately be linked to the Hindenburg. Again, the media will have a field day.

Wangofree · #3 (**permalink**) 08-27-2005, 01:23 AM

We always think in terms of "one or the other" when it comes to identifying utilization of an item. We are surrounded by items that use lithium batteries, our laptops, pda's, etc. I wonder if car manufacturers could use both types of batteries. Say 30% lithium, 70% NMHydride. (I'm making this up as I go along). So, say your system charges the lithium battery component until it reaches a "danger" point, then switches to charging the NMHydride battery. Or it "pulses" between the two so that the Lithium never "charges too fast". Maybe it doesn't have to be an "all or none" approach to using lithium cells.

Schwa · #4 (**permalink**) 08-27-2005, 01:45 AM

The Valence batteries don't have the risk of explosion or 'venting with flame' as they call it in in batteryland because of their chemistry, so they can handle an overcharge or rapid discharge without the expensive protection circuitry that the traditional lithium cells in laptops and cell phones require.

The main reason cars aren't using lithium cells is that they don't last as long, even if you don't use them they degrade in performance in a much shorter time than NiMH cells, so they couldn't confidently offer a warranty that they can with the nickel cells. The secondary reason is cost, since the lithium batteries cost more, especially when they require the thermal and electronic protection systems integrated with each cell.

If the Valence cells prove themselves in the test of time, then they may become the new automotive standard, and it looks like they just might. Manufacturing plants are being constructed in China, so looks like they are pretty confident in their performance.

AZCivic · #5 (**permalink**) 08-27-2005, 09:29 AM

LiIon is cool!

http://www.valence.com/broadband.wmv

fernando_g · #6 (**permalink**) 08-28-2005, 09:32 AM

A combination of batteries and supercapacitors may be the answer... this solution is already employed on mass transit hybrid buses.

higher $$$$, though

Schwa · #7 (**permalink**) 08-28-2005, 09:46 AM

Supercapacitors have some lifespan issues, although that is being worked on. They do have vastly superior charge cycles as compared to batteries, somewhere in the range of 500,000 - 1 million cycles.