Interesting Li-Ion battery article...

[SilverFox]

I ran across this interesting article looking toward the future of Li-Ion battery use in electric vehicles.

The next 5 years sound like they should be very interesting...

Tom

 

[MrAl]

Hi Tom,

Yes that's an interesting article.

What i am wondering is how the Li-ion cell will fade out once the really
new technology gets here...but i guess that could be a while off.
I started thinking about this while considering what the life expectancy of
a new charger design should be: 10 years, 15 years, 20 years, or 30 years?
That's when i realized that Li-ions wont be here forever, but im still aiming
for 20 years life expectancy just the same.

 

[LuxLuthor]

That is a great overall review of the various chemistries, pro's and con's of each, and the direction of lithium ion developments. As the current cobalt Li-Ion cells continue being abused and aging, I believe we will hear about some more battery failures....hopefully none ending in bad stories...but eventually to protect the consumer and the companies from lawsuits, moving in these safe chemistry directions just makes sense.

It would be nice to see more interest in smaller cell sizes that we use. That was interesting to read how A123 uses nanotechnology to improve the energy density. I suspect AW is running up against that limitation with his Iron Phosphate cells not having that technology.

There are some pretty hefty demands being placed on A123 by potential customers.

Thanks Tom!!! :thumbsup:

 

[LEDite]

Good Article, Tom

I liked the safety quote:

"Field failures occur once in every 5 million to 10 million of the most common lithium-ion cells, those known as the 18650 design, according to Brian Barnett, a technology analyst at Tiax, a consulting firm."

Larry Cobb

 

[SilverFox]

Hello Larry,

Yes, that is a very impressive safety record...

I wonder what the numbers are for NiMh cells...?

I guess if you follow the manufacturers recommendations, things go well.

Tom

 

[LuxLuthor]

I noticed that also, but dismissed the relevance to our CPF addictions. I see it as those "safe millions" are skewed from being in PCB protected laptop packs, and other lower drain, & low charging current applications.

I have to think our higher amp, fast hotwire draining, relatively high heat, and less stringent factory packaged charging solutions puts stresses on cells that are not reflected in those stats. Many use unprotected Li-Ions of questionable manufacturing quality, or charge in series with no awareness of cell balancing when used as individual cells.

I make some of my deductive suspicions of higher failure risk rates from evidence posted at RC forums, where they over abuse mostly LiPo versions. In addition, there are a surprising number of reported thermal Lithium Ion failures in topics here at CPF....certainly more than the one in 5-10 million incidence.

I'd also like to see a few more reports backing that number up.....just thinking about the number of laptop battery recalls doesn't seem to jive with that claim.

 

[Codeman]

...
I guess if you follow the manufacturers recommendations, things go well.
...

That's what I was thinking as well. I wonder how many failure occur when the root cause of the failure is inadequate controls that don't follow the recommendations? In other words, it's not the cells failing per say, but the surrounding circuitry (or lack of). Compared to the management circuitry in name-brand laptop packs, what is used in the light/RC community is extremely bare bones. Yet, look what happened with all the laptop packs a while back. Was the root cause the cells themselves, or the circuitry?

Regardless, we shouldn't make the mistake of taking a manufacturer's claim that was based on a tightly controlled environment and then use it to rate their products when we're actually using them in a different environment. Unfortunately, we have a bit of a gap between what we need for our light/RC applications vs what they can spec out. They simply can't test for all possible uses and provide specs that will always be accurate for all possible uses. It's up to the builders/users to determine how well a given implementation complies with the manufacturer's recommendations. Only when that is well understood can we begin to understand how those claims compare to real life usage.

It may be time to buy some A123 stock, assuming they're public...