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I just read about yet another Lithium ion battery spewing flames (
http://www.wsbtv.com/news/14271878/detail.html). This one was from an iPod Nano, but it would be unfair to claim that it happened because it's an iPod. In the past we've all likely seen or heard of the Dell laptop that caught fire in Japan, and the ur-event itself, the first portable Mac that did the same. And how could one have missed the massive Li-ion battery recall of just a year ago, which affected pretty much every brand of laptop in the market. The latest is the Nokia recall of Li-ion batteries, specifically the BL-5C. See
http://batteryreplacement.nokia.com.
The problem with Li-ion batteries is their ability to self-ignite under certain conditions. This is best described in an article all by itself, and here are two good links for it:
http://computer.howstuffworks.com/dell-battery-fire.htm and
http://en.wikipedia.org/wiki/Lithium_ion_battery.
Now it's obvious that there are many safeguards built into Li-ion batteries, and considering their massive use in most portable electronic devices, the number of failures is very small. But what's next?
I usually don't like to ring the caution bell, but the potential for trouble from Li-ion is significant. Had the Dell laptop fire occurred on-board an aircraft, instead of inside a meeting hall, it would have posed a whole new set of challenges. No, I don't believe a plane would catch fire or crash, but it would be a very unpleasant experience for many.
What I'm worried about is the aggregation of more Li-ion batteries to achieve with battery power what used to be done using other forms of energy storage. Mainly I'm thinking of electric cars, but this concern is not limited to the application itself.
On the upside, electric car batteries can employ additional safeguards that are difficult to implement in size- and weight-limited portable electronics applications. However, while portable electronics can expect the occasional drop, they don't have to undergo a 60-to-0 transition with significant plastic deformation of the containing frame (fancy words for a high speed crash).
I don't believe the question as to what happens to lithium ion batteries when they are violently deformed and short-circuited has been explained with sufficient clarity. Wishing or by calculation determining that there is no issue is akin to the thought process that left the Ford Pinto fuel tank the way it was.
Then again, if we were all worried about trying new things out, I would have taken a horse buggy to work today, and I'd be writing this out by hand, dipping my pen into a container of ink to recharge it every now and then.
Perhaps the middle ground is to be aware of the issue and look for better alternatives. Not too long ago I had an interesting conversation about the new breed of super capacitors coming out. The applications are endless, such as notebook battery recharges in seconds, but the repercussions of short circuiting one of those can be even more spectacular than with Li-ion. But that's a bit too far out for us to worry about for right now. Suffice to say that it's the consumers who decide what they buy or don't buy. Sadly, the car industry figured out the hard way that safety does not sell. Will it be the same for electronics?
