What's Wrong With Lithium Ion Batteries?

An anonymous Coward writes "Lithium ion batteries short-circuit. They overheat. They burst into flames. The reasons behind the recent spate of problems with a technology invented by Sony more than a decade ago are complex and varied, making for one big engineering headache."

Comments

Everyone is trying to kill us...

[arorra500]

We have lead in children's toys, combustible batteries, slime in the Ice machine, one can only wonder what will they think of next?

Re:What's wrong? They store to much energy!

[joto]

Any battery will explode if a serious enough malfunction occurs, the question is what you consider "serious".

Batteries are typically used in portable devices. Thus they can never be 100% protected from damage. It would be pretty bad if the batteries in you ipod in your pocket decided to explode because of the impact you got in a car crash. Sure, car crashes are bad for you, but explosions even worse, at least when they're next to your skin.

I therefore suggest the following two tests for battery safety (for now):

1. Severely damage the casing (such as by driving a nail through it, or subjecting it to an anvil and a sledgehammer for a few hundred blows). If it catches fire, explodes, or leaks significantly dangerous substances to hospitalize you if exposed, it's dangerous
2. Hold the battery in an open flame for at least 10 minutes. If it explodes, it's dangerous.

That's what I mean by saying energy density is dangerous. Modern batteries contain so much energy that it's very hard to imagine something that wouldn't fail these two tests. And even if you protect them by a very solid shell, you're still going to get worst case once in a while. I'm not saying that we should go back to using alkalines only, but people should be aware of the dangers. Batteries are not toys anymore.

Solution!

[Fizzl]

Don't pack so much energy into such small package! Use conventional lead batteries instead!

Seriously, the problem is that the technology has excellent properties of low internal resistance and high capacity per mass. If the pack shorts for reason or another, all the energy is released in short order, causing it to practically explode.

There is also another problem. The charging. The Li-Ion/Polymer batteries will not chemically stop charging when they are "full" in terms of what it is supposed to hold. You can overcharge the pack until it gets unstable and finally shorts itself, again causing the explosion.

There is nothing you can do to the electrochemical pair without losing its positive characteristics. External safe guards, such as charge cutters and current limiters can only do so much. The pack can still short internally.

Re:What a moronic post

[heinousjay]

wow. So you never considered what is essentially the purpose of the court system as the purpose of the court system? I can pretty obviously not factor your opinions in the future.