Just a month ago, we covered the story of Nokia issuing a world-wide recall of a whooping 46 million lithium-ion batteries. Apparently, the batteries made by Matsushita Battery Industrial could potentially short circuit and overheat, and so they had to be withdrawn as a safety precaution.
However, this is only the most recent of a seemingly endless stream of product advisories and recalls involving batteries made with lithium-ion technology over the past few years. If you are like me, you must be wondering why these problems continue to surface more than 10 years after Sony invented the technology back in 1990.
Well, I saw a piece on Electronics Weekly titled, "What's wrong with lithium-ion batteries?" that neatly answered most of my questions.
If I may surmise, the problem boils down to two main issues, according to the article.
- Li-ion battery technology is a constantly evolving technology, driven not only by the desire for cost-reduction but also to meet ever increasing demand on performance in both energy density and cost.
[It is pointed out] that Li-ion battery technology is not just a single design or composition, but rather it’s an entire family of chemistries that is constantly evolving. “When Sony invented it in 1990, it was lithium cobalt oxide. But cobalt is expensive, and so engineers started replacing it with nickel, which costs less. And then as time went on, engineers found that they could substitute cheaper nickel manganese alloys for the nickel.
- Part of the problem could be the result of difficulties in guaranteeing quality due to manufacturing practices. Also, a battery pack, once assembled, cannot be inspected from the outside nor tested easily. The cells for the battery in the Nokia advisory, for example, were manufactured by MBI in Japan but assembled into battery packs in China.
[Don Sadoway, a professor of Materials Chemistry at MIT] points to the separator material between the electrodes as an example. Acting like a kind of fuse, it is designed to soften and collapse at a specific temperature, causing the battery to essentially go into an open circuit condition and die.
“You could think you are specifying a porous polypropylene material for the separator, but once the thing is packaged up, you would have no way of knowing what you actually got... What if the workers took a short cut and substituted the original material with cardboard?”
So, there you go. Next time you consider purchasing that cheap lithium-ion battery pack at the flea market, think again.
Also, I previously wrote a piece about 3 things you should already know about your lithium-ion battery. Hopefully that will help you properly maintain your precious "Made in Japan" battery.