More Lithium Battery Product Recalls Predicted (mercurynews.com)

While "the vast majority" of lithium-ion batteries will never malfunction, lithium itself "is highly combustible and batteries made with it are subject to 'thermal runaway'," which can be triggered by damage -- or by bad design. An anonymous reader quotes the San Jose Mercury News: Battery and electronics manufacturers take numerous steps to try to mitigate such dangers... But while the industry has tried to make lithium-ion batteries safer, 'the technology itself isn't foolproof,' said Ravi Manghani, director of energy storage research at GTM Research... And there's reason to think that the problem could get worse before it gets better. Consumer demand for devices that are ever more powerful and longer lasting has encouraged manufacturers to make batteries that can hold even more charge. To do that, they typically pack the battery cells closer and closer together...

Since June of this year, educational toy company Roylco recalled 1,400 light tables designed for kids... Razor, Swagway and some eight other manufacturers recalled a total of 500,000 hoverboards. And HP and Sony between them recalled more than 42,000 notebook computers. All for similar reasons -- lithium-ion batteries that either had caught fire or which have posed a fire hazard... Other notorious examples include the several different Tesla Model S's that have caught fire, typically after crashes compromised their battery packs, and Sony's wide-scale recall a decade ago of the batteries that powered its Vaio and other laptop computers.
In a related story, Samsung's recall of their Note 7 is now expected to cost $5.3 billion.

Comments

Li Fe P04

[goombah99]

It seems to me this battery is the one we've been waiting for. Yes a little less peak energy storage but it's thermal properties and lifetime mean that it can be recharged fast and will degrade less over the life of the phone. Effectively that means in practice the phone will perform better than Li ion. I don't think it's going to cost more either. Yes right now it is slightly pricier but it doesn't have the economy of scale working for it yet so the jury may be out on that.

Is it just thickness then? That's short sighted.

It does have one double edged sword. It's voltage is 3.2v so it's absolutely perfect for running 3.3v chips right off the battery without a regulator. 3.7v is slightly above many 3.3v chip max voltages so you end up with a regulator and that's a loss. You can run the 3.2v Lifepo4 all the way up to 3.6V at max charge but at anything less than 95% charge it's under 3.4v making it safe at all times for 3.3v electronics.
The flip side of beinbg below 3.6v is if you really do need a regulator for some reason then your V_drop has to be very small and you don't have much headroom above the minimum regulator voltage, or you have to drop the operating voltage down lower than 3 volts. A lot of 3.3v chips tend to start sucking current hard when you drop them below 3v so that headrooom matters in a big way.

Re:It's simple

[Streetlight]

Even though Samsung has said they don't know what caused the problem in the Note 7s, I have a theory. In the drive for thinness the battery is squeezed very tightly against the other internal parts of the phone. Charging and discharging will cause expansion and contraction of the battery and in the tight environment some warping and bending might occur causing breaking of the outer battery skin. In addition if the battery comes in contact with sharp or pointed components in the phone expansion could result in pierced battery skin. The result is leakage of the liquid ether containing liquid electrolyte. These are organic ethers, not diethyl ether once used as anesthetic, but more complex, higher molecular weight compounds. Ethers coming in contact with air form peroxides which are spontaneously explosive and flammable. This might explain why the phones burn when not in use as the accumulated organic ethers take some time to become oxidized to peroxides.

The suggestion by earlier posters that phones should contain customer replaceable batteries might mitigate what I have suggested happened. The design of the batteries I've seen for phones with replaceable batteries (like my wife's Samsung Galaxy S4) were contained in substantial metal cases to be placed in a cavity in the phone protected from internal phone components. Maybe the phones would the somewhat thicker. So what?