Comment Re:Still not solid-state. (Score 1) 23
The risk is when it has a full charge and has this happen. More of these batteries (Specifically Li-Poly) set fire due to damage (First) followed by the resistance and heat from incoming power (charging).
The damage (drops, crushing, too high of operating temps) causes layers to seperate, causing more resistance to any process, and then something stresses it (charging). this is is how you get spicy pillows. Li-Poly will also not rupture, if there's no energy to go out of control. It's similar to nuclear materials. There's inert (not going to go critical on it's own) and then there's Fissile (think "tickling the dragons tail" from the "demon core"). in normal conditions, may not be dangerous, but it's a fraction of a second and bad idea to release a shit ton of energy all at once. The more excited and pent-up that suppressed energy is, the worse the explosion when released all at once.
Yeah, I can puncture a large oxygen tank with no issues, if it's near empty and not under full charge. But charge it up and then do it. It's a good example of why they want batteries to be dead/drained if you transport them, and I have been experimenting with a lot of different battery types lately (Li-ion, LiPoly, NiMH, NiCD, etc...) and LiPoly scares the shit out of me knowing that a fully-charged one that is bad and only the size of a piece of chewing gum can burn your entire house down.
The chemistry does influence how it stores those energies, as well as how quickly it releases. Li-ion had this issue in the 90s due to how charging set things on fire. I'm thinking of that story with the sony cells and the Boeing 737 being grounded after a battery fire, which occurred during a charging cycle. It got better, but thermal issues, especially if damaged is the biggest danger here. And if we can lower the heat accrued during charging, the less stress it causes on the cells as well. Heat is a big enemy of that, and chemicals that change that release on sudden breaking of container, can be the difference between making it to the ground in one piece, or becoming the next flaming lawn dart. But it has to start somewhere.