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Tesla's /cells/ are also "fundamentally unsafe", but they make the /batteries/ as safe as possible. Fundamentally _safe_ would be LiFePO4 chemistry: http://en
by coryrc 14y ago
Tesla's /cells/ are also "fundamentally unsafe", but they make the /batteries/ as safe as possible.
Fundamentally _safe_ would be LiFePO4 chemistry:
http://en.wikipedia.org/wiki/Lithium_iron_phosphate_battery http://en.wikipedia.org/wiki/Lithium_iron_phosphate_battery
Longer lifespan and significantly cheaper than cobalt, manganese, etc; but 20% lower specific mass. Survives having a nail driven through a fully-charged cell with only some smoke and a small bit of flame -- not a meltdown like the more active chemistries.
- bigiain 14y ago"Tesla's /cells/ are also "fundamentally unsafe", but they make the /batteries/ as safe as possible." While it's certainly true that the Li-ion chemistry used in the Tesla's batteries are flammable, keep in mind the current common alternative to those potentially burning cells is carrying round a metal or plastic tank with 10 or more gallons of gasoline in it. If there weren't a 100+ year history of people doing just that and getting away with it most of the time, you surely wouldn't be allowed to do it in today's safety-conscious society.
- Retric 14y agoGasoline is not all that dangerous in the vast majority of failure modes. Li-ion is both corrosive and easier to set on fire which is a real issue for hybrids and aircraft.
- btilly 14y agoVast majority, yes. But I've seen failure modes where it was dangerous on more than one occasion.
- ricardobeat 14y agoGasoline isn't dangerous? It's ten times as easy to light up a gas tank than a battery pack, and the energy release is instant.
- rosser 14y agoYou can drop a lit match into a bucket of gasoline. It needs to be aerosolized to be explosive.
- kragen 14y agoYou can indeed, and it ignites the gasoline. Gasoline vapors in air have relatively wide explosive limits which can be attained in a wide variety of ways, not only by aerosolization.
- rosser 14y agoThen the multiple times I've seen that done, by multiple different people, all happened with something other than gasoline. I'm not saying it can't happen, and I'm well aware that gasoline vapors are extremely dangerous. I'm just saying that the gas tank in your car isn't "10 times as easy to light up" as the newer, super-energy-dense lithium chemistry based batteries.
- kragen 14y agoDiesel fuel and kerosene are good candidates for the "something other than gasoline". They'll both happily put out a lit match.
- kragen 14y agoMay I suggest, by the way, that you think twice and double-check your facts before posting potentially fatal fire-safety advice on the internet? You'll probably never know if you've killed somebody. If you want to try the gasoline-bucket experiment, I recommend doing it in a small coffee can on a large concrete pad that you don't mind discoloring.
- rosser 14y agoI think the critical difference is how long the bucket full of gasoline has been sitting there. If you just filled it up, there will be a lot of vapors hovering above the surface. If it's been sitting, undisturbed and uncovered, for a good long while, there won't. In the former case, you're going to lose your eyebrows, at best. In the latter, the match will go out.