Complex and explosive chemisty?
That's it, no more batteries for me.
I'll stick to safe and simple combustion.
I know you joke but:
- gaz (petrol) doesn't explode (unlike what Holywood has taught you), it just burns.
To make it explode you need the perfect mix of oxygen. Hence the complicated fine mechanical components in a internal combustion engine (pistons, manifolds, etc.)
Fun fact: you could in theory make anything that burns explode by making a correct mix with oxygen:
- a big block of wood just burns. Saw dust suspended in the air burns explosively
- grain might burn if dry enough. But you can actually make bombs out of flour suspended in the air
and the one that every chemistry and fireman know:
- gaz (methane/buthane) at the gaz burner just burns. (hence the name, duh). On the other hand, a roomful of gaz (gaz + air mix) + spark....
The reason why we use gaz (petrol) inside most cars is due to energy efficiency. But you could make explosion out of anything BUT NEED TO MIX AIR FOR IT TO WORK.
- On the other hand :
Lithium is highly reactive. (Well the whole point of a rechargeable battery's chemistry is to have a lot of electrons that you can easily move around [=easily make red-ox reactions]...)
It has a nasty tendency to explode (if you over-charge, if you undercharge too much before recharging, if you draw too much current, if you charge too much current, if you overheat, if you puncture, if.... well basically if you look at it the wrong way).
Luckily that's why nearly all modern lithium batteries have built-in electronics (a.k.a.: "battery manager") to control and protect them.
(That's what the third pad in addition to "+" and "-" on smartphone batteries is: it's a data channel to communicate with the built-in protection and get some extra informations, like temperature).
Well "nearly all"... /. and Youtube kindly remembers for you a certain batch of Sony laptop batteries with faulty built-in managers that had several laptops burst into flames.
Fast forward a few years later and we see again the same faulty batteries with the cheapest and shittiest "hover board" self-balancing boards out of China.
That's one of the major fallacies in Oatmeal's strip about his new Tesla car (but yeah he's a cartoonist, not a chemist):
the gaz in the tank of a ice-powered car is *theoretically* a lot less dangerous than the lithium in an electric car's humongous battery.
(there's no explosive liquid stored anywhere near the balls of an ICE driver. The electric-car driver is the one sitting above a big mass of lithium no matter how far away is the sun that was used to charge the battery).
Luckily in practice, Tesla isn't like the shady Chinese companies making craptastic batteries mentioned above.
They do the necessary design to make the battery secure and in *practice* their car aren't explosive (despite all the bad mouthing around the 2-3 fires reported).
But to go back to the subject of the discussion and my above post :
well that's why Tesla's 100kWh battery cost so much more. battery are expensive, because of all the above.
Want more gaz ? Just make a bigger jug to store the gaz. At worst, if its catch fire, it's going just to burn a little while longer. That's it.
Want more electricity ? be ready to pay a lot, battery are complex and you need complex electronics to regulate the electricity that goes in during charging or that goes out to power to motor, because if you don't you're in for quite some fireworks (see Sony laptop batteries and Chinese self-balancing board maker for what happens when you fail to do your homework).
So modern car batteries in practice aren't dangerous, but that comes at a price.
(That's also why I'm highly doubting about the Chinese car manufacturer mentioned here on /. that wanted to make electric cars for free/paid by the ads.
To make the batteries that cheap, some very dangerous compromises might have been made).