Why are lithium-ion batteries typically used if they’re so flammable?

It’s no secret that lithium-ion batteries are volatile - just look at hoverboards, Samsung Galaxy Note 7’s, and even some iPhone models which have exploded. Granted that these are not so common occurrences, but the fact that they happen at all is still troublesome. Lithium-ion batteries are not the only type of rechargeable battery out there; why don’t electronics companies try a different type of battery, like nickel-cadmium, or nickel-metal hydride? Is there a benefit in using a lithium-ion battery, or does it just come down to what’s easier to mass-produce?

• Have you googled this one yet? – Bort Jan 11 '18 at 1:30
• @Bort Yeah, but I didn’t come up with anything. Am I just that dull with search engines? – DonielF Jan 11 '18 at 1:31
• why do you use a toaster when it can electrocute you or it can start fires? – jsotola Jan 11 '18 at 3:39
• @jsotola Avoid sticking metal in the toaster and make sure there’s no exposed wires, and unless you’re intentionally trying to do something like that, you should be fine. – DonielF Jan 11 '18 at 4:00

Li-ion is primarily chosen for higher energy density (by weight and volume), but also for higher power, higher voltage, more flexible form factor, cheaper and easier manufacture, more efficient charging, lower self-discharge, more cycles and higher reliability than most other battery types.

Why don’t electronics companies try a different type of battery, like nickel-cadmium, or nickel-metal hydride?

They have. Cadmium is a heavy metal, so Nicads are out. NiMH batteries were used in phones and laptops before Li-ion took over. Charging them was always a problem due to heat generation and the difficulty of accurately detecting full charge.

lithium-ion batteries ... have exploded. Granted that these are not so common occurrences, but the fact that they happen at all is still troublesome.

You know what's really troublesome?

17 car fires every hour in the US, killing an average of four people every week.

Yet nobody is concerned enough to stop using gasoline, because its enormous energy density (effectively 20 times greater than Li-ion) is worth the risk.

• That last bit is fair, and it makes me feel bad now that I phrased my question the way I did. :/ That said, how many of those explosions were from alternative-fuel cars? While the primary reason many people are switching away from gas cars is because of the environment, if there’s no gas to explode, wouldn’t there be less deaths due to car fires? – DonielF Jan 11 '18 at 0:23
• @DonielF, electric cars catch on fire, too, especially if the batteries are damaged in a collision. I sincerely don't know for sure which one is worse, though I suspect gasoline cars to be worse. – mkeith Jan 11 '18 at 1:38
• Of the few fires that have occurred in electric cars, most were not caused by the battery, and many did not involve the battery at all. They do appear to be safer... Plug-in electric vehicle fire incidents – Bruce Abbott Jan 11 '18 at 5:31
• For those interested, adding kerosene/gasoline to the chart would make it almost impossible to see anything else. By liter, it's $10.4\times 10^3$ and $9.5\times 10^3$, respectively. By kg, it's $11.9\times 10^3$ and $12.9\times 10^3$, respectively. Both are very, very efficient storage methods for energy, since atmospheric oxygen is "free." And they are both liquids and easily transported, poured, etc. Kerosene is particularly safe - it doesn't readily ignite. Reasons why it is hard to replace such fuel in cars. H2 might compete, but >10,000 psi storage makes containing it very hard. – jonk Jan 11 '18 at 17:21
• "adding kerosene/gasoline to the chart would make it almost impossible to see anything else." - true, but not really a fair comparison. The difference isn't quite as extreme when you factor in the equipment required to make use of it (gas tank, heavy engine, exhaust, cooling system, starter battery etc.) and the much lower efficiency of a gas engine. – Bruce Abbott Jan 11 '18 at 18:27

They have high energy density (watt-hours/cubic meter and W-h/kg). They generally have a long life and the price is competitive. Some of the explosion problems have likely been due to poor battery design, poor load product design and poor manufacturing quality. If these problems are solvable or have already been solved by some manufacturers, that type of battery will regain its reputation.