https://en.wikipedia.org/wiki/Lithium_iron_phosphate_battery or LiFePO4 has much better safety properties. Any device sold to consumers should be required to have temperature monitoring, over voltage and over current protection. If it fails any onboard safety check it should render itself inoperable.
That sounds like a good development. I'm especially concerned about stuff worn against the body (earbuds, sports wearables, watches, cellphones). Laptops and tablets are also potentially dangerous but it's not as if every fuck up will immediately lead to injury.
I review flashlights and headlamps as a hobby. Many modern high-powered ones use removable Li-ion cells, most commonly 18650 size.
Temperature monitoring has become very common. The primary heat source is almost always the LED, not the battery, but it would be sufficient to detect a battery nearing thermal runaway. Low-voltage protection is common, but sometimes only a warning blink rather than a hard cutoff based on the idea that leaving the user in the dark might be worse than damaging a battery.
Some models have onboard charging, most often through MicroUSB. Correctly charging a single Li-ion cell is not difficult, and I haven't seen one get it seriously wrong yet.
LiFePO4 has seen a little use, but is not popular due to its much lower energy density. I suspect this has kept it out of other portable devices as well since users always seem to want longer runtime in ever smaller devices.
It was popular for pro power tools for a while. Those get a lot of abuse, and people are constantly changing battery packs so they max out on charging cycles. DeWalt used LiFePO4 from A123 Systems. But they seem to have given that up.
I honestly wonder why. I developed a portable small-quantity project a few years ago and designed in a 20AH LiFePO4 battery pack; it seemed like the only sane choice. The cost was slightly higher and density was slightly lower, but the difference was less than 10%. Not having to be concerned with battery failure modes was a huge advantage. But those factors must be different at larger scales; the largest scale I can think of where density matters would be for a commercial electric 18-wheeler tractor; what chemistry do those use?
