Cited as a reference
Lithium Ion Battery Explosion
Why people recommend it
Footage of a lithium-ion battery exploding, linked as a warning before people experiment with charging cells without proper protection circuitry.
In their words
Note: Since you are dealing with very dense batteries that if overvolted can go up into flames [Note: please mute your speakers!], make sure to go with Sparkfun/Adafruit/etc...
Anonymous Penguin on arduino.stackexchange.com, Mar 2014. CC BY-SA.
Please be careful using it without protection circuitry.
jay on electronics.stackexchange.com, Sept 2021. CC BY-SA.