Device, not the battery
Li chemistry batteries are very power dense and have to be handled accordingly. They shouldn't be overcharged or over-discharged and regulated so they they aren't being asked to supply more power than they are capable of delivering.
Most cheap Chinese electronic junk isn't built with proper battery protection. It is entirely possible that the vaping unit sucked the battery below it's minimum voltage and past its maximum current one too many times. You get what you pay for. Next time, buy an 18650 cell with built in protection.
Biting the hand that feeds IT
