Not 18650 but related. Recently I've been salvaging li ions from disposable vapes. Usually they are between 2.6 and 3.3v depending on how long it's been sitting. This one was at 1v.
3.7V polymer lithium battery 102040 750mah Bluetooth audio hydration beauty instrument hydrogen rich water cup battery|Smart Accessories| - AliExpress
How to Find Free LiPo Batteries From the Street and Use Them in Projects : 7 Steps - Instructables
MPF Products 350mAh BAP 800 Battery Replacement Compatible with Sennheiser Flex 5000, RS 5000, Set 880
Replacement units for Interphone Cellularline
Interphone cellularline F5MC Twin Pack Intercom Black | Motardinn
interphone battery, interphone battery Suppliers and Manufacturers at Alibaba.com