Paper-thin batteries power IoT tiny tech

The EFL700A39 EnFilm rechargeable batteries are

The rechargeable batteries are 220-µm thick and measure 25.7 x 25.7-mm. The solid-state lithium thin-film battery features surface-mount terminals that allow direct attachment to the circuit board. With 3.9V nominal voltage and 0.7-mAh capacity recharges from a 4.2 V charging circuit and displays low capacity loss and allows about 10 years of use if charged once per day. It is RoHS compliant and UL certified, satisfies UN tests and criteria for battery transportation, meets IEC 62133 safety specifications, and meets the ISO7816/IEC10373 mechanical and flexibility standards for smart cards. Engineering samples and small production quantities available $30 ea/5.