EFL700A39 EnFilm™ is a thin film rechargeable lithium battery from STMicroelectronics. It features all solid-state, ultra thin, fast recharge, long cycle life, RoHS compliant and UL file number: MH47669. It is intended to be used in sensors and sensor networks, smart card, RFID tags, energy storage for energy harvesting devices, non implantable medical applications and backup power.