A radio frequency identification (RFID) device provided on a thin-film battery. A system includes the RFID device in communication with a remote radio frequency (RF) transmitter and/or receiver. In some embodiments, the RFID device of the system includes a flexible substrate, a thin-film battery deposited on the flexible substrate, an electronic circuit placed on the battery and coupled to the battery to provide power, and a Radio Frequency (RF) antenna connected to the electronic circuit. In some embodiments, the battery of the RFID device is a rechargeable battery, and the battery is recharged when energy is transmitted from the remote device. Another aspect of the invention provides a system for making an RFID device.