**7. Application**

More and more uses, with varying demands for energy storage, are finding it difficult to stockpile electricity. Printed batteries are only ever mentioned in the

literature when the energy demand of a thin-film battery application is less than 1 Ah [5]. Since the battery thickness needed to power a gadget may be drastically reduced with thin-film lithium-ion batteries, slimmer portable electronics can be created with them. These power sources could be used in a wide variety of implantable medical devices, including; Implanted Cardioverter Defibrillators (ICD), Cochlear Implants, Implanted Drug Pumps, Implanted Pacemakers etc.

Thin-film batteries are an efficient means of storing the intermittently produced electricity from solar and other renewable energy sources. It is possible to design these batteries with a negligible self-discharge rate, allowing them to be stored for extended periods without suffering a serious loss of energy capacity [80]. When completely charged, these batteries may also provide more consistent energy for a smart electrical grid [81].

Similar in size to a conventional credit card, "smart cards" actually contain a microchip that can be read, written to, authorized or used to process information. These cards are manufactured in fairly severe environments, with temperatures reaching as high as 150°C. At this severe temperature, other batteries could suffer damage because their internal parts could degas or simply malfunction. Thin- film lithium-ion batteries, however, may operate in temperatures ranging from 40 to 150°C [82]. In addition, the durability of thin film lithium-ion batteries may be advantageous in other applications that involve temperatures that the human body cannot withstand [81].

Radiofrequency identification (RFID) tags are employed in logistics and stock management and are frequently included in discussions of the Internet of Things (IoT) [83, 84]. RFID tags have several applications, some of which include authentication, identification and security. Some RFID tags have built-in sensing technologies that can pick up data about their immediate surroundings. With a higher output battery, the RFID tag may be read from greater distances [85]. As these tags become more sophisticated, the battery demands will have to keep up, and thin-film batteries can be incorporated into these tags due to the battery's versatility in terms of size and shape, as well as the ability to power the tag's functions. The disposable applications of RFID technology may be made possible by the low production costs of thin-film batteries [81].

As these tags become more sophisticated, the battery demands will have to keep up, and thin-film batteries can be incorporated into these tags due to the battery's versatility in terms of size and shape, as well as its ability to power the tag's functions.

Batteries for implantable medical devices must be reliable and able to give power for an extended period. These batteries must have a low self-discharge rate while not in use and a high-power rate when it is being used, particularly for usage in an implantable defibrillator [86]. Batteries for implantable medical devices should have a high capacity for charge and discharge cycles so that the devices can go longer between servicing and replacement [87]. The power needs of implantable medical devices are ideally met by thin-film batteries. Since the electrolyte in thin-film batteries is solid rather than liquid, they may be shaped in a wide variety of configurations without the risk of leakage, and it has been found that certain types of thin-film batteries can withstand charging and discharging for up to 50,000 times.

The global applications of thin-film batteries cannot be fully enumerated here. They also find applications in smart cards, touch screens, wireless sensors, laptops, astronomical mirrors, photovoltaic energy generation and storage, RFID tags, implantable devices and many others.
