Rechargeable batteries that use lithium ion technology to store energy are known as lithium batteries. Due to their high energy density, extended life, and ability to function in a variety of temperatures, lithium batteries are widely utilised in a variety of commercial applications, including portable devices, electric cars, and solar energy systems. Compared to conventional lead-acid batteries, lithium batteries are lighter, have a better energy density, and have a longer cycle life. They cost more, though, and special charging and protection circuits are needed to make sure they operate safely.