A solid state battery is a type of battery technology that uses a solid electrolyte instead of a liquid or gel electrolyte found in traditional lithium-ion batteries. This solid electrolyte can enhance safety by reducing the risk of leaks and fires, while also potentially increasing energy density, which means more energy can be stored in a smaller space. These batteries are considered a promising advancement for various applications, including electric vehicles and portable electronics. Companies and researchers are actively working to improve the performance and reduce the manufacturing costs of solid state batteries, aiming to make them a viable alternative to conventional battery technologies like lithium-ion batteries.