Solid state batteries are a type of energy storage technology that uses solid materials for both the electrolyte and the electrodes. Unlike traditional lithium-ion batteries, which use liquid electrolytes, solid state batteries can offer higher energy density, improved safety, and longer life cycles. This makes them a promising option for applications in electric vehicles and portable electronics. The solid electrolyte in these batteries can reduce the risk of leaks and fires, common issues with liquid electrolytes. Companies like Toyota and QuantumScape are actively researching and developing solid state battery technology to enhance performance and reliability in future energy solutions.