Lithium-ion batteries are rechargeable batteries that use lithium as one of their active components. They are widely used in electronic devices such as smartphones, laptops, and electric vehicles due to their high energy density, long cycle life, and low self-discharge rate. Research in this area focuses on improving the energy density, safety, and performance of lithium-ion batteries through the development of new materials, manufacturing processes, and battery management systems. Key challenges in this field include increasing the battery's capacity, reducing costs, and addressing safety concerns such as the risk of thermal runaway and fire.