Cylindrical lithium-ion batteries are divided into three materials: lithium cobalt oxide and lithium manganate. There are three kinds of materials for system batteries with their own advantages, which are widely used in: notebook computers, digital cameras, lighting, toy products, power tools, portable energy and other fields. There are many kinds of cylindrical lithium-ion batteries,such as 18650 cylindrical lithium-ion batteries, 21700 cylindrical lithium-ion batteries, 26650 cylindrical lithium-ion batteries, 32700 cylindrical lithium-ion batteries and so on. Cylindrical lithium-ion batteries are popular among Japanese and Korean lithium-ion battery companies.