Li-ion battery

**Lithium-ion batteries** are widely used in devices such as cell phones, laptops, iPods and PDAs because of their efficiency as rechargeable batteries. The electrodes in a lithium-ion battery are typically made of lithium or lithium cobalt oxide and carbon. Lithium is a highly reactive element that enables a significant amount of energy to be stored in its atomic bonds. During charging, lithium ions move through the electrolyte from the positive electrode (typically lithium cobalt oxide) to the negative electrode (carbon), where they attach to the carbon structure. During discharge, the lithium ions move back from the carbon to the lithium oxide at the positive electrode, releasing energy. This ion movement occurs at a relatively high voltage. Despite their advantages, lithium-ion batteries have a limited lifespan, typically lasting only two to three years, even if they are left unused.