Airlines have strict rules about where you can pack your laptop, and lithium-ion batteries are the reason. These batteries, which power everything from phones to electric cars, can pose a fire risk under certain conditions. The danger comes from lithium itself. This lightweight metal is highly reactive, meaning it can quickly undergo chemical reactions. For example, when pure lithium comes into contact with water, it produces heat and releases hydrogen gas, which is extremely flammable. That same reactivity, however, is what makes lithium so useful. In batteries, lithium easily moves between different chemical states, allowing it to store and release energy efficiently. This is why lithium-ion batteries are central to modern technology and the transition to cleaner energy. They are widely used in electric vehicles and are essential for storing power generated by renewable sources like solar panels and wind turbines.…