ELI5: Explain Like I'm 5

lithium ion battery

A lithium ion battery is a type of battery that stores energy so it can be used later. They are used in lots of things we use every day, like phones, laptops, and cars. Inside a lithium ion battery are lots of small cells. The cells are filled with chemicals called lithium ions which have electrical energy. When the battery is put into something like your phone and you plug it into the wall, the lithium ions move around in the cells and release energy. That is what powers your phone or device. When the battery runs out of energy, you just plug it into the wall again and the lithium ions move back inside and store energy.