All laptop computers have lithium-ion batteries.
A lithium-ion battery is a type of rechargeable battery in which lithium ions move from the anode to the cathode when charging and from cathode to anode during discharge. Lithium ions are very light compared to other metal elements, with one atom having only about twice as much mass as one electron (see table below). This low weight is primarily why they make such good batteries for devices like laptops and cellphones. But their lower weight also makes them prone to exploding if not properly handled.