A lithium-ion battery has a lithium-based cathode and carbon/graphite anode in a lithium-based solvent acting as the electrolyte. As the battery charges and discharges, lithium ions — atoms with a positive charge — rather than electrons move back and forth between the anode and cathode. The name, in this case, comes from the process and not the material used in the anode or cathode. The lithium-ion batteries in laptops have a cathode made from a lithium-cobalt oxide, and it is this material that causes the thermal overrun in rare cases. Lithium-iron batteries, on the other hand, get their name from the material and not the process, using a lithium iron phosphate for the cathode. These batteries are also sometimes referred to by the lithium iron phosphate molecular formula: LiFePO4. A lithium-iron battery offers less performance than the lithium-cobalt type, especially when both are new; however, the lithium-iron battery is more chemically stable and less sensitive to temperature extremes.