A type of rechargeable cell in which the anode is carbon and the cathode is a metal oxide (e.g. cobalt(IV) oxide, CoO₂). The electrolyte is a lithium salt such as the borate (LiBO₄) or chlorate (LiClO₄) in an organic solvent. The action of the cell depends on movement of Li ions between anode and cathode with oxidation of the cobalt ions during charging and reduction during discharge. Lithium-ion batteries are light and have a low self-discharge rate, although the capacity does deteriorate with age. They are extensively used in mobile phones, laptops, camcorders, and similar devices, as well as electric cars. See also lithium battery.