Publisher Summary There are many types of lithium cell either under commercial consideration or being commercially produced. Lithium-based batteries are quickly entering mainstream electronic designs, particularly in consumer, portable equipment and non-volatile memory back-up applications where small size, long life and low cost are the primary requirements. The practicality of lithium is being greatly enhanced by the current progress in CMOS technology. Indeed, lithium batteries can easily provide standby power for the current crop of 'pure' CMOS devices, which operate at nanoampere current levels. As lowpower CMOS device technology advances— gaining a greater share of semiconductor applications along the way—lithium battery use undoubtedly expands to serve the new areas. The electrochemical potential of lithium-based power sources is known for a long time. Advances in materials processing, materials handling and non-aqueous electrolytes have enabled manufacturers to reduce the potential to practical cell hardware and demonstrate the benefits that were theoretically possible. Three principal types of lithium organic electrolyte battery are currently available; the lithium-thionylchloride system, the lithium-vanadium pentoxide system and the lithium-sulphur dioxide system; these batteries have high-rate capabilities.