CharacteristicsLithium is the lightest of metals and it floats on water. It also has the greatest electrochemical potential which makes it one of the most reactive of metals. These properties give Lithium the potential to achieve very high energy and power densities permitting batteries with very long useful life and small cell packages. Because Lithium reacts violently with water, as well as nitrogen in air, this requires sealed cells. High-rate Llithium cells build up temperature and pressure if they are short circuited or abused. Thus, the cell design needs to include safety vents, which release the pressure or rupture to prevent uncontrolled explosion. Typical chemistries are Lithium Manganese dioxide, Llithium Sulphur dioxide, Lithium Thionyl Chloride (see below) and Lithium Oxygen (see below) but other variants are available.Available cell voltages range between 3 and 4 VoltsCell packaging includes coin cell and cylindrical packages.Thin film cells based on ceramic or flexible substrates are also available. AdvantagesHigh energy density, double that of premium alkaline batteriesLow weight 
High cell voltage
Flat discharge characteristicLow self dischargeVery long shelf lifeVery long operating life (15 to 20 years for lithium thionyl chloride)Wide operating temperature range ( -60 ° C to +85 ° C for lithium sulfur dioxide)Excellent durabilitySmall cell size ShortcomingsHigh cost ApplicationsComputer memory protectionMedical implantsHeart pacemakersDefibrillatorsUtility metersWatches