Lithium/iodine primary cells

Li2S204 being the SEI component at the Li anode and the solid discharge product at the carbon cathode. The Li—SOCI2 and Li—SO2 systems have excellent operational characteristics in a temperature range from —40 to 60 °C (SOCI2) or 80 °C (SO2). Typical applications are military, security, transponder, and car electronics. Primary lithium cells have also various medical uses. The lithium—silver—vanadium oxide system finds application in heart defibrillators. The lithium—iodine system with a lithium iodide solid electrolyte is the preferred pacemaker cell. 

Primary lithium cells compare favorably with cells with aqueous electrolytes because of their very good shelf life in other words, very low self-discharge. The best shelf life is characteristic for lithium iodine cells, in which the capacity loss under storage for 10 years at the temperature of 40°C does not exceed 10% The guaranteed shelf life (under due conditions) of lithium cells with other electrochemical systems is... 

The requirements for a heart pacemaker power supply are quite different (see Table 10.3). A primary cell will suffice and it need only have a power output of a few microwatts (jliW) but this must be supplied continuously for several years without maintenance and with absolute reliability. It must also be compatible with the body and operate at 37.4°C. Lithium/iodine cells are presently used for this application. 

These researches opened the door to the fabrication and commercialization of varieties of primary hthium batteries since the late l%0s nonaqueous hthium cells, especially the 3-V primary systems, have been developed. These systems include lithium-sulfur dioxide (Li//S02) cehs, lithium-polycarbon monofluoride (Li//(CF t) ) cells introduced by Matsuschita in 1973, lithium-manganese oxide (Li//Mn02) cells commercialized by Sanyo in 1975, lithium-copper oxide (Li//CuO) cells, lithium-iodine (Li//(P2VP)1J cells. During the same period, molten salt systems (LiCl-KCl eutecticum) using a Li-Al alloy anode and a FeS cathode were introduced [1]. The lithium-iodine battery has been used to power more than four million cardiac pacemakers since its introduction in 1972. During this time the lithium-iodine system has established a record of reliability and performance unsurpassed by any other electrochemical power source [18]. 

From the first pacemaker implant in 1958 by Dr Ake Senning surgeon at the Karolinska Hospital in Stockholm, numerous engineering developments have faced challenges in battery power. In 1972, a primary lithium-iodine battery replacing the mercury-zinc cells greatly extended the cardiac pacemaker life (about 10 years). More details on the history of this battery can be found in ref. 

The semiconductive properties and tunnel structure of sulfide and transition-metal oxides led to the use of these materials in lithium power sources (Table 2.5). Several lithium-based chemistries were successfully applied to replace the prior system Zn/AgO and later the lithium-iodine batteries in implantable medical devices [59-61]. For example, Li//CuO, Li//V205, Li//CF and more recently Li// Ag2V40ii couples have been adopted to power cardiac pacemakers requiring less that 200 pW [62,63]. The lithium/carbon monofluoride (Li//CFJ primary cells are very attractive in several applications because of the double energy density with respect to the state-of-the-art LiZ/MnOa primary batteries (theoretically 2203 against 847 Wh kg ). 

Early publications describe rechargeable batteries made from iodine doped PT combined with zinc or lithium electrodes for the construction of primary and secondary electrochemical cells PT samples has been named to be prepared chemically or -leading to better performances - electrochemically [76-78]. Further studies have confirmed high voltage and good energy density of PT in electrochemical cells, but on the other hand the self-discharging properties as a serious problem for the technical application of this material was also named [79-83]. Battery assemblies with PT as... 

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