Primary lithium cells

The first electrolytes used for primary lithium cells [47, 48] were based on lith-... 

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. 

The properties of lithium metal were described in Chapter 4, where particular note was made of its high specific capacity and electrode potential. However, because of its highly electropositive nature, it is thermodynamically unstable in contact with a wide variety of reducible materials. In particular, lithium reacts with components of most electrolytes to form a passivating layer. Film formation of this type ensures long shelf life for primary lithium cells, but causes severe problems when the electrode is cycled in a secondary cell. 

Besides the electrical and thermal aspects, carbon conductive additives influence the mechanical properties of the electrodes. In particular, due to its compressibility, graphite improves the electrode density and mechanical stability. The generally lower DBPA of graphite is the reason for the lower amount of binder material necessary to achieve a suitable mechanical stability of the electrode. Further, a more facile spreadability of graphitic filaments in the electrode mass is reported for primary lithium cells.92... 

The intercalation process on the anode side takes place in stages as more and more lithium enters the crystal lattice. A typical electrolyte in lithium-ion cells contains ethylene carbonate and a mixture of aliphatic carbonates such as methyl carbonate, and ethyl methyl carbonate, along with 1M LiPF6 salt. The propylene carbonate containing electrolyte, used in primary lithium cells, could... 

Recently, fluorinated fullerenes, e. g. CgoFao. were proposed as an active material in primary lithium cells. In a mixture with graphite, discharge capacities (Li+ -intercalation and LiF formation) of 560 Ah/kg were reported [231]. 

In all primary lithium cells, the negative electrode is made of metallic lithium. Thus, different types of lithium cells differ in the positive electrode material and in the type of electrolyte. A variety of oxidant materials was offered as the active material of the positive electrode. These included different oxides, sulfides, selenides, oxysulfides, oxychlorides, and some other substances perfluorinated carbon and sulfur. However, only a small number of electrochemical systems in the cells actually reached the industrial production stage. The electrochemical systems of the cells produced industrially are given in Table 11.1. This Table also presents the values of open circuit voltage (OCV) of these cells and the theoretical values of their energy density. 

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