Lithium iron disulphide cells

Table 9.19 Characteristics of lithium-iron disulphide cells ...

Figure 27.12 Typical LAN (lithium-iron disulphide)cell construction...

Eveready have announced their intention to produce AA type (IECR6) high rate cells for photographic use. Lithium—iron disulphide cells have also been used in paging applications. 

Fig. 9.25 Cross-section of 0.5 A, 28 V lithium-iron disulphide 60 minute thermal batlery. The battery contains 15 active cells and has a total volume of 400 cm3. (By courtesy of Sandia National Laboratories.)...

The lithium-iron disulphide electrochemistry is more straightforward than that of the calcium chromate cell. The overall reaction is ... 

Another advantage to the lithium-iron disulphide system is the absence of high-melting salt phases such as CaCL-KCl. The cell can thus operate close to 352°C. While calcium-calcium chromate may be used with homogeneous electrol5rte-depolarizer blends, iron disulphide must be separated from the anode by a distinct electrolyte layer. Otherwise, the iron disulphide, which is a fairly good conductor, will be electronically shorted to the anode. 

Most experience has been with molten lithium anode batteries where the lithium is mechanically retained. Figure 27.12 shows one version of a lithium-iron disulphide thermal battery cell. The design uses a heat pellet, but heat paper versions are also feasible. 

Lithium-iron disulphide cylindrical cells have proven to be commercially successful. Thus the... 

The commercially most important voltage compatible lithium primary cell uses iron disulphide, FeS2, as cathode. The overall cell reaction may be written as... 

Two companies (Eveready and venture Technology) have been involved in the development of these cells. The venture Technology AAA type bobbin cell introduced in 1982 has a stainless steel can with lithium foil in contact with the inner surface. The positive electrode is a composite of iron disulphide (FCS2), graphite and PTFE binder on an aluminium grid. The separator is porous polypropylene and the electrolyte a solution of lithium perchlorate in a 1 1 v/v propylene carbonate 1 2 dimethoxyethane mixture. 

Since lithium metal is molten at thermal battery discharge temperatures, it is retained on high surface area metals by immersion of the metal matrix in molten lithium to form anodes. Often this structure is contained within a metal cup to prevent leakage during cell operation. Another method is the fabrication of lithium alloy anodes, such as lithium—boron, lithium—aluminium and lithium—silicon, which are solid at battery discharge temperatures and thus offer the possibility of simpler construction. However, the lithium alloys are more difficult to fabricate than the metal matrix anodes and do not achieve this same peak current density. Most of the lithium anode batteries currently use the lithium chloride—potassium chloride electrolyte and an iron disulphide (FeS2) cathode. 

Cells using lithium or the lithium-aluminium alloy-iron disulphide system with a lithium chloride-potassium chloride electrolyte have an on-load... 

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