Potentials lithium alloys

There are some other matters that should be considered when comparing metallic lithium alloys with the lithium-carbons. The specific volume of some of the metallic alloys can be considerably lower than that of the carbonaceous materials. As will be seen later, it is possible by selection among the metallic materials to find good kinetics and electrode potentials that are sufficiently far from that of pure lithium for there to be a much lower possibility of the potentially dangerous forma-... 

A series of experiments have been undertaken to evaluate the relevant thermodynamic properties of a number of binary lithium alloy systems. The early work was directed towards determination of their behavior at about 400 °C because of interest in their potential use as components in molten salt batteries operating in that general temperature range. Data for a number of binary lithium alloy systems at about 400 °C are presented in Table 1. These were mostly obtained by the use of an experimental arrangement employing the LiCl-KCl eutectic molten salt as a lithiumconducting electrolyte. 

Table 1. Plateau potentials and composition ranges of some binary lithium alloys Li v.M at400°C.

In order to achieve appreciable macro Figure 12. Plateau potentials of seven lithium alloy scopic current densities while maintaining systems at ambient temperature 42J. 

The physical properties of lithium metal were given in Table 4.4. Despite its obvious attractions as an electrode material, there are severe practical problems associated with its use in liquid form at high temperatures. These are mainly related to the corrosion of supporting materials and containers, pressure build-up and the consequent safety implications. Such difficulties were experienced in the early development of lithium high temperature cells and led to the replacement of pure lithium by lithium alloys, which despite their lower thermodynamic potential remained solid at the temperature of operation and were thus much easier to use. 

Lithium insertion negative electrodes — (i) Some transition-metal oxides or chalcogenides insert Li ion reversibly at low redox potentials, for example, TiC>2, LL I iOy, M0S2, M0O2. (ii) Lithium alloys - in this case lithium ions, react with other elements polarized to low potentials to reversibly form Li alloys. The reaction usually proceeds reversibly according to the... 

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