Lithium alloy anodes structures

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. 

The subject of surface films on electrodes in non-aqueous solutions is mostly important for the field of batteries. The performance of both Li and Li-ion batteries depends strongly on passivation phenomena that relate to surface film formation on both the anodes and the cathodes. Lithium and lithiated carbon anodes reduce all the solvents and salt anions in electrolyte solutions relevant to Li batteries. The products of these surface reactions always contain insoluble Li salts that precipitate on the electrodes as surface films. All charge transfer processes of Li, Li-C, and Li alloy anodes in Li batteries involve the critical step of Li-ion migration through the surface films. Thereby, the composition, structure, morphology, and electrical properties of surface films on Li, Li-C, and Li alloy electrodes were smdied very intensively over the years. In contrast, reversible magnesium electrodes can function only in surface film-free conditions. ... 

Lithium forms structural alloys with both aluminum and magnesium. Mg-Li alloys have the highest strength-to-weight ratio of all structural materials. Li is used as a degasser to scavenge oxygen in the production of steel and of copper. It is also used as the anode (positive terminal) of some batteries. 

I = 7/2-1—> 5/2-F). The materials that can be studied, thanks to the Mossbauer effect of the above-mentioned nuclei, are also varied. Both cathode and anode materials can be examined. Moreover, the electrochemical reactions in which they are involved may vary from intercalation to conversion and/or alloying. Table 28.1 shows some examples. Fe MS provides useful information in the study of insertion cathodes, such as olivine LiFeP04, as well as layered solids structurally related to LiCo02. Fe MS is also useful to analyze anodes consisting of binary or ternary oxides for conversion reactions, or tin intermetallics that react with lithium by alloying processes. In the latter case, a multiisotope approach can be developed, due to the Mossbauer effect of both Fe and Sn nuclei. 

Li X, Qu M, Yu Z (2009) Structural and electrochemical performances of Li4Ti5 cZrxOi2 as anode material for lithium-ion batteries. J Alloys Compd 487 L12-L17... 

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