Lithium storage alloys

Figure 1 presents results on the beneficial effect of a new electrolyte solvent on the cycling behavior of the lithium storage alloy Sn2Co. The influence of the adapted electrolyte may become even more clearly by taking a look at the cumulated charge losses (Fig. 22). It should be noted that this new electrolyte component is not able to suppress solvent co-intercalation into graphite [37], emphasizing the above-mentioned different requirements on the electrolyte.

An overview about more than 10 years of R D activities on solid electrolyte interphase (SEI) film forming electrolyte additives and solvents at Graz University of Technology is presented. The different requirements on the electrolyte and on the SEI formation process in the presence of various anode materials (metallic lithium, graphitic carbons, and lithium storage metals/alloys are particularly highlighted. 

SEI FORMATION AND SEI STABILITY ON LITHIUM STORAGE METALS AND ALLOYS... 

Electrolyte effects on the cycling stability of lithium storage metals and alloys indicate the importance of SEI formation in this case, too. Very early measurements suggest that additives such as CO2 do not only improve the cycling stability of metallic lithium [41] and graphitic carbons (see above), but also that of lithium storage metals (Fig. 18), which may be related with the electrical properties of the SEI (Fig. 19) [13]. 

Ichikawa, T., S. Isobe, N. Hanada, and H. Fujii, Lithium nitride for reversible hydrogen storage, /. Alloys Compd., 365,271,2004. 

Tetrahydrofuran is a flammable liquid with a flash point of 6°E and explosive limits ranging from 2% (lower) to 11.8 % (upper). It is incompatible with strong oxidizers and lithium-aluminum alloys. Peroxides may accumulate upon prolonged storage in the air. 

Limthongkul P, Jang Y-I, Dudney NJ, Chiang Y-M (2003) Electrochemically-driven solid-state amorphization in lithium-silicon alloys and implications for lithium storage. Acta Mater 51 1103-1113... 

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