Lithium in W18O49: synthesis and characterization of novel phases

Abstract

Electrochemical lithium insertion into W₁₈O₄₉ has allowed the determination of the existence of a range of intercalated phases, Li_xW₁₈O₄₉. For x < 22 the phases form through an intercalation reaction and four single-phase regions are detected: x= 0–2.6, 3.4–10, 11–15, 15.5–22. In the last of these composition ranges and by reaction with n-butyllithium, a new phase, Li₁₇W₁₈O₄₉, can be isolated that has a multiple cell, with respect to the starting phase. By following this chemical route, the maximum lithium content corresponds to Li₄₀W₁₈O₄₉. Electrochemical experiments showed that lithium is not reversibly intercalated in this last phase.