Lithium chemical diffusion coefficients in poly(ethylene oxide)-molybdenum sulfide nanocomposites

The intercalation of poly(ethylene oxide) (PEO) in molybdenum sulfide (MoS2) forms the nanocomposites LixMoS2(PEO)(0.5) and LixMoS2(PEO)(1.0). The lithium ion diffusivity in PEO-containing phases, which depends on both PEO and lithium content, is always higher than in pure MoS2. The maximal observed diffusivity values, but also the strongest dependence on lithium concentration, are observed for LixMoS2(PEO)(0.5), possibly due to their relatively greater freedom for rearrangement. Lithium diffusion activation thermodynamic parameters indicate a mechanism which appears to be mainly governed by PEO conformational changes caused by the trend of the polymer to coordinate lithium ions. (C) 1997 Elsevier Science Ltd. All rights reserved.