Poly(acrylonitrile)–molybdenum disulfide polymer electrolyte nanocomposite

Abstract

The synthesis, characterization and electrochemistry of a novel nanocomposite based on the co-intercalation of lithium and poly(acrylonitrile) (PAN) in molybdenum disulfide [Li_0.6MoS₂(PAN)_1.2·0.5H₂O] is described. The product, obtained chemically by treating LiMoS₂ directly with a colloidal suspension of PAN in benzene, has a lamellar structure with an interlaminar distance of 1.15 nm. Elemental analysis, FT-IR spectra, thermal analysis and ⁷Li MAS-NMR spectra indicate that the polymer is co-intercalated with lithium in the MoS₂ matrix. Lithium can be de-intercalated and intercalated electrochemically from the nanocomposite in the range x = 0.1–0.8. The structure of the interlamellar phase and the state of lithium in the Li_xMoS₂(PAN)_1.2 intercalates are discussed by comparing the behavior of both the potential and the diffusion coefficient with those of the poly(ethylene oxide) (PEO) and diethylamine (DEA) MoS₂ intercalates. Both, the average quasi-equilibrium Li/Li⁺ potential of PAN nanocomposites (2.85 V) and the lithium diffusion coefficient (4.3 × 10⁻¹¹ cm² s⁻¹) at room temperature are encouraging for exploring the use of this nanocomposite as an electrode.