The first lithium zeolitic inorganic–organic polymer electrolyte based on PEG600, Li 2PdCl 4 and Li 3Fe(CN) 6: part I, synthesis and vibrational studies

Abstract

The synthesis of Li 2PdCl 4 and Li 3Fe(CN) 6 precursors, and the preparation of the first lithium Z-IOPE material obtained by reacting these precursors with poly(ethylene glycol)600 (PEG600) is reported. This new material has been obtained through a sol⇒gel and gel⇒plastic transition. FIR and MIR spectroscopy studies, Raman laser and UV–vis investigations and detailed compositional data allowed us to propose a structural hypothesis and to detect the interactions between ions and the coordinating segments of the host network. It has been concluded that: (1) this compound is a mixed inorganic–organic network in which clusters formed by palladium and iron complexes are bonded together by PEG bridges; (2) the conformation of polyether chains in the bulk material is of the TGT (T= trans, G= gauche) type. The conductivity of the proposed [Fe xPd y(CN) zCl v(C 2nH 4n+2O n+1)Li l] is ≈5.3×10 −5 S cm −1 at 35.1 °C.