X-ray photoelectron spectroscopy studies on PEOnMBr2 (M = Co, Ni, Zn) solid electrolytes

Abstract

PEOnMBr2 (M = Co, Ni, Zn) electrolytes were prepared at room temperature with values of n ranging from 128 to 8. X-ray photoelectron spectroscopy studies for each electrolyte system indicate a characteristic interaction of the CH2CH2Ochain of PEO with the divalent cations. While in PEO there is only one kind of carbon, these interactions have led to the formation of inequivalent carbons in all three electrolyte systems with increased salt concentration. Strongest cation interaction is identified for all systems at a salt concentration corresponding to n ≅ 16. Whereas the cations are found to change their coordination with varying salt concentration, the anions of each system are found to have nearly unchanged coordination. These results reveal the PEOn MBr2 systems with M = Co, Ni and Zn as complexes formed by the ether oxygen of PEO and each cation and an effective cross-linking between the CH2CH2O chain and the anion of the salt. © 1995.