Composite polyether based solid electrolytes. The Lewis acid-base approach
Abstract
The conductivity and phase structure of several composite polyether-alkali metal salt solid electrolytes are analysed and discussed. Species containing Lewis acid centres (AlCl3), Lewis base centres (poly(N,N dimethylacrylamide) as well as those of amphoteric Lewis acid-base character (α-Al2O3) are used as fillers. It is suggested that the competition between the Lewis base ether oxygens in the polyether chains and filler Lewis base centres in the complexation of alkali metal cations leads to the formation of different types of complexes and therefore to the modification of the polymer electrolyte ultrastructure. On the other hand acidic centres on the fillers compete with the Lewis acid metal cations in the formation of complexes with the polyether chain. The final ultrastructure and conductivity of composite electrolytes depends on the equilibrium of these Lewis acid-base reactions.
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