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Title: Physical properties of Li ion conducting polyphosphazene based polymer electrolytes

We report a systematic study of the transport properties and the underlying physical chemistry of some polyphosphazene (PPhz)-based polymer electrolytes. We synthesized MEEP and variants which employed mixed combinations of different length oxyethylene side-chains. We compare the conductivity and ion-ion interactions in polymer electrolytes obtained with lithium triflate and lithium bis(trifluoromethanesulfonyl)imide (TFSI) salts added to the polymer. The combination of the lithium imide salt and MEEP yields a maximum conductivity of 8 x 10{sup -5} {Omega}{sup -1} cm{sup -1} at room temperature at a salt loading of 8 monomers per lithium. In one of the mixed side-chain variations, a maximum conductivity of 2 x 10{sup -4} {Omega}{sup -1} cm{sup -1} was measured at the same molar ratio. Raman spectral analysis shows some ion aggregation and some polymer - ion interactions in the PPhz-LiTFSI case but much less than observed with Li CF{sub 3}SO{sub 3}. A sharp increase in the Tg as salt is added corresponds to concentrations above which the conductivity significantly decreases and ion associations appear.
Authors:
; ; ; ;
Publication Date:
OSTI Identifier:
431164
Report Number(s):
LA-UR--96-3874; CONF-961040--16
ON: DE97002365; TRN: 97:001021
DOE Contract Number:
W-7405-ENG-36
Resource Type:
Conference
Resource Relation:
Conference: 190. meeting of the Electrochemical Society and technical exhibition, San Antonio, TX (United States), 6-11 Oct 1996; Other Information: PBD: 1996
Research Org:
Los Alamos National Lab., NM (United States)
Sponsoring Org:
USDOE Assistant Secretary for Energy Efficiency and Renewable Energy, Washington, DC (United States)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ELECTROLYTES; LITHIUM COMPOUNDS; PHYSICAL PROPERTIES; POLYMERS; SALTS; PHOSPHORUS COMPOUNDS; IONIC CONDUCTIVITY; TEMPERATURE DEPENDENCE