Electrochemical measurement of transference numbers in polymer electrolytes

Electrochemical methods for the determination of transference numbers in polymer electrolytes are considered and a new technique which overcomes some of the problems associated with other methods in current use is described. Results are given of measurements of the transference numbers of lithium and trifluoromethanesulphonate ions in poly(ethylene oxide) at 90°C. A mean value of 0.46 ± 0.02 is reported for lithium.