Composite polymer electrolytes with improved lithium metal electrode interfacial properties: I. Electrochemical properties of dry PEO-LiX systems, Appetecchi, Giovanni Battista, Croce F., Dautzenberg G., Mastragostino M., Ronci F., Scrosati B., Soavi F., Zanelli A., Alessandrini F., and Prosini P.P. , Journal of the Electrochemical Society, Volume 145, Number 12, p.4126-4132, (1998)