The synthesis and properties of a new type of polymer electrolyte, formed by blending poly(ethylene oxide), PEO, with lithium 4,5-dicyano-1,2,3-triazolate salt, are reported and discussed. The results show that this electrolyte has a wider temperature range of high conductivity and a higher lithium transference number than those of other, common PEO-based electrolyte membranes. (C) 2003 The Electrochemical Society.