The influence of the supercritical carbon dioxide (scCO2) on ionic conductivity for polyether electrolytes based on oligo(oxyethylene glycol) methacrylate with lithium triflate, LiCF3SO3, has been investigated. In particular, the present research is a first attempt to improve an ion transport behavior of the polyether electrolytes using scCO2 treatment technique. Consequently, the ionic conductivity of scCO2 treated samples at room temperature was more than ten times elevated by the scCO2 treatment under the condition of 10 MPa and 40°C. From the Raman spectroscopy, decrease of aggregate ions and increase of free ions for the scCO2 treated samples have been observed.