An interface ionic transfer detection method called the Doppler broadening S parameter of positron annihilation spectroscopy (PAS) is used to study polysiloxane solid electrolytes with ethylene oxide (EO) side chains and carbonate liquid electrolytes. First, the solid polymer electrolytes are modified to enhance contact with an acrylate, and an increase in the lengths of the EO chains is shown to decrease the resistance of the transition interface layer on a pristine electrode surface. Second, a study of ionic transfer on the electrode surface after electrochemical reactions showed that the solid polymer electrolytes have a greater effect on the interface transition layers than the carbonate liquid electrolytes. In addition, the detection technique revealed a continuous-phase interface containing a chemical membrane formed from carbonate liquid electrolytes by electrochemical reactions; the ionic transfer enhancement due to this membrane is examined by this new detecting methodology.