Conductivity enhancement in K+-ion conducting solid polymer electrolyte [PEG : KNO3] and its application as an electrochemical cell

The solution-cast method was used to prepare new solid polymer electrolytes (SPEs) that conduct potassium ions and are based on polyethylene glycol (PEG) complexed with potassium nitrate (KNO3). This polymer electrolyte system was characterized using different experimental techniques, such as X-ray diffraction (XRD), differential scanning calorimetry (DSC), composition vs. conductivity, temperature vs. conductivity, frequency-dependent conductivity, and dielectric measurements. The degree of crystallinity decreased with increasing salt concentration, according to the X-ray diffraction and DSC patterns of PEG with KNO3 salt. For PEG: KNO3 (80 : 20) composition, an optimum conductivity of 8.24x10(-6) S/cm was recorded at 30 degrees C. Compared with pure PEG, the optimum conducting composition (OCC) conductivity increased by two orders of magnitude. The temperature range of 303 to 333 K was used for the temperature-dependent conductivity experiments. The findings demonstrate that the conductivity obeys the Arrhenius rule and increases as the temperature rises. A dc plateau and a dispersive zone were observed in the conductance spectrum, which also follows Jonscher's power law. It was investigated how temperature and frequency affect the dielectric permittivity. An electrochemical cell with the configuration K/(80PEG : 20KNO(3))/(I-2+C+ electrolyte) was constructed using an 80 : 20 electrolyte system, and its discharge properties were investigated. The cell's open circuit voltage was measured at 2.48 V.