Effects of CdCl2 concentration on the structural, thermal and ionic conductivity properties of HPMC polymer electrolyte films

The present study illustrates cadmium chloride (CdCl2)-doped hydroxypropyl methylcellulose (HPMC) polymer electrolyte films. Solution cast method is employed to prepare polymer electrolyte samples of HPMC complexed with various concentrations of CdCl2 (1–4 %, wt.%). Structural and thermal studies of these polymer samples were investigated using X-ray diffraction (XRD) and differential scanning calorimetry (DSC). XRD results showed that the amorphous domains of HPMC polymer matrix were increased with increase in CdCl2 salt concentration. DSC results revealed that the presence of CdCl2 in the polymer matrix increases the melting temperature; however, it is observed that the heat of fusion (ΔH f ) is high for pure HPMC films. The variation in the film morphology was examined by scanning electron microscopy (SEM). Direct current (dc) conductivity was measured in the temperature range 313–383 K. The magnitude of electrical conductivity was found to be increased with increasing salt concentration and temperature. The activation energy region data (region I and region II) indicated the dominance of ion-type charge transport in these polymer electrolyte films. HPMC polymer electrolytes with 4 % CdCl2 salt concentration exhibit the least crystallinity and the highest conductivity 1.01 × 10−6 Scm−1 at 313 K.