  In the present article, we have studied the effect of the salt concentration
(LiPF6) on transport properties and ion dynamics of blend solid polymer
electrolyte (PEO PAN) prepared by solution cast technique. Fourier transform
infrared (FTIR) spectroscopy confirms the presence of microscopic interactions
such as polymer ion and ion ion interaction evidenced by a change in peak area
of anion stretching mode. The fraction of free anions and ion pairs obtained
from the analysis of FTIR implies that both influence the ionic conductivity
with different salt concentration. The complex dielectric permittivity,
dielectric loss, complex conductivity have been analyzed and fitted in the
entire frequency range (1 Hz to 1 MHz) at room temperature. The addition of
salt augments the dielectric constant and shift of relaxation peak in loss
tangent plot toward high frequency indicates a decrease of relaxation time. We
have implemented the Sigma representation sigma double prime vs sigma prime for
solid lithium ion conducting films which provide better insight toward
understating of the dispersion region in Cole Cole plot epsilon double prime vs
epsilon prime in lower frequency window. The dielectric strength, relaxation
time and hopping frequency are in correlation with the conductivity which
reveals the authenticity of results. Finally, the ion transport mechanism was
proposed for getting the better understanding of the ion migration in the
polymer matrix.
