Dielectric spectra of LiTFSI - doped chitosan/PEO blends

Solid-polymer-blend electrolyte consisting of chitosan and polyethylene oxide (PEO) in a 1:1 weight ratio and doped with lithium trifluoromethanesulfonimide (LiTFSI) salt was prepared by solution cast technique. The highest conducting film with conductivity value of 1.40 x 10(-6) S cm(-1) at room temperature consists of 30 wt% LiTFSI. The temperature dependence for the highest conducting film obeyed Arrhenius relationship. From loss tangent frequency plots at different temperatures, the frequency f(max) at which the plot is a maximum was obtained. From this, ln f(max) vs 10(3)/T was plotted. The activation energy value obtained from the log sigma vs 10(3)/T plot and ln f(max) vs 10(3)/T plot is about the same, suggesting that the processes of conductivity and relaxation for the charge carriers are the same.