Figure 5 shows microstructures of selected SPEs in various blending systems .Results in SEM
are quite congruent with its corresponding variation in ionic conductivity and activation energy. SEM
has been suggested that morphological effects are responsible for increase in conductivity [14]. There
are small craters are formed on pure PLA and PLA-EC and this is due to the rapid evaporation of THF
solvent during the preparation of the thin film [15]. Pure PLA shows normal porous surface with
uniform small pore size. When the film is mixed with 20 wt % of LiClO
4,
it appears become swollen as
shows in figure 6(c). The addition of LiClO
4
tends to generates more compact and phase-separated
matrix of polymer electrolyte. It also can be observed by comparing figure 6(b) that the pore size