Conductivity data for composite gel polymer electrolytes containing different weight ratios of
SiO2 are presented in Figure 4. The ionic conductivity decreases with the addition of SiO
2
loading
beyond 6 wt%. It is shown that ionic conductivity of polymer electrolyte has reached the highest value
of 1.29 x 10
-5
S cm
-1
with 2 wt % SiO2 in PLA-EC-LiClO4.
However, after this weight percent, the
ionic conductivity of polymer electrolytes did not increases with increase of SiO 2
.It started to fall once
the optimum concentration of SiO2
(2 wt %)
is reached.