A solid polymer electrolytes based on PLA–EC–LiClO4
–SiO2
complexes have been
synthesized successfully by solution casting method. The incorporation of LiClO4
salt, EC plasticizer
and SiO
2
nano filler has led to significantly enhanced ionic conductivities. The composition PLA–EC–
LiClO4
–2 wt %. SiO
2
exhibits the highest room temperature conductivity, with a value of 1.29 x10
−5
S
cm
−1
compared with the conductivity of PLA, 9.46 x 10
-12
S cm
−1
. The ionic conductivity of the
polymer electrolytes increases with increasing the content of salt and shows the salt is main contributor
to ionic conductivity. The increase in conductivity is due to the reduction in crystalline phase upon the
addition of salt, plasticizer and filler as evidenced from the XRD analysis. The intensities of the
crystalline peaks of the XRD pattern decrease and the area below the peaks broadens. All of this may
be related to a possible enhancement in the segmental flexibility of polymeric chains and the
disordered structure of the electrolyte where the lithium ion motion taking place in the amorphous
phase is facilitated compared to the pure PLA sample. An additional increase of ionic conductivity due
to addition of filler SiO2
which can be explained by the availability of extra hopping sites for
migrating ionic species due to the formation of transient H-bonding with O–OH groups at