To have more understanding of ionic conductivity of polymer electrolyte, further investigate on
the characteristic of salt towards PLA is shown. The graph above shows the different component of
polymer electrolyte with their highest ionic conductivities. From the graph, it can be seen that the
ionic conductivity when added EC is increases slightly only while for PLA+salt has show t he
increment of ionic conductivity dramatically due to salt can increase in the number of free mobile ions
in polymer PLA[11]. The associated increase in the segmental flexibility of polymer chains would
contribute to the conductivity enhancement. However, as shown in the graph, the conductivity
enhancement is little compared with mixed with salt one. Thus, salt is main factor for the ionic
conductivity in polymer electrolyte.