| Abstract
| - Conductivity and transport properties have been determined for gelled polymer electrolytes of threecompositions: a base PVdF−polymer gel with organic carbonate solvents as plasticizers and LiN(SO2C2F5)2electrolyte, a second polymer electrolyte with 5 mass % 1-ethyl-3-methylimidazolium bisperfluoroethylsulfonylimide (EMI−BETI) added to the base polymer electrolyte, and a third PVdF polymer electrolyte using onlyEMI−BETI as the plasticizer. Conductivities were studied over the temperature range +25 to −40 °C, andfor all three gels, the temperature dependence of the conductivities was found to follow the VTF equation,which is consistent with the free volume model for ion transport. For the gel containing 5 mass % EMI−BETI, transport numbers were determined from +50 to −20 °C and were found to decrease as the temperaturedecreased. Although there are no theoretical models to treat and interpret the temperature dependence oftransport numbers, we found that a modified VTF equation resulted in an excellent fit to the temperaturedependence of the transport number, which is another confirmation of a free volume model for transport inthese gelled polymer electrolytes.
|
