Properties of polymer solid electrolytes composed of poly(ethylene carbonate) [PEC], lithium bis(trifluoromethane sulfonimide) [LiTFSI, LiN(CF3SO2)2] and propylene carbonate [PC] as plasticizer have been analyzed using Raman spectroscopy and ac impedance spectroscopy. Including 14 wt% of PC in the PEC based polymer electrolyte with LiTFSI concentration of 0.2 mol per polymer repeat unit, made it possible to increase the ionic conductivity (σ) by one order of magnitude to a practical-use level of 1.3mScm-1 at 20°C. The correlation between • and temperature fits well the Williams-Landel-Ferry equation, so it is considered that ionic conductivity depends on thermal activation of the polymer chains. From the correlation between • and temperature, it is concluded that PC (with greater mobility than the polymer chains) partly solvates with lithium ions, and • is improved by lowering its activation energy.
All Science Journal Classification (ASJC) codes
- Chemical Engineering (miscellaneous)
- Materials Science (miscellaneous)
- Environmental Science(all)
- Polymers and Plastics