Solid polymer electrolytes based on segmented polysiloxane-modified waterborne polyurethane

Polymer electrolytes were synthesized from polydimethylsiloxane (PDMS) mixed with waterborne polyurethane (WBPU) prepolymers in different weight ratios. ¹H-NMR, differential scanning calorimetry, ac impedance spectroscopy and cyclic voltammogram were used to characterize the their structure, thermal properties, ionic conductivities and electrochemical stability respectively. The results showed that the ionic conductivities of the polymer electrolytes consisted with the adding amount of PDMS, the concentration of lithium salt and the testing temperature. The ionic conductivity of segmented polysiloxane-modified WBPU (w(PDMS)=5% w(WBPU), w(LiTFSI)=20%w(PDMST WBPU)) system reaches an order of 8.11 × 10^-6 S/cm at 30°C and 1.66 × 10^-4 S/cm at 80°C. Cyclic voltammogram indicates that the polymer electrolyte has good electrochemical stability in the working voltage ranging from 2-5.5 V and can be applied to lithium-ion battery.