DUAL-PHASE SOLID POLYMER ELECTROLYTES PREPARED FROM STYRENE-BUTADIENE COPOLYMER LATICES

A new dual-phase solid polymer electrolyte system has been proposed. In this system, a network of ion pathways is formed in a low-polarity, host polymer matrix. A series of electrolytes were prepared from styrene-butadiene copolymer latices with dissolved lithium salts. Polymer films were formed from these latices, and then impregnated with gamma-butyrolactone (gamma-BL) or gamma-butyrolactone/dimethoxyethane mixture (gamma-BL/DME), giving latex polymer electrolytes. The ionic conductivity of the polymer electrolyte system increased with increasing solvent content, although a distinct percolation threshold was not measured. Ionic conductivity also increased with the use of DME cosolvent, with the highest conductivity being 1.4 X 10(-4) S/cm. Complex impedance diagrams are discussed. The diagrams show significant deviations from the ideal. TEM/SEM observations are consistent with the desired dual-phase morphology.