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 γ‐butyrolactone (γ‐BL) or γ‐butyrolactone/dimethoxyethane mixture (γ‐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 × 10−4S/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.