Polymer Electrolytes with Exclusively Cationic Conductivity

The synthesis of exclusively cation conducting polymer electrolytes based on a nylon-l backbone, ethylene-oxide side chains, and attached dibutyl phenolate anions is described. The tendency for ion pair formation appears to be reduced as the conductivity of the sodium-containing compound reaches −2 × 10−6 S-cm−1 at 50°C. 23Na nuclear magnetic resonance measurements demonstrate: i) motional narrowing of the mobile Na+ resonance above the glass transition temperature; ii) mobile Na+ concentrations of ∼75% at 40°C; iii) insensitivity of the linewidth to applied hydrostatic pressure up to 2 kbar. Similaries between these findings, and those in “conventional” polymer-salt electrolytes are discussed.