Tuning anhydrous proton conduction in single-ion polymers by crystalline ion channels.

The synthesis of high-conductivity solid-state electrolyte materials with eliminated polarization loss is a great challenge. Here we show a promising potential of single-ion block copolymers with crystalline protogenic channels as efficient proton conductors. Through the self-organization of zwitterion, imidazole, and polystyrene sulfonate with controlled dipolar interactions therein, the distance between neighboring proton donors and acceptors in ionic crystals, as well as the dipolar orientation in nanoscale ionic phases was precisely tuned. This allowed a markedly high static dielectric constant comparable to water and fast structural diffusion of protons with a low potential barrier for single-ion polymers. The optimized sample exhibited a high proton diffusion coefficient of 2.4 × 10-6 cm2 s-1 under anhydrous conditions at 90 °C.