Electric Dipoles and Ionic Conductivity in a Na+ Glass Electrolyte

Glass, unlike a crystalline solid, contains atoms and molecules that do not occupy fixed positions. A glass that contains molecules that attract one another can age with time. We report such a glass that contains A(2)O and (OA)(-) electric dipoles (A = Li or Na). At a temperature T < 1.2T(g) approximate to 110 degrees C (T-g is the glass transition temperature) the electric dipoles coalesce with time into clusters within which, unlike in ice, some dipoles condense into ferroelectric, negatively charged molecules locally charge-compensated by weakly attracted A(+) ions. In an applied electric field, the dipoles are oriented and, over time depending on the T < 110 degrees C, are aligned parallel to the field axis to yield a solid A+ electrolyte with an ionic conductivity si > 10(-2) S cm(-1) and a huge dielectric constant that makes it suitable for many applications, including safe rechargeable batteries of high energy density and long cycle life. (C) The Author(s) 2016. Published by ECS.