Influence of powders thermal activation process on the production of planar beta-alumina ceramic membranes

ZEBRA batteries (Zero Emission Battery Research Activities) for their high energy and power density are one of the possible solutions to electrical storage for stationary applications. These systems are based on nickel chloride-sodium cells operating at high temperatures (about 270 degrees- 350 degrees C), and rely on a ceramic beta ''-alumina tube or planar membrane as solid electrolyte. The ceramic process needed to produce the membrane electrolyte has a key role in enhancing and adapt the battery performance to the specific requirements for stationary and mobile applications. Minimal variations in composition or processing strongly influence the final properties of the storage device. The aim of this work was to examine in detail the relevant steps needed to obtain ceramic b"-alumina membranes with suitable morphologicalstructural characteristics, from powder synthesis to planar electrolyte forming and sintering. In particular, the reactive sintering processes and the influence of thermal treatments on the chemical-structural properties of the ceramic materials were deeply investigated. It was found that a high temperature calcination is a key step to obtain membranes with suitable mass density, high b''-alumina content and optimum ionic conductivity. (C) 2016 Elsevier B.V. All rights reserved.