Effect of the doping method on the sintering characteristics of Gadolinium-doped Ceria

Abstract

Ce0.8Gd0.2O2-d (GDC) is considered one of the most promising electrolyte for intermediate temperature solid oxide fuel cell (IT-SOFC). The reduction of the sintering temperature is one of the most important challenge for the production of fully dense electrolyte. The sintering behaviour of a ceramic body is strongly related to the morphological characteristics of the initial powders and can be affected by the presence of a sintering aid. The latter can be added to the main phase using several methods, ball milling and precipitation being the most generally used. The paper aims to study the influence of the doping method and of the morphology of the dopant on the sintering characteristics of GDC. GDC powders with different specific surface area were doped with 3mol% CuO via ball milling and via nitrate salt and their sintering process followed by dilatometric measurements. The results indicate that the sintering is strongly dependent on the ratio between the specific surface area of pure GDC and CuO. Moreover, the morphology of the dopant greatly affects the sintering rate. Unexpectedly, ball milling was found to be the most effective doping method for CuO-doped GDC leading to a dense electrolyte at temperature as low as 900?