elektrodsystem on solid electrolyte ceramic material of zirconium dioxide for probes for electrochemical anvendningar and seen to framstella these

摘要

To improve current loading of the electrodes and thus improve the start-up operation of an electrochemical system which includes a solid electrolyte body, particularly at temperatures in the order of about 300 DEG C., the solid electrolyte body and the electrode layer thereover has an intermediate coating of fully stabilized zirconium dioxide applied; for example partially stabilized zirconium dioxide is fully stabilized in its surface region by yttrium or ytterbium oxide. This intermediate layer, while improving the current carrying capability of electrodes applied thereover, additionally prevents the occurrence of damage to the microstructure of partially stabilized solid electrolyte ceramic, particularly under changeable temperature loading, so that, if the solid electrolyte body essentially entirely consists of partially stabilized ceramic, the additional fully stabilized coating or surface zone can also be provided where the solid electrolyte body does not carry an electrode layer. The fully stabilized coating or layer - which may be a surface zone of the partially stabilized body - can be obtained by coating the partially stabilized body with a stabilization oxide which, in a heat treatment, is then diffused into the surface zone; or an aqueous suspension of about 92 mol-% ZrO2 and 8 mol-% Y2O3 or 8 mol-% Yb2O3 can be applied, by spraying, dipping, or the like; up to 3% (by weight) of sinter-active Al2O3 is preferably added in order to improve sintering activity of the layer, over which, where desired, an electrode layer or a composite cermet electrode layer can be applied.