IONIC CONTACT EQUILIBRIA IN SOLIDS - IMPLICATIONS FOR BATTERIES AND SENSORS

We have been investigating the relevance of ionic space charge effects at surfaces and interfaces in multiphase and polycrystalline materials from both a theoretical and an experimental point of view. A brief review is given, which also includes the behaviour of the electronic minority species, as well as the qualitatively different situation in micro-sized systems. A major part is devoted to the implications with respect to batteries and sensors: i) enhancement of the ionic conductivity of solid battery electrolytes due to internal interfaces; ii) impact of ionic profiles on the phase boundary reactions particularly in e.m.f. and conductivity sensors; iii) formulation of a new sensor principle.