Electric fatigue in functional materials encompasses a set of phenomena, which lead to the degradation of materials with an increasing number of electrical cycles.
Electric cycling leads to both reversible and irreversible currents and polarisations. Ionic and electronic charge carriers interact with each other and with microstructural elements in the bulk as well as at interfaces (grain boundaries and domain walls) and interphases (electrode/electrolyt). This in turn causes local changes in the distribution of electric currents and electric potentials. As a consequence local overloads and material degradation ensues and leads to irreversible loss of material properties.
This material degradation can lead finally to mechanical damage as well as to dissociation reactions. The basic phenomena of electric fatigue are not yet understood on a microscopic level.