Upper bounds in electrocaloric cooling

摘要

Relaxor ferroelectrics are promsing in EC cooling devices due to a new upper bound of the electrocaloric (EC) effect combined with a corresponding novel figure of merit of EC materials performance. In general, the performance of EC coolers is limited either by the thermal time constants of heat switches or by the heat transfer coefficient to the gaseous or liquid heat transfer agent of active EC regenerators. Cooling power densities of a few W/cm2 are achievable at cycle times of 100 ms.