How highly efficient power electronics transfers high electrocaloric material performance to heat pump systems

Electrocaloric heat pumps for cooling or heating are an emerging emission-free technology, which could replace vapor-compression systems, harmful refrigerants, and mechanical compressors by a solid-state solution with theoretically even higher coefficient of performance. Existing electrocaloric ceramics could reach around 85% of the Carnot-limit, and existing electrocaloric polymers could enable a compact and high power density system. However, the performance of published system demonstrators stays significantly below this performance, partly because of the external electronic charging loss (cyclic charging/discharging of electrocaloric capacitors). This work analyzes how the latest 99.74% ultra-efficient power electronics enables to maintain a high performance even at the system level. A first-principle analysis on material and system parameters also shows the effect of significantly different material properties of ceramics (PMN, PST) and PVDF-based polymers on system parameters. A system benchmark provides insight into system characteristics not covered by material analysis. Graphical abstract