Ultra-high-temperature electrocaloric heat pump

• We simulated the first ultra-high-temperature solid-state heat pump. • The heat pump uses realistic properties of electrocaloric material PbZr 0.52 Ti 0.48 O 3. • It provides heating power of max 113.3 W/kg EC and max COP 2.67 between 630 and 690 K. Nearly a quarter of waste heat is generated at temperatures exceeding 300 °C, yet conventional heat pump technologies remain inefficient in recovering and utilizing heat from such high temperature sources. In this study, we introduce a novel electrocaloric heat pump designed to operate with heat sources and sinks at ultra-high temperatures. The proposed heat pump system incorporates an active electrocaloric regenerator featuring PbZr 0.52 Ti 0.48 O 3 (PZT) epitaxial thin-film multilayers, which exhibit a superior electrocaloric adiabatic temperature change of 11.03 K at 402 °C (675 K), and pressurized helium gas as the working fluid. We conducted a parametric analysis to simulate the performance of the ultra-high-temperature electrocaloric heat pump and identified the optimal conditions for single- and multi-stage configurations. The single-stage setup achieved a maximum heating COP of 7.8 at a 30 K temperature span across the regenerator at a heat source temperature of 660 K. In comparison, the multi-stage configuration yielded the highest heating power 113.3 W/kg EC and a max. COP 2.7 between 630 and 690 K. This study established a foundation for notable advancements in ultra-high-temperature heat pumps by employing electrocaloric energy conversion.