Giant electrocaloric materials energy efficiency in highly ordered lead scandium tantalate

Abstract

Electrocaloric materials are promising working bodies for caloric-based technologies, suggested as an efficient alternative to the vapor compression systems. However, their materials efficiency defined as the ratio of the exchangeable electrocaloric heat to the work needed to trigger this heat remains unknown. Here, we show by direct measurements of heat and electrical work that a highly ordered bulk lead scandium tantalate can exchange more than a hundred times more electrocaloric heat than the work needed to trigger it. Besides, our material exhibits a maximum adiabatic temperature change of 3.7 K at an electric field of 40 kV cm−1. These features are strong assets in favor of electrocaloric materials for future cooling devices.

Large harvested energy with non-linear pyroelectric modules

“…Therefore, phase transitions should enable more energy to be harvested. The need for large-area cycles in the case of NLPs is very similar to what is required for electrocalorics 9 – 12 , for which multilayer capacitors (MLCs) of PST and poly(vinylidene fluoride)-based terpolymer have recently shown excellent solid-state cooling performances in reversed cycles 13 – 16 . Thus, we identified PST MLCs of interest for the purpose of thermal energy harvesting.…”

Electrocaloric Coolers: A Review

“…Within such a design though, the temperature difference between source and sink cannot exceed the temperature change of the EC effect. [60,61,64] Considering that practical EC materials display rather low EC effects (∆T ad < 5 K), [10,34] the cycle described above is not sufficient for realistic cooling applications, where temperature spans larger than 20 K are required. [65]…”

“…Typical bulk materials reporting large EC effects are ferroelectric perovskite‐like ceramics, such as PbSc 0.5 Ta 0.5 O 3 (PST), (1‐ x )Pb(Mg 1/3 Nb 2/3 )O 3 – x PbTiO 3 (PMN‐100 x PT), PbZr 0.95 Ti 0.05 O 3 (PZT) or BaTiO 3 (BTO). [ 34–39 ] These kind of samples have been already implemented in a few EC coolers. [ 40–43 ]…”

“…Typical bulk materials reporting large EC effects are ferroelectric perovskite-like ceramics, such as PbSc 0.5 Ta 0.5 O 3 (PST), (1-x)Pb(Mg 1/3 Nb 2/3 )O 3 -xPbTiO 3 (PMN-100xPT), PbZr 0.95 Ti 0.05 O 3 (PZT) or BaTiO 3 (BTO). [34][35][36][37][38][39] These kind of samples have been already implemented in a few EC coolers. [40][41][42][43] A solution to decrease the applied voltage is shortening the distance between electrode plates by growing thin films (right object in Figure 1).…”

Large electrocaloric effect with high thermal and electric field cycling stability in solution-processed Y:HfO2 thin films

“…The electrocaloric effect (ECE) is the change in entropy and thereby adiabatic temperature change (DT) caused by the change in the applied electric eld (DE) in polar materials, which can be applied for environment-friendly solid-state refrigeration and cooling applications for electronic devices including micro-devices, household appliances and specialized high-temperature appliances for military and satellite applications. [1][2][3][4] Numerous studies have focussed on developing an environment-friendly ECE material that shows an ECE temperature change sufficient for daily-life applications. 5 High ECE temperature change DT and the ECE strength DT/DE are considered as the main factors in developing a suitable ECE candidate.…”