Excellent electrocaloric performance achieved by the high-entropy strategy.

• High-entropy strategy are proposed to design excellent electrocaloric materials. • The diverse local polar state enhances the macroscopic polarization of PT- x HE. • Dynamics transition of polar nanoregions dominate the mechanism of ECE in PT- x HE. • Optimal Δ T of 1.38 K achieved in PT-0.725HE. • Optimal T span of 116 K achieved in PT-0.775HE. Electrocaloric effect (ECE) materials have garnered significant interest for their potential in creating more portable, compact cooling solutions and reducing greenhouse gas emissions. Enhancing both the temperature change Δ T and the temperature span T span of ECE materials remains a formidable challenge. The diverse and flexible local polarization in the high-entropy ferroelectric materials hold promise for addressing this issue. A series of high-entropy ferroelectric ceramics with composition (1- x)PbTiO 3 - x Pb(Mg 0.2 Zn 0.2 Nb 0.2 Ta 0.2 W 0.2)O 3 has been synthesized using a solid-state reaction. As x increases, the crystal structure transitions towards a cubic phase, and the freezing temperature T f decreases from 92 to 47 °C. There is a notable reduction in the coercive field, and the polarization reaches the maximum value of 32.07 μC/cm2 at x = 0.75. Utilizing the direct method, the samples with x = 0.725 and x = 0.75 achieve an optimal Δ T of 0.35 K and T span of 123 K at an electric field of 20 kV/cm, respectively. The Δ T and T span of the sample with x = 0.75 observed by the indirect method surpass 1 K and 100 K, respectively, at an electric field of 55 kV/cm. This study highlights the potential of employing a high-entropy approach to achieve superior ECE performance, paving the way for the development of advanced cooling technologies. [ABSTRACT FROM AUTHOR]