Thermally-stable high energy storage performances and large electrocaloric effect over a broad temperature span in lead-free BCZT ceramic

Zouhair Hanani (1, 2) , Soukaina Merselmiz (1) , Daoud Mezzane (1) , M'Barek Amjoud (1) , Andraž Bradeško (3) , Brigita Rožič (3) , Mohammed Lahcini (1, 4) , Mimoun El Marssi (5) , Andrey Ragulya (6) , Igor A. Luk'Yanchuk (5, 7) , Zdravko Kutnjak (3) , Mohamed Gouné (2)

1 UCA - Université Cadi Ayyad [Marrakech]
2 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux
3 IJS - Jozef Stefan Institute [Ljubljana]
4 UM6P - Université Mohammed VI Polytechnique [Ben Guerir]
5 LPMC - Laboratoire de Physique de la Matière Condensée - UR UPJV 2081
6 IPMS - I.N. Frantsevich Institute for Problems of Materials Science of NAS of Ukraine
7 Physics Faculty

Ba0.85Ca0.15Zr0.10Ti0.90O3 (BCZT) relaxor ferroelectric ceramics exhibit enhanced energy storage and electrocaloric performances due to their excellent dielectric and ferroelectric properties. In this study, the temperature-dependence of the structural and dielectric properties, as well as the field and temperature-dependence of the energy storage and the electrocaloric properties in BCZT ceramics elaborated at low-temperature hydrothermal processing are investigated. X-ray diffraction and Raman spectroscopy results confirmed the ferroelectric–paraelectric phase transition in the BCZT ceramic. At room temperature and 1 kHz, the dielectric constant and dielectric loss reached 5000 and 0.029, respectively. The BCZT ceramic showed a large recovered energy density (Wrec) of 414.1 mJ cm−3 at 380 K, with an energy efficiency of 78.6%, and high thermal-stability of Wrec of 3.9% in the temperature range of 340–400 K. The electrocaloric effect in BCZT was explored via an indirect approach following the Maxwell relation at 60 kV cm−1. The significant electrocaloric temperature change of 1.479 K at 367 K, a broad temperature span of 87 K, an enhanced refrigerant capacity of 140.33 J kg−1, and a high coefficient of performance of 6.12 obtained at 60 kV cm−1 make BCZT ceramics potentially useful coolant materials in the development of future eco-friendly solid-state refrigeration technology.

Domaines: Matériaux

Zouhair Hanani, Soukaina Merselmiz, Daoud Mezzane, M'Barek Amjoud, Andraž Bradeško, et al.. Thermally-stable high energy storage performances and large electrocaloric effect over a broad temperature span in lead-free BCZT ceramic. RSC Advances, 2020, 10 (51), pp.30746-30755. ⟨10.1039/D0RA06116F⟩. ⟨hal-02981577⟩