Influence of sintering temperature on electrocaloric and energy storage properties of sol-gel derived lead-free BaHf0.20Ti0.80O3 ferroelectric ceramics for sustainable energy solutions

• Published in: Materials chemistry and physics 2024-06, Vol.319, p.129374, Article 129374
• Main Authors: Nandan, Revati, Syal, Rajat, Kumar, Sanjeev, Negi, Nainjeet Singh
• Format: Article
• Language: English
• Subjects: BaTiO3-based lead-free ceramics; Dielectric properties; Electrocaloric effect; Energy storage properties; Microstructure evolution
• ISSN: 0254-0584; 1879-3312
• DOI: 10.1016/j.matchemphys.2024.129374

Ferroelectric materials have emerged as intriguing contenders for a variety of applications in the ongoing effort to look for sustainable energy solutions, including energy storage and solid-state cooling systems. In this work, a systematic investigation has been conducted on the microstructural, dielectric, electrocaloric, and energy storage characteristics of sol-gel elaborated BaHf0.20Ti0.80O3 (BHT) ferroelectric ceramics. The structural investigation by Raman and X-ray diffraction indicated that when the sintering temperature increases, the tetragonality of BHT ceramics reduces, and the evolution of the cubic phase increases. The evolution of the microstructure in BHT ceramics is found to be significantly reliant on the sintering temperature. With increasing temperature of sintering, the bulk density of BHT ceramics increases. The improved dielectric and ferroelectric properties were attained in BHT ceramics at higher sintering temperatures. The BHT ceramic sintered at 1350 °C exhibited a maximum electrocaloric temperature change of ΔT ∼0.6 °C with a corresponding efficiency ΔT/ΔE of 0.3 K mm/kV near ambient temperature under a low electric field of 20 kV/cm. The BHT ceramic sintered at 1450 °C exhibited excellent room temperature recoverable energy density of JRec ∼67.84 10−3J/cm3 and high energy storage efficiency of η ∼75.13 % under a low electric field of 20 kV/cm. The highest JRec ∼73.22 10−3J/cm3 with corresponding η of 64.60 % were obtained in BHT ceramic sintered at temperature 1350 °C. These findings broaden the possibility of exploring BHT-based systems as efficient lead-free ferroelectrics for both solid-state refrigeration and energy storage applications. •The microstructural and electrical properties influenced by sintering temperature.•The density and grain size increases with increasing sintering temperature.•Enhanced electrocaloric and energy storage response at higher sintering temperatures.•The maximum ΔT of 0.6 °C was obtained under a low electric field of 20 kV/cm.•The small grain size is useful in achieving improved energy storage density.