High performance relaxor ferroelectric textured ceramics for electrocaloric refrigeration

Abstract Relaxor ferroelectric ceramics have emerged as promising candidates for electrocaloric cooling systems due to their relatively higher heating and cooling capacities. However, simultaneously achieving high temperature changes (ΔT) and a wide operating temperature range remains a significant challenge, limiting their practical applications. This work proposes a synergistic strategy that involves precise compositional tuning of the BaTiO₃-xKNbO₃ system to customize the rhombohedral-to-cubic phase boundary around room temperature, coupled with engineering grain orientation of the ceramics. Based on this approach, a maximum ΔT of 3.9 K was achieved in <111>c-texture BaTiO₃-KNbO₃ ceramics, outperforming most environmentally friendly ceramics. Notably, the ΔT variation remained within ±10% across a temperature range of 30oC to 80oC, demonstrating a promising material for the design and application of electrocaloric cooling devices. This work provides new insights for the design of ceramics with optimized electrocaloric properties, offering significant potential for improving the efficiency and functionality of next-generation cooling technologies and devices.