High Energy Storage Efficiency and Large Electrocaloric Effect in Lead-Free BaTi0.89Sn0.11O3 Ceramic
Abstract
Lead-free BaTi0.89Sn0.11O3 (BTSn) ceramic was elaborated via a solid-state reaction method and its dielectric, ferroelectric, energy storage, electromechanical as well as electrocaloric properties were investigated at 25 kV/cm. Pure perovskite structure was confirmed by X-ray diffraction analysis. The maximum of the dielectric constant was found to be 17390 at 41 C. The enhanced total energy density, the recovered energy density, and the energy storage efficiency of 92.7 mJ/cm3, 84.4 mJ/cm3, and 91.04%, respectively, were observed at 60 C, whereas the highest storage efficiency of 95.87 % was obtained at 100 C. At room temperature, the electromechanical strain and the large-signal piezoelectric coefficient reached a maximum of 0.07 % and 280 pm/V. The large electrocaloric effect of 0.71 K and the electrocaloric responsivity of 0.28. 10-6 K.mm/kV at 49 C under 25 kV/cm were indirectly calculated via Maxwell relation from the ferroelectric polarization P (T, E) that was determined from the P-E hysteresis loops. By exploiting the Landau-Ginzburg-Devonshire (LGD) phenomenological theory, the electrocaloric response was estimated to be of 0.61 K at 50 C under 25 kV/cm. We conclude that BTSn lead-free ceramic is a promising candidate for potential applications in high-efficiency energy storage devices and solid-state refrigeration technology.