  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 {\deg}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 {\deg}C, whereas the highest storage efficiency of 95.87 % was
obtained at 100 {\deg}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 {\deg}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 {\deg}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.

Materials Science