Designed Giant Room-Temperature Electrocaloric Effects in Metal-Free Organic Perovskite [MDABCO](NH4)I3 by Phase–Field Simulations

Modifying energy storage performances of new lead-free system ferroelectric capacitors through interfacial stress

Nowadays, much attention is paid for developing lead-free ceramics, which can be utilized in the refrigeration domain. This communication provides a detailed description of the synthesis and characterization of a lead-free solid solution of BaTi0.91Sn0.09O3. The X-ray diffraction analysis showed that the compound exhibits a single phase of tetragonal symmetry (P4mm (99)). The average crystallite size estimated using Scherrer's technique was found to be 122 nm. The microstructure or surface morphology of the sintered sample was investigated by using scanning electron microscopy. Based on mapping image, the sensitivity and spatial resolution of the different elements in our sample were improved. Analytical and simulation data for the electrocaloric effect in our sample were reported. A good electrocaloric strength (ξ = ΔT/ΔE) of ξ = 0.171 K mm/kV near the ferroelectric-paraelectric phase transition temperature was obtained. These values are very interesting when compared to those for other materials and show the possibility of using such lead-free ceramics for refrigeration domain.

Electrocaloric properties of lead-free ferroelectric ceramic near room temperature

Large energy storage density and big electrocaloric strength in the BiFeO3–BaTiO3 system.

Large energy-storage density and positive electrocaloric effect in xBiFeO3–(1 − x)BaTiO3 relaxor ferroelectric ceramics

The field-induced transition, which is useful for converting between electrical and thermal energy, was induced in artificially designed complementary-metal–oxide–semiconductor-compatible HfO2/ZrO2 nanolaminates. The electrocaloric effect in HfO2/ZrO2 nanolaminates was affected by the stacking order, attributed to differences in the relative fraction of the nonferroelectric monoclinic phase, and by the aspect ratio, reflecting crystallographic similarities to the tetragonal or orthorhombic phase. An adiabatic temperature change of up to 12.25 K was achieved using a HfO2/ZrO2 bilayer sample. Furthermore, as an electrostatic supercapacitor, the energy storage density reached 49.90 J/cm3. 

Xuefan Xie

Papers

Enhanced electrocaloric effect in the Sm and Hf co-doped BaTiO3 ceramics