Influence of aging on electrocaloric effect in Li+ doped BaTiO3 ceramics

Abstract

Aging creates significant changes in the properties of the ferroelectric materials such as dielectric and piezoelectric properties. However, the influence of aging on the electrocaloric effect (ECE) has not yet been investigated. In this work, we investigate the effect of the aging on the ECE in acceptor (Li þ ) doped BaTiO 3 ceramics. We observe that aging induced defect polarization (P D ) reduces the saturation polarization of the doped samples until T c ¼ 115 C. Above that temperature P D loses its effectiveness and material behaves like a fresh sample. Suppression of polarization below T C due to aging effect results in a sharper slope change in the temperature dependence of electrical polarization in aged samples which causes an increase in the electrocaloric temperature change of Li þ doped BaTiO 3 ceramics up to 23% at T C . Above a critical Li doping amount, both negative and positive electrocaloric effect are observed in the same sample.

Optimization of Energy Storage Properties in Lead-Free Barium Titanate-Based CeramicsviaB-Site Defect Dipole Engineering

“…28 Eventually, the c/a value decreases slightly when x = 0.06, which may result from the segregation at the grain boundary caused by small excessive Li ions. 18 The maximum value of c/a is 1.0073 obtained at x = 0.04. It could be concluded that the addition of Li is favorable to optimize the crystallographic structure of BT ceramics.…”

“…15−17 For instance, Guvenc and Adem investigated the electrocaloric capacity in acceptor Li-doped BT ceramics. 18 Huang et al adopted Li + −Ho 3+ ionpair engineering to arouse the potential performance of electrostriction in BT ceramics and the large Q 33 of 0.06 m 4 C −2 obtained with low hysteresis in their work. 19 Lou et al analyzed the effect of the Li location in BT ceramics on the piezoelectric constant and dielectric property.…”

Advances in Electrospun Fiber‐Based Flexible Nanogenerators for Wearable Applications

“…Therefore, in most studies, lead-free BaTiO 3 , zinc oxide (ZnO), BZT-BCT, KNN, zinc sulfide (ZnS) was preferred instead of PZT. [112,[129][130][131][132]135] In earlier studies, different piezoelectric nanocrystals have been used together to enhance the electrical output of piezoelectric NGs. Sabry and Hussein added ZnO nanorods and BaTiO 3 nanospheres fillers to the PVDF fiber matrix, and a 12 V electrical output was observed under a force of 1.5 N. [131] Mostly, the piezoelectric nanofillers added also induce the PVDF 𝛽-phase that contributes to the improvement of the electrical performance of the material.…”

Enhanced electrocaloric response and energy storage performance of Li‐substituted BaTiO3 ceramics

“…Barium titanate has an ABO 3 type perovskite structure where the Ba +2 ions occupy at the A‐sites and the Ti +4 at B‐sites. In order to improve the EC response of BT ceramics, many isovalent dopants/co‐dopants at A‐ or B‐site were recently investigated 21–23 . Herein, we report the synthesis of Ba 1− x Li x TiO 3 ( x = 0, 0.01, 0.02, 0.03, 0.04, and 0.05) ceramics by the conventional solid‐state reaction method and the effect of Li doping on dielectric, leakage current, ferroelectric, electrocaloric, and energy storage properties of BaTiO 3 ceramics were systematically investigated.…”