Electrocaloric effect (ECE) is much promising to realize high efficiency and environment friendly solution in solid cooling devices. Relaxor ferroelectrics are good candidates for the materials with high electrocaloric cooling power. In this paper, relaxor ferroelectric Ba(Zr_xTi_1–x)O₃ (BZT, x = 0.2, 0.21, 0.22, 0.23) ceramics were prepared with their temperature change (ΔT) induced by the ECE and electrocaloric strength (ΔT/E) measured within broad temperature range. It is found that the BZT21 (x = 0.21) exhibits the largest ΔT of ∼4.67 K and a high ΔT/E value of ∼0.46 km/MV at 9.9 MV/m and 25 °C. BZT21 also exhibits apparent relaxor ferroelectric response, showing a very broad EC peak in the temperature interval between 15 °C and 50 °C. Moreover, the relationship between EC properties and relaxor features was analyzed by piezoresponse force microscopy test. The results reveal that more dispersed phase structures induce additional configurational entropy, which is in favor for the enhanced EC performance. The interplay and compromise between the kinetic and thermodynamic mechanisms of domain switching determines the optimal composition for the EC performances of the BZT ceramics.

电热效应（ECE）有望在固体冷却装置中实现高效和环境友好的解决方案。弛豫铁电体是具有高电热冷却能力的材料的良好候选者。本文制备了弛豫铁电 Ba(Zr _x Ti _{1– x} )O ₃ (BZT, x  = 0.2, 0.21, 0.22, 0.23) 陶瓷，其温度变化 (Δ T ) 由 ECE 和电热强度 (Δ T / E ) 在广泛的温度范围内测量。发现 BZT21 ( x  = 0.21) 表现出最大的 Δ T ~ 4.67 K 和高 Δ T / E在 9.9 MV/m 和 25 °C 时的值为 ∼0.46 km/MV。BZT21 还表现出明显的弛豫铁电响应，在 15 °C 和 50 °C 之间的温度区间内显示出非常宽的 EC 峰。此外，通过压电响应力显微镜测试分析了 EC 特性与弛豫特征之间的关系。结果表明，更分散的相结构会产生额外的构型熵，这有利于增强 EC 性能。域转换的动力学和热力学机制之间的相互作用和折衷决定了 BZT 陶瓷 EC 性能的最佳组成。