Abstract：
We created solution-processed electrocaloric (EC) materials based on the ferroelectric polymer nanocomposites consisting of BST nanoparticles and boron nitride nanosheets. The composites presented a pronounced room-temperature ECE, including a giant cooling energy density of 129.2 MJ m-3 and a high temperature change of 50.5 oC. Subsequently, by substituting PMN-PT for BST acted as the nanofillers, the operating temperature of the composites has been successfully extended. The composite with PMN-PT exhibits enhanced ECE in a wide temperature range from 0-60 oC. Furthermore, compared to the polymer composites composed of ferroelectric nanoparticles, nanocubes and nanorods, the composites consisting of nanowires have much higher breakdown and EC strengths which are attributable to the high aspect ratio of nanofillers. Consequently, greater ECE has been achieved in the nanowire composites. The excellent ECE features of the polymer nanocomposites, together with simplicity in preparation and scalability in size and shape, open up new perspectives for developing light, compact and environmentally friendly solid-state cooling devices.

摘要：
外加电场可使铁电材料的电畴翻转，甚至诱导相变。铁电材料的电卡效应正是利用其电畴翻转和相变所形成的熵变来实现吸热制冷。研究了PVDF基聚合物-氮化硼纳米片-钛酸锶钡（BST）三元纳米复合铁电材料在室温下的电卡效应，得到较好的综合性能：材料制冷密度为129.2 MJ m-3、温降达到50.5 oC；在此基础上，利用铌镁酸铅-锆钛酸铅（PMN-PT）取代BST作为填充物，拓宽了复合电卡材料的使用温区，使其在0-60 oC较宽的温度范围内展现了较高的电卡效应。此外，通过改变BST纳米填充物的形貌，进一步优化了复合材料的综合电卡效应。研究发现，采用纳米线作为填充物制备的复合材料具有较纳米颗粒、纳米立方体和纳米棒等复合材料更强的电卡效应。理想的电卡效应、良好的柔韧性和简单的制备工艺使纳米复合电卡材料具有广阔的应用前景，对下一代节能环保型制冷器的研制具有重要意义。

个人简介：
张光祖，华中科技大学光学与电子信息学院副教授、博士生导师，教育部敏感陶瓷工程技术中心副主任。2013.3-2016.10期间，在宾夕法尼亚州立大学材料科学与工程系从事博士后研究工作。致力于铁电、介电陶瓷及其聚合物纳米复合功能材料与器件的基础和应用研究，开发了高效制冷用电卡复合材料与器件、高性能陶瓷及纳米复合储能材料与电容器，以及非制冷红外焦平面阵列用热释电陶瓷材料。发表了Nature在内的SCI论文51篇，其中以第一和（或）通讯作者发表Advanced Materials、ACS Nano和Energy and Environmental Science等论文25篇。2篇论文成为ESI高被引论文，成果3次被选作当期杂志的封面或封底。任Advanced Materials、Journal of the American Ceramic Society和Journal of Materials Chemistry C等十余个SCI国际知名杂志的审稿人。获授权国家发明专利6项，获日内瓦国际发明展会银奖2项。