School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, China.
Engineering Research Center for Functional Ceramics, Ministry of Education, Huazhong University of Science and Technology, Wuhan, 430074, China.
Adv Mater. 2019 Feb;31(8):e1806642. doi: 10.1002/adma.201806642. Epub 2019 Jan 7.
The electrocaloric effect (ECE) offers a unique mechanism to realize environmentally friendly and highly efficient solid-state cooling that completely differs from the conventional vapor-compression refrigeration. Here a new class of hybrid films composed of ferroelectric polymer nanowire array and anodic aluminum oxide (AAO) membrane is reported, which displays pronounced ECE driven by relatively low electric fields. Under confinement and orientation of AAO channels on the crystallization of the polymer, the polymer nanowire array shows substantially enhanced ECE that is about three times that of the corresponding thin films. Simultaneously, the integrated AAO membrane forms thermally conducting channels for the polymer nanowires, enabling the efficient transfer of cooling energy and operation of the EC materials under high frequencies, which are unattainable based on the currently available EC structures. Consequently, the integrated polymer nanowire-AAO hybrid film exhibits the state-of-the-art cooling power density, outperforming the current ferroelectric polymers, ceramics, and composites. This work opens a new route for the development of scalable, high-performance EC materials for next-generation refrigeration.
电卡效应（ECE）提供了一种独特的机制，可以实现环保且高效的固态冷却，这与传统的蒸汽压缩制冷完全不同。在这里，我们报道了一类由铁电聚合物纳米线阵列和阳极氧化铝（AAO）膜组成的新型混合薄膜，它在相对较低的电场下表现出明显的电卡效应。在聚合物结晶过程中 AAO 通道的限制和定向作用下，聚合物纳米线阵列表现出显著增强的电卡效应，大约是相应薄膜的三倍。同时，集成的 AAO 膜为聚合物纳米线形成了热传导通道，使冷却能量的高效传递成为可能，并且在高频下也能运行 EC 材料，这是目前可用的 EC 结构所无法实现的。因此，集成的聚合物纳米线-AAO 混合薄膜表现出了最先进的冷却功率密度，超过了目前的铁电聚合物、陶瓷和复合材料。这项工作为开发下一代制冷用可扩展、高性能的 EC 材料开辟了新途径。
