Self-oscillating polymeric refrigerator with high energy efficiency

• 成果类型: Article
• 署名作者: Han, Donglin; Zhang, Yingjing; Huang, Cenling; Zheng, Shanyu; Wu, Dongyuan; Li, Qiang; Du, Feihong; Duan, Hongxiao; Chen, Weilin; Shi, Junye; Chen, Jiangping; Liu, Gang; Chen, Xin; Qian, Xiaoshi
• 署名单位: Shanghai Jiao Tong University; Shanghai Jiao Tong University; Shanghai Jiao Tong University; Shanghai Jiao Tong University
• 刊物名称: Nature
• ISSN/ISSBN: 0028-6493
• DOI: 10.1038/s41586-024-07375-3
• 发表日期: 2024-05-30
• 关键词: performance

摘要

Electrocaloric1,2 and electrostrictive3,4 effects concurrently exist in dielectric materials. Combining these two effects could achieve the lightweight, compact localized thermal management that is promised by electrocaloric refrigeration5. Despite a handful of numerical models and schematic presentations6,7, current electrocaloric refrigerators still rely on external accessories to drive the working bodies8-10 and hence result in a low device-level cooling power density and coefficient of performance (COP). Here we report an electrocaloric thin-film device that uses the electro-thermomechanical synergy provided by polymeric ferroelectrics. Under one-time a.c. electric stimulation, the device is thermally and mechanically cycled by the working body itself, resulting in an external-driver-free, self-cycling, soft refrigerator. The prototype offers a directly measured cooling power density of 6.5 W g-1 and a peak COP exceeding 58 under a zero temperature span. Being merely a 30-mu m-thick polymer film, the device achieved a COP close to 24 under a 4 K temperature span in an open ambient environment (32% thermodynamic efficiency). Compared with passive cooling, the thin-film refrigerator could immediately induce an additional 17.5 K temperature drop against an electronic chip. The soft, polymeric refrigerator can sense, actuate and pump heat to provide automatic localized thermal management. We report on a near-zero-power flexible heat pump that uses both electrocaloric and electrostrictive properties of a tailored polymer to create a chip-scale refrigerator device.