A self-healable, recyclable, and flexible thermoelectric device for wearable energy harvesting and personal thermal management. (1st June 2023)

• Record Type: Journal Article
• Authors: Zhu, Pengcheng; Luo, Xuepeng; Lin, Xinran; Qiu, Zhichong; Chen, Rongrui; Wang, Xiangcheng; Wang, Yaling; Deng, Yuan; Mao, Yanchao
• Is Part Of: Energy conversion and management. Volume 285(2023)
• Publication Date: 2023-06-01
• Subjects: Flexible thermoelectric device -- Self-healable -- Recyclable -- Large power -- Personal thermal management; Direct energy conversion -- Periodicals; Energy storage -- Periodicals; Energy transfer -- Periodicals; Énergie -- Conversion directe -- Périodiques; Direct energy conversion; Periodicals; 621.3105
• DOI: 10.1016/j.enconman.2023.117017
• Languages: English
• ISSNs: 0196-8904

Abstract

Graphical abstract: We developed a self-healable and recyclable flexible thermoelectric device (f-TED) that simultaneously possesses large normalized power density and high cooling effect. This f-TED can directly light an LED bulb by harvesting body heat, and realize personal thermal management to keep skin at comfort zone. This device paves the way for next-generation f-TEDs used in wearable power source and personal thermal management. Highlights: A self-healable, recyclable, and flexible f-TED with optimal design is developed. A power density of 1.54 μW·cm −2 ·K −2 was realized for wearable power source. A record 13.8 °C on-body cooling was delivered for personal thermal management. A COP value of 3.91 at 7 °C of cooling effect was achieved. The f-TED shows only slight performance decay after self-healing and recycling. Abstract: Flexible thermoelectric devices (f-TEDs) can realize direct energy conversion between heat and electricity, which hold great prospects in wearable power source and personal thermal management. However, conventional f-TEDs made from intrinsically flexible thermoelectric materials have low power density, and elastomer sealed bulk thermoelectric materials-based f-TEDs can hardly achieve active cooling. Additionally, these f-TEDs usually are not self-healable and recyclable, which easily occur fractures in wearable applications. Here, we developed a self-healable and recyclable f-TED by integrating dynamic covalent thermoset polyimine with liquid metal and thermoelectric legs. This f-TED achieves a normalized power density of 1.54 μW·cm −2 ·K −2, and can deliver a record 13.8 °C on-body cooling effect with a high coefficient of performance (COP) at 3.91 under 7 °C temperature difference, which leads to a low power consumption of ∼ 38 W for the cooling of regular human body. Based on the f-TED, we further developed a personal thermal management system, which can keep body within comfort zone at different surrounding temperatures, also realize healthcare function for fever or sprained ankle. Compared with conventional thermoelectric devices, this f-TED can simultaneously achieve self-healability, recyclability, flexibility, large normalized power density, and high on-body cooling effect with low power consumption. Such f-TED could open up new opportunities to develop devices for wearable energy harvesting and personal thermal management.