Advanced Thermoelectric Materials for Flexible Cooling Application

Abstract

Flexible cooling devices, which aim to fulfill the essential requirement of complex working environments and enable local heat dissipation, have become the cutting‐edge area of refrigeration technology. Thermoelectric (TE) material represents a promising candidate for various flexible cooling applications, including wearable personal thermoregulation devices. With the increasing interest in the Peltier effect of conductive polymers and inorganic films on flexible substrates, flexible cooling devices have undergone rapid development. Herein, the fundamental mechanisms, basic parameters, and temperature measurement techniques for evaluating the cooling performance are summarized. Moreover, recent progress on TE materials, such as flexible inorganic and organic materials for Peltier cooling studies, is reviewed. More importantly, insights are provided into the key strategies for high‐performance Peltier devices. The final part details the existing challenges and perspectives on flexible TE cooling to inspire additional research interests toward the advancement of refrigeration technology.

Thermoelectric Coolers: Progress, Challenges, and Opportunities

“…[ 80 ] Therefore, it is of significance to design high‐performance TE materials with high ZT s, especially at near‐room temperatures since most of TECs functionalize at near‐room temperatures. [ 19,51,65,77,81,82 ] Figure 2b compares reported peak ZT s of bulk TE materials reported in recent years, including Bi 2 Te 3 , [ 83 ] Bi 0.5 Sb 1.5 Te 3 (BST), [ 84 ] SnTe, [ 85 ] Mg 3 Sb 2 Zintl, [ 86 ] Cu 2 Se composites, [ 87 ] GeTe, [ 88 ] half‐Heusler, [ 89 ] PbTe, [ 90 ] skutterudite, [ 91 ] SnSe, [ 92 ] BiCuSeO, [ 93 ] and SrTiO 3 . [ 94 ] Other TE materials such as Mg 2 Si ( ZT = 1.4 at 800 K), [ 95 ] Cu 2 S 1‐ x Te x ( ZT = 2.1 at 1000 K), [ 96 ] AgSbTe 2 ( ZT = 2.1 at 573 K), [ 97 ] and clathrate ( ZT = 1.45 at 500 K), [ 98 ] and also shows their high TE potentials.…”

“…[ 63 ] As well, the recent applications of TEs on medication were reviewed, [ 131,132 ] as well as the progress on flexible TEs and their cooling applications. [ 78,81,133 ] However, considering the recent rapid development of TECs, it is of great significance to maintain its up‐to‐the‐date progress. In this work, we provide a targeted review of the progress, challenge, and outlooks of TECs based on their design, structures, fabrications, characteristics, performance, and broad application scenarios.…”

Advances in organic thermoelectric materials and devices for smart applications

“…Seebeck coefficient ( S ) is defined as S = Δ V/ Δ T , where Δ V and Δ T are output voltage and temperature difference, which provide a comprehensive insight into the energetics of the dominant charge transport process and is determined by the characteristics of the band structure and scattering events. In contrast, the Peltier effect occurs when the current flows through an isothermal junction between two materials 32–34 . Hence, another fundamental TE parameter (Peltier coefficient) is referred to describe current ( I ) induced energy diffusion via the expression d Q/ d t = (Π a ‐ Π b ) × I , where d Q/ d t is the rate of heat generation, Π a and Π b are the Peltier coefficients of the two materials.…”

Personal air-conditioning system using evapolar as heat waste management

“…It is proven to overcome waste energy consumption in portable air conditioning, Peltier module was used. Hot effects on the hot side of the Peltier module cannot fully be utilized while vice versa on the cold sides [14], [15]. The problem with the hot sides that not be used in Peltier module must be utilized because portable air conditioning using Peltier module have a great achievement in transferring cool air to surroundings [16], [17].…”