Ultrafast and Cost-Effective Fabrication of High-Performance Carbon-Based Flexible Thermoelectric Hybrid Films and Their Devices

Abstract

Due to their cost-effectiveness and industry-scale feasibility, carbon-based composites have been considered to be promising thermoelectric materials for low-grade power generation. However, current fabrications for carbon-based composites are time-consuming, and their thermoelectric properties are still low. Herein, we develop an ultrafast and cost-effective hot-pressing method to fabricate a novel carbon-based hybrid film, which consists of ionic liquid/phenolic resin/carbon fiber/expanded graphite. This method only costs no more than 15 min. We found that the expanded graphite as the major component enables high flexibility and the introduction of phenolic resin and carbon fiber enhances the shear resistance and toughness of the film, while the ion-induced carrier migration contributes to a high power factor of 38.7 μW m–1 K–2 at 500 K in the carbon-based hybrid film. After the comparison based on the ratios between the power factor with fabrication time and cost among the current conventional carbon-based thermoelectric composites, our hybrid films show the best cost-effective property. Besides, a flexible thermoelectric device, assembled by the as-designed hybrid films, shows a maximum output power density of 79.3 nW cm–2 at a temperature difference of 20 K. This work paves a new way to fabricate cost-effective and high-performance carbon-based thermoelectric hybrids with promising application potential.

All‐Automated Fabrication of Freestanding and Scalable Photo‐Thermoelectric Devices with High Performance

“…[ 15a,17,19 ] Automation generally represents an effective way to lower the cost of manufacturing, which often increases the productivity of PTE device fabrication, saves human power, improves safety, etc. The cost‐effectiveness of 4.02 µW g m −1 K −2 $ −1 was calculated (Table S5, Supporting Information) according to the literature, [ 29 ] which may be further improved to ≈61.1 µW g m −1 K −2 $ −1 by using cheap and high‐performance multiwalled CNTs, [ 15a ] showing the promising large‐scale application potential.…”

Weavable thermoelectrics: advances, controversies, and future developments

“…However, despite the clear advantages of carbon materials as the core of weavable thermoelectric materials and devices, their drawbacks are also quite evident. Compared to some other thermoelectric materials, carbon-based devices exhibit relatively lower thermoelectric efficiency [190,191]. While they possess high σ, their κ is also relatively high, which can result in reduced thermoelectric performance.…”

Advances in flexible inorganic thermoelectrics

“…Combining the material with highly flexible materials such as CNTs and graphene is one of the effective ways to further improve the overall thermoelectric performance and flexibility of bismuth/antimony chalcogenide thin films. 71,[88][89][90][91][92] This is because carbon-based materials usually have high σ and high flexibility, [93][94][95][96][97] but their κ is also high, 12,93 which should be carefully considered during the hybrid design such as optimizing the content and distribution of these carbon-based materials. Figure 3F shows a TEM image of a single-wall carbon nanotube (SWCNT) network with (000l) textured Bi 2 Te 3 nanocrystals on it.…”