A Bi2Te3-Filled Nickel Foam Film with Exceptional Flexibility and Thermoelectric Performance

Abstract

The past decades have witnessed surging demand for wearable electronics, for which thermoelectrics (TEs) are considered a promising self-charging technology, as they are capable of converting skin heat into electricity directly. Bi2Te3 is the most-used TE material at room temperature, due to a high zT of ~1. However, it is different to integrate Bi2Te3 for wearable TEs owing to its intrinsic rigidity. Bi2Te3 could be flexible when made thin enough, but this implies a small electrical and thermal load, thus severely restricting the power output. Herein, we developed a Bi2Te3/nickel foam (NiFoam) composite film through solvothermal deposition of Bi2Te3 nanoplates into porous NiFoam. Due to the mesh structure and ductility of Ni Foam, the film, with a thickness of 160 μm, exhibited a high figure of merit for flexibility, 0.016, connoting higher output. Moreover, the film also revealed a high tensile strength of 12.7 ± 0.04 MPa and a maximum elongation rate of 28.8%. In addition, due to the film’s high electrical conductivity and enhanced Seebeck coefficient, an outstanding power factor of 850 μW m−1 K−2 was achieved, which is among the highest ever reported. A module fabricated with five such n-type legs integrated electrically in series and thermally in parallel showed an output power of 22.8 nW at a temperature gap of 30 K. This work offered a cost-effective avenue for making highly flexible TE films for power supply of wearable electronics by intercalating TE nanoplates into porous and meshed-structure materials.

MXene Nanosheet/Organics Superlattice for Flexible Thermoelectrics

“…8 Therefore, depositing a thin layer of inorganic materials onto flexible substrates or into porous structures can achieve a certain degree of flexibility as well as a good TE performance. Recently, Shi et al 9 synthesized a Bi 2 Te 3 /nickel foam composite film by depositing nanosized Bi 2 Te 3 into the nickel foam by a hydrothermal method, which revealed good flexibility and an increased PF. Loureiro et al 10 deposited the low-cost, earth-abundant, and environmentally friendly material aluminum zinc oxide (AZO) by radio frequency and pulsed direct-current magnetron sputtering.…”

Advances in flexible inorganic thermoelectrics

“…6 Therefore, the rational selection of composite materials is also one of the recent key research focuses. [79][80][81] To illustrate the design of different substrates for fabricating flexible bismuth/antimony chalcogenides, [82][83][84] van der Waals epitaxy (vdWE) Bi 0.5 Sb 1.5 Te 3 (BST) thin film was fabricated on a sapphire substrate by an ultraviolet (UV)-pulsed laser deposition (PLD) method, as shown in Figure 3A. 85 The film was subsequently peeled off by etching in a dilute HF solution and transferred onto a flexible substrate to form a high-performance flexible thermoelectric film.…”

Electronic Structure and Transport Properties of Bi2Te3 and Bi2Se3 Single Crystals

“…This, in turn, can be used in various devices. Due to their special surface states, Bi 2 Te 3 and Bi 2 Se 3 have great application potential and are successfully used in spintronic [15][16][17][18] and thermoelectronic [19][20][21][22][23] devices, biological and chemical sensors [24][25][26], and photonic and optoelectric applications [27,28]. Therefore, obtaining new information about the features of the electronic structure and electronic transport in such topological materials is of great interest and is relevant from both fundamental and applied points of view.…”