Full-Electrochemical Construction of High-Performance Polypyrrole/Tellurium Thermoelectrical Nanocomposites

Abstract

As one of the most attractive inorganics to improve the thermoelectric (TE) performance of the conducting polymers, tellurium (Te) has received intense concern due to its superior Seebeck coefficient (S). However, far less attention has been paid to polypyrrole (PPy)/Te TE composites to date. In this work, we present an innovative full-electrochemical method to architect PPy/Te TE composite films by sequentially depositing Te with large S and PPy with high electrical conductivity (σ). Consequently, the PPy/Te composite films achieved excellent TE performance, with the largest power factor (PF) reaching up to 234.3 ± 4.1 μW m −1 K −2 . To the best of our knowledge, this value approaches the reported highest PF record (240.3 ± 5.0 μW m −1 K −2 ) for PPy-based composites. This suggests that the modified full-electrochemical method is a feasible and effective strategy for achieving high-performance TE composite films, which would probably provide a general guideline for the design and preparation of excellent TE materials in the future.

Tellurium/polymers for flexible thermoelectrics: status and challenges

“…Like the Te/PEDOT:PSS NC system as mentioned previously, the higher energy carriers hop across the interfacial potential barrier and the relatively low energy carriers are selectively scattered by the interfacial barrier, which result in an enhanced S and a higher thermoelectric PF. Li et al 208 developed a full-electrochemical method to prepare Te/PPy NC multilayer films. As illustrated in Fig.…”

Pulse Electrochemically Driven Multilayer Assembly of Single‐Walled Carbon Nanotube/Polypyrrole/Tellurium Composite Films for Ultra‐High‐Performance Flexible Thermoelectric Applications

“…[ 18 ] reported the first Te‐incorporated PPy composite utilizing the oxidative polymerization of pyrrole (Py) in the presence of a small amount of Te powder, and the PF reached as much as 23.89 µW m −1 K −2 at 373 K, which, in spite of a fairly moderate value, is about 859 times higher than that of the pure PPy. Very recently, our group further optimized the TE performance of the PPy‐based composites through an innovative electrochemical method, achieving the best PFs of 234.3 ± 4.1 µW m −1 K −2 for the PPy/Te composites [ 19 ] and 365.2 ± 9.6 µW m −1 K −2 for the PPy/SWCNT composites, [ 20 ] which are much higher than those of the corresponding composites reported previously.…”

“…Organic/inorganic nanocomposites with unique nanostructure are emerging as a preferential choice for flexible TE applications since they not only inherit the advantageous features from each component, that is, the high electrical conductivity (σ) and the large Seebeck coefficient (S) of inorganic ingredients, as well as the low thermal conductivity (κ) of organic counterparts, but also are endowed with novel interfacial chemistry, which of a fairly moderate value, is about 859 times higher than that of the pure PPy. Very recently, our group further optimized the TE performance of the PPy-based composites through an innovative electrochemical method, achieving the best PFs of 234.3 ± 4.1 µW m −1 K −2 for the PPy/Te composites [19] and 365.2 ± 9.6 µW m −1 K −2 for the PPy/SWCNT composites, [20] which are much higher than those of the corresponding composites reported previously.…”

“…[13] Nonetheless, with the development of organic/inorganic TE nanocomposites, the PPy has reawakened great interest of research in the TE application in the light of its low cost, high environmental stability, and good biocompatibility. [14][15][16] Currently, some milestone progresses for the PPy-based TE binary nanocomposites have been made, [17][18][19][20] profiting from the incorporation of the inorganic nanoparticles with high σ and/or large S, such as single-walled carbon nanotubes (SWCNTs) [21] and tellurium (Te), [22] the former of which possess ultra-high σ as well as good flexibility and large specific surface areas while the latter is a low-bandgap inorganic semiconductor with high S value of ≈400 µV K −1 at room temperature. For instance, by physically mixing the electrodeposited PPy with highly conductive SWCNTs, Fan et al [17] obtained a significantly improved PF of as high as 240.3 ± 5.0 µW m −1 K −2 for the PPy/SWCNT composites in 2019, which is the highest value for the PPy-based binary composites at that time.…”

Recent advances in interface engineering of thermoelectric nanomaterials

“…Summary of research on some interfacial engineering strategies for organic-inorganic composites[119][120][121][122][123][124][125][126][127][128][129][130][131][132] Composite s (S cm À1 ) S (mV K À1 ) PF (mW m À1 K À2 ) AE 4.1 187.5 AE 7.4 234.3 AE 4.1 PPy/SWCNTs 341.6 AE 4.7 33.2 AE 0.7 37.6 AE 2.3 AE 1.3 23.23 AE 4.76…”