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

Abstract Although several efforts were made to develop high‐performance thermoelectric (TE) composites by a combination of single‐walled carbon nanotubes (SWCNTs) with a high conductivity and tellurium (Te) with a large Seebeck coefficient, only a very limited advance has been achieved because of their intrinsic interfacial incompatibility. In this work, a range of SWCNT/polypyrrole (PPy)/Te flexible composite films are prepared through sequentially pulse electrodepositing PPy and Te over the prefabricated SWCNT membrane electrode, where both the introduction of the PPy sandwich layer and the adoption of two pulse electrodepositions play a vital role in ameliorating the TE performance of the composites via the synergic optimization of an interfacial engineering. Consequently, the best power factor for the optimal SWCNT/PPy/Te composite film reaches up to 1602.4 ± 87.6 µW m −1 K −2 at 300 K, which hits the record for the p‐type PPy‐based TE composites. Moreover, the five‐leg flexible thermoelectric generators assembled with the optimal film harvest an output power of 1512.5 nW at the applied temperature difference of 22.4 K. This work suggests that the multilayer assembly technology driven by pulse electrochemistry is a feasible and effective tactic for architecting high‐performance flexible TE films.