Achievement of high n-type thermoelectric performance and stretchability in single-walled carbon nanotubes/polyethyleneimine /polyvinylpyrrolidone composites: Enabling self-healing and sensitive self-powered temperature sensors

In recent years, significant advancements have been made in enhancing the n-type thermoelectric (TE) performance of materials comprising organic molecules (OM)/single-walled carbon nanotubes (SWCNTs). Nonetheless, a key challenge is to develop n-type OM/SWCNT composites that can simultaneously demonstrate good stretchability, self-healing properties, and TE performance. In this study, we successfully developed self-healing n-type OM/SWCNT composites with remarkable mechanical and thermoelectric properties by incorporating the n-type dopant polyethyleneimine (PEI) and the biocompatible polymer polyvinylpyrrolidone (PVP). When the mass ratio of PEI to PVP is 3:7, the composite film displays a maximum strain of 32.58 %, meeting the requirements for applications in the wearable technology sector. Furthermore, it exhibits a power factor of 21.2 ± 0.5 μW m−1 K−2, which is among the highest for self-healing TE materials based on OM/SWCNTs. Following external damage and subsequent self-healing, the composite film showcases an impressive recovery of 89.4 % for power factor, which is the highest for self-healing TE materials. Additionally, self-powered temperature sensors demonstrate an impressive recovery of approximately 90.24 % of the output voltage when subjected to a temperature difference of 11 K. The composites possess remarkable self-healing properties, which make them suitable for recycling in wearable thermoelectric materials. [Display omitted] •SWCNT/PEI/PVP composites display high self-healing and n-type TE performance.•The composites maintain 89.4 % of the power factor after cutting and self-healing.•Self-powered temperature sensors with self-healing capabilities are fabricated.