Sustainable highly charged C-60-functionalized polyimide in a non-contact mode triboelectric nanogenerator

Abstract

In this paper, we report on a new dielectric, a C-60-containing block polyimide (PI-b-C-60). This was realized by introducing C-60 as pendent groups into a polymer backbone. When this dielectric was used in a non-contact mode triboelectric nanogenerator (TENG), it achieved high output power and reliable operation. Compared with perfluoroalkoxy alkane film-based TENGs, the TENG based on PI-b-C-60 generated 4.3 times higher output power and a superior charge density of over 300 mu C m(-2) with a 3 times slower charge decay rate. These results are most likely due to the excellent charge-retention characteristics induced by the most negative electrostatic potential of C-60 within the backbone, and these characteristics were confirmed by surface potential measurements. Furthermore, in the course of our work, two non-contact mode applications, a keyless electronic door lock system and a speed sensor with a tone wheel for a car, were developed. Without an ion injection process being needed, very sensitive and reliable operations of the speed sensor were successfully demonstrated, even under very humid conditions (similar to 99% RH).