Charge capturing effects of boron nitride nanosheets on enhanced triboelectric properties of polyimide nanocomposite films in a conductor-to-dielectric mode

Dielectric composite materials play a crucial role in the performance of triboelectric nanogenerators (TENGs) by influencing charge storage and transfer capabilities. In this study, we investigate the influence of boron nitride nanosheets (BNNS) on the triboelectric properties of polyimide (PI)-based dielectric nanocomposite films within a TENG setup employing a conductor-to-dielectric configuration and a contact-separation mode. To achieve this, we manufactured PI/BNNS nanocomposite films containing 1–10 wt% BNNS with a thickness of ∼14.67 nm via a solution casting method, followed by thermal imidization. Thermogravimetric characterization revealed that the thermal stability of the nanocomposites improved with increasing BNNS content. Additionally, the triboelectric performance of the PI/BNNS films, used as the negative friction layer, was enhanced due to the electron-trapping capabilities at the BNNS-PI interface. Among the samples, the nanocomposite film containing 5 wt% BNNS exhibited the most significant triboelectric output, generating a voltage of ∼4.0 V and a current of ∼426.4 nA. Moreover, the triboelectric AC output generated by the TENG using PI/BNNS nanocomposite films was successfully rectified into DC signals and subsequently stored in microcapacitors. This capability highlights the significant potential of PI/BNNS nanocomposite films for energy harvesting and storage applications, further supporting their suitability for integration into advanced flexible energy devices.