Self-boosted power generation of triboelectric nanogenerator with glass transition by friction heat

Inevitable frictional heat, generated by friction, degrades output performance of polymer-based triboelectric nanogenerators (TENGs). To address this issue, we propose to take advantage of using shape memory effect of polyurethane (PU) as a triboelectric layer to not only operate TENG sustainably, but also realize self-boosting power generation performance of TENG by frictional heat. We found that frictional heat sufficiently leads to the glass transition of PU and this transformed PU at elevated temperature contributes to change key parameters, serving to improve performance of TENG, including dielectric constant, work function, and charge trap density. In this work we verified PU harness heat generated by friction and demonstrated 300% increase of the power-generating performance of PU-based TENG with experiencing the glass transition. In addition, we experimentally observed no further temperature elevation around 60 °C in TENG with a continuous rotating friction mode, which offers PU potential to be a promising triboelectric material for high performance TENGs. We demonstrate the self-boosted output performance of triboelectric nanogenerator (TENG) with polyurethane (PU) as a triboelectric polymer. Output perfomance of PU-based TENG can be significantly enhanced by the friction-heat-induced property change of PU such as dielectric constant, work function, and trap site density. In addition, we experimentally observed the output performance PU-based TENG is stable due to self-limited temperature increase up to 60 °C by glass transition in the continuous friction process. [Display omitted] •We introduce an intriguing approach to overcome a power degradation of triboelectric nanogenerators (TENGs) induced by a temperature rise due to friction heat.•Our findings show that polyurethane (PU) undergoes a glass transition at 55 °C, which gives rise to improve thereof dielectric constant, work function, and trap site density.•We confirmed that the output performance of PU-based TENG was improved by 300% during operating TENG without any help of additional device and temperature of PU-based TENG is self-stabilized around 60 °C after temperature increase up to around 80 °C in the free-standing rotation mode with the continuous friction.