Ion barrier layer-induced enhancement of ionic charge retention in triboelectric nanogenerators at high temperatures

Abstract

With the rapid development of the Internet of Things (IoT), sensors for extreme environments, such as fires or outer space, require triboelectric nanogenerators (TENGs) that perform reliably at high temperatures to provide sustainable energy. However, traditional TENGs face severe performance degradation due to thermionic emission at elevated temperatures. To address this, we introduced ion barrier layers (SiO₂ and polytetrafluoroethylene (PTFE)) to suppress thermionic emission and improve charge retention of injected ions. High-temperature experiments showed that the SiO₂ ion barrier significantly enhances charge retention, with further improvement observed using PTFE. Molecular dynamics (MD) and density functional theory (DFT) calculations were employed to elucidate the underlying mechanisms. MD simulations quantify the mean square displacements of injected ions, showing strong consistency with experimental results. DFT calculations evaluate the electrostatic potentials of various structures, revealing that interfaces with higher average electrostatic potential offer better charge retention. These findings provide a strategy for enhancing TENG performance in high-temperature environments and offer guidance for the design of TENG materials and structures for extreme applications.