Breakdown Resistant Dielectrics and Self‐Extinguishing Engineering for Air Breakdown

The increasing energy demands of Internet of Things devices necessitate high-performance triboelectric nanogenerators (TENGs). However, the performance of TENGs is severely constrained by air and dielectric breakdown, which not only limits the energy output but also accelerates dielectric degradation and device failure. Here, a strategy is proposed to synergistically enhance the breakdown resistance and facilitate self-extinguishing of air breakdown by introducing an aluminum nitride (AlN) coating on dielectrics. The coating improves thermal dissipation capability and modulates the electric field and energy level distribution, enhancing dielectric breakdown resistance. Additionally, a spontaneously induced reversed electric field effectively suppresses air breakdown, preventing excessive discharge damage. Consequently, the modified polyimide (PI) and polytetrafluoroethylene (PTFE) exhibit significant improvements in both air and dielectric breakdown resistance. Corresponding TENGs achieve ≈ 50% increase in energy density and prominently extend operational stability by over 360 folds. This work provides insights into the thermal and interfacial processes of air breakdown, promoting the development of high-performance and durable TENGs.