Electrostatic breakdown at liquid-solid-gas triple-phase interfaces owing to contact electrification

Electrification at water-solid interfaces, which enhances interfacial physical and chemical reactions, plays a crucial role in energy fields. However, the fundamental limits on charge transfer due to contact electrification (CE) at these interfaces remain poorly understood. Here, we first demonstrate electrostatic breakdown (EB) in the vicinity of liquid-solid-gas interfaces, which is attributed to the enhanced electric field in the gas close to the triple-phase contact line. Furthermore, we discover the significant impact of distant conductors on the interface electric field depending on their locations and grounding statuses and observe two types of breakdowns. Guided by an established physical model of breakdown, we achieve a record-high charge density of 1.36 mC m⁻² in CE at water-insulator interfaces. Finally, we show the broad impact of EB on energy harvesting, surface wettability, and droplet motion at water-insulator interfaces. This previously unexplored EB phenomenon could offer new insights into interfacial charge and energy exchange at water-solid interfaces.