Programmable nanolaminate architectures enable superior corona resistance through synergistic erosion blocking and...

The rapid expansion of electrification technologies, including electric vehicles (EVs), more-electric aircraft (MEA), and high-voltage power systems, demands polymer dielectrics with enhanced resistance to corona-induced degradation. However, scalable strategies for mitigating corona aging remain limited. Here, we report a self-assembled montmorillonite/poly(vinyl alcohol) (MMT/PVA) nanocoating with a programmable nanolaminate architecture as a facile surface-engineering approach for corona-resistant polymer dielectrics. By regulating crosslinking-mediated organic-inorganic interactions, the interlayer spacing is reduced to ∼2.5 nm, producing a compact nano-laminate structure with increased inorganic-layer redundancy and improved thermal and chemical stability. Systematic investigations reveal that decreasing interlayer spacing simultaneously strengthens two synergistic protection mechanisms: enhanced barrier resistance against discharge-induced through-thickness erosion and improved lateral charge dissipation enabled by the highly aligned MMT nanosheet network. As a result, electric-field distortion is mitigated, the partial-discharge inception field increases, and high-energy discharge events are effectively suppressed. Under elevated electric fields, the average magnitude of high-energy discharges decreases to ∼60% of that in pristine films, resulting in a transition from localized crater-like erosion to more dispersed surface damage. Consequently, under corona aging at 100 MV m^-1 and 50% relative humidity, the optimized nanocoating extends the characteristic lifetime of polyimide films to approximately 340% of that of the pristine polymer. These findings establish interlayer-spacing engineering as an effective strategy for simultaneously enhancing erosion resistance and charge dissipation, providing a scalable route to corona-resistant polymer dielectrics for harsh electrical environments.