Dynamically cross-linked polyethylene cable insulation with superior wide-temperature-range dielectric stability and reprocessability

High-voltage direct-current (HVDC) cables are essential for reliable and efficient transmission of large-scale renewable energy, while it has been an obstacle to develop high-performance insulating materials. Specifically, achieving simultaneous suppression of space charge and stabilization of conductivity across a wide temperature range has remained elusive. Here, we prepared dynamically cross-linked polyethylene (PE-SH_x) samples through a byproduct-free thiol-anhydride click-like reaction to address this contradiction. Reversible thioester bonds construct a recyclable and repairable network, while functioning as thermally robust polar traps. The optimized PE-SH₁₀₀ sample exhibited comprehensive improvements over the state-of-art commercial XLPE. Its conductivity was reduced by 47% at 30 °C and 93% at 90 °C with a sufficiently lowed activation energy of 0.27 eV. In addition, space charge accumulation was suppressed by 94% and electric field distortion remained below 5% even at 90 °C. This study established dynamic thioester bonds as an effective molecular strategy to reconcile trap regulation with conductivity stabilization, thereby endowing next-generation HVDC cable insulation with superior electrical insulation, wide-temperature-range stability, and reprocessability.