Environmentally friendly super-insulating material with three-dimensional nanoporous structure: A promising candidate for future gas insulated transmission lines and carbon sequestration

Abstract

Gas-insulated transmission lines (GILs) play a pivotal role in facilitating the future long-distance transmission of power generated by renewable energy. However, the extensive employment of gaseous SF6 presents formidable obstacles to scaled application of GILs, due to its relatively low breakdown strength and substantial greenhouse effect. In this work, a fantastic phenomenon was discovered that the breakdown field strength of insulating gases can be significantly enhanced under the confinement of nanostructures, based on it, the starch/polyorganosiloxane biocomposite insulating dielectric (S/PBID) with three-dimensional nanoporous structure was designed and fabricated. Specifically, insulating gases (CO2, N2, SF6) composite with S/PBID, the breakdown field strength is significantly improved by 744.44 %, 520.74 %, and 310.95 % compared to the original gases, respectively. The relative permittivity of S/PBID (<2) is considerably lower than that of most existing insulating materials. Theoretical analysis suggests that the nanopores within S/PBID restricts electron multiplication and transport processes at the lateral scale, leading to a substantial enhancement in gas breakdown field strength. The nanoporous material is expected to be composited with atmospheric CO2 to overturn the conventional gas–solid composite insulation form of the GILs, thereby providing a novel insulation form of high-performance, environmental-friendly, and carbon sequestration.