Impact of MXene on the positive temperature coefficient (PTC) properties of semiconductive composites and space charge accumulation in insulation

Abstract The accumulation of space charges in high-voltage cable insulation layers significantly compromises electrical performance and accelerates material degradation. This study proposed a novel strategy to inhibit charge injection by incorporating highly conductive annealed MXene nanosheets into the semiconductive shielding material. Results demonstrate the introduction of MXene remarkably reduce positive temperature coefficient (PTC) of composites. With MXene content of 0.5 wt% (carbon black (CB) of 31.5 wt%), the PTC of composite decreases to 3.6 from 5.74 (pure CB sample), indicating enhanced thermal stability. Furthermore, MXene modified materials effectively suppress space charges accumulation, reducing the charge density in the insulation layer to 13.38 C/m 3 (MXene content of 0.5 wt%) compared to 20.44 C/m 3 for unmodified sample. These enhancements are attributed to MXene’s dual role in forming efficient conductive networks and introducing deep charge traps. This study sheds new light on the development of advanced semiconductive shielding materials for high-voltage cable applications.