Conductivity and Conductive Stability of Nickel-Plated Carbon-Fiber-Reinforced Cement Composites

The conductivity and wettability of carbon fiber increase with nickel-plating coating thickness, which may improve the conductivity and stability of carbon-fiber-reinforced cement composites (CFRCs). To investigate the influence of carbon-fiber metal coating on the CFRC conductivity and stability, nickel-plated carbon fibers (NPCFs) were prepared by electroless plating, and the influence of NPCF content, contact resistance, coating thickness, age, temperature and water content on the conductivity and conductive stability of NPCF-reinforced cement composites (NPCFRCs) was investigated. The NPCF wettability and roughness were enhanced significantly with the increase in coating thickness, and the NPCF dispersion was also enhanced, which improves the NPCFRC conductivity and stability. The NPCF percolation threshold decreased by 50% and the NPCF contact resistance decreased from 422 Ω to 76 Ω when the coating thickness increased from 0 to 2.25 microns. The difference between the 180- and 28-day resistivities decreased from 1170.9 to 141.0 Ω cm, which indicates that the conductivity and conductive stability of the NPCFRC were enhanced significantly. The conductivity and stability of the CFRC that were prepared with NPCF improved notably, which promotes the application of CFRC in structural health monitoring and thermoelectric conversion.