Interconnected Ni(OH)₂ and polyether amine on carbon fiber surface for simultaneously improving interfacial adhesion of epoxy composites and electrochemical properties

Interconnected Ni(OH)₂ nanoflakes and polyether amine (PEA) were deposited on carbon fiber tows via a facial and effective process of chemical bath deposition and dip coating. Based on this, a win–win benefit of simultaneously improvements in interfacial shear strength (IFSS) of carbon fiber/epoxy composites and the electrochemical activity has been achieved. Compared with CF and CF-Ni(OH)₂ composites, the IFSS of CF-Ni(OH)₂-PEA/epoxy composite respectively increased 7.9% and 45.4%, which was put down to the covalent bonding of Ni(OH)₂-PEA coating with fiber and epoxy matrix, as well as the effective stress transfer by the uniform honeycomb structure of Ni(OH)₂. In aqueous KOH electrolyte, the CF-Ni(OH)₂-PEA electrode presented the maximum specific capacitance of 689.98F·g⁻¹ at 5 mV·s⁻¹, 572.28F·g⁻¹ at a current density of 0.5 A·g⁻¹ due to the strong adhesion of carbon fiber with Ni(OH)₂ by PEA, the reservation of the three-dimensional hollow honeycomb structure of Ni(OH)₂ for easy ion-transport and –NH₂ functional groups from PEA for providing more active sites. The excellent performance of CF-Ni(OH)₂-PEA reinforcement demonstrates its promising potential for application in high performance composites with integrated structure and function, which shows great advantages in various fields of aerospace, energy, electronics, automobile, civil engineering, sports, etc.