Mechanical and electrochemical performance of hybrid laminated structural composites with carbon fiber/ solid electrolyte supercapacitor interleaves

The concept of “structural power composites” has motivated considerable research interests in the past decade. The purpose of this research is to demonstrate the feasibility of fabricating a hybrid composite laminate composed of structural and functional components; the former is consisted of four layers Kevlar fabric/epoxy prepregs and the latter is a thin interleaf of carbon fiber/solid electrolyte supercapacitor. The excellent electrochemical and mechanical performance has been demonstrated for the model laminate with electrode-normalized value of specific capacitance, energy density and power density of 3.79 F cm⁻³, 3.37 × 10⁻⁴ Wh cm⁻³ and 0.04 W cm⁻³, respectively, as well as laminate flexural strength and flexural modulus of 192 MPa and 9.3 GPa, respectively. The mechanical behavior of the hybrid composite was characterized by static and cyclic flexural loading as well as X-ray micro-computed tomography (μ−CΤ) imaging. The electrochemical stability of the supercapacitor was validated by the high capacitance retention under galvanostatic charge-discharge cycling as well as cyclic flexural loading. Lastly, the potential of scaling up the number of imbedded supercapacitor for adjustable energy storage capacity has been demonstrated.