Energy storaging multifunctional carbon fiber composites based on Nano‐<scp>SiO₂</scp> reinforced epoxy matrix structural electrolytes

Abstract Multifunctional carbon fiber composite materials capable of storing energy and carrying structural loads have advantages for aerospace structures. In this paper, a structural supercapacitor that consists of an epoxy‐based solid polymer electrolytes (E‐SPEs) and carbon fiber was proposed. To develop an E‐SPEs with better mechanical properties and ionic conductivity, Nano‐SiO 2 was introduced into the solid polymer electrolytes. Nano‐SiO 2 reinforced E‐SPEs (Nano‐SiO 2 /E‐SPEs) show improved mechanical properties (Young's modulus [ E ] = 0.85 GPa) and ionic conductivity (4.99 × 10 −4 S cm −1 ), compared to E‐SPEs without Nano‐SiO 2 . Structural supercapacitors were further prepared by combining E‐SPEs with carbon fibers. The structural supercapacitor prepared with Nano‐SiO 2 /E‐SPEs exhibits the higher power and energy density (261.93 W kg −1 and 2.11 Wh kg −1 ) compared to the structural supercapacitor prepared with E‐SPEs without Nano‐SiO 2 (51 W kg −1 and 0.34 Wh kg −1 ), indicating improved mechanical and energy storage properties for structural supercapacitors after incorporation of Nano‐SiO 2 . This strategy has great potential in enhancing performance of structural energy storage composite materials for application in next‐generation aerospace vehicles.