Structural energy storage composites based on modified carbon fiber electrode with metal-organic frame enhancing layered double hydroxide

Structural energy storage composites present advantages in simultaneously achieving structural strength and electrochemical properties. Adoption of carbon fiber electrodes and resin structural electrolytes in energy storage composite poses challenges in maintaining good mechanical and electrochemical properties at reasonable cost and effort. Here, we report a simple method to fabricate structural supercapacitor using carbon fiber electrodes (modified by Ni-layered double hydroxide (Ni-LDH) and in-situ growth of Co-metal-organic framework (Co-MOF) in a two-step process denoted as Co-MOF/Ni-LDH@CF) and bicontinuousphase epoxy resin-based structural electrolyte. Co-MOF/Ni-LDH@CF as electrode material exhibits improved specific capacity (42.45 F center dot g-1) and cycle performance (93.3% capacity retention after 1000 cycles) in a three-electrode system. The bicontinuousphase epoxy resin-based structural electrolyte exhibits an ionic conductivity of 3.27 x 10-4 S center dot cm-1. The fabricated Co-MOF/Ni-LDH@CF/SPE-50 structural supercapacitor has an energy density of 3.21 Wh center dot kg-1 at a power density of 42.25 W center dot kg-1, whilst maintaining tensile strength and modulus of 334.6 MPa and 25.2 GPa. These results show practical potential of employing modified commercial carbon fiber electrodes and epoxy resin-based structural electrolytes in structural energy storage applications.

Automated summary

Structural energy storage composites offer the advantage of combining structural strength and electrochemical properties. This research presents a simple method for fabricating a structural supercapacitor using modified carbon fiber electrodes and epoxy resin-based structural electrolytes, demonstrating their practical potential in energy storage applications.