A load-bearing/energy-storage integrated composite structural supercapacitor based on carbon nanotubes modified carbon fibers

Abstract

The electrification of transportation, such as aviation and electric vehicle, demands advanced energy storage systems that are lightweight with high energy and power densities. Composite structural supercapacitors (CSSs) that integrate load-bearing and energy storage functions present a promising solution. This study presents the fabrication and comprehensive evaluation of a CSS based on carbon nanotube-modified carbon fibers flexible supercapacitors combined with carbon fiber reinforced polymer, termed CNT-CSS. The CNT-CSS exhibits impressive electrochemical performance, featuring a specific capacitance of 333 mF g⁻1, an energy density of 416 mWh·kg⁻1, and a power density of 2850 mW kg⁻1. Mechanical tests reveal a flexural strength of 512 MPa and a flexural modulus of 15.5 GPa, indicating robust structural integrity. Furthermore, CNT-CSS maintains stable electrochemical performance under dynamic bending loads, impact conditions, and elevated temperatures. This study highlights the potential of CNT-CSS in functional carbon fiber composites, setting the stage for future applications in aviation and automotive industries.