High-Performance Multifunctional Structural Supercapacitors Based on <i>In Situ</i> and <i>Ex Situ</i> Activated-Carbon-Coated Carbon Fiber Electrodes
Yinghui Ding, Guocheng Qi, Qian Cui, Jiping Yang, Boming Zhang, Shanyi Du
Abstract
With the rapid consumption of fossil fuels and the massive emission of pollutants, multifunctional materials are the upgrading trend of automotive and aerospace structures. As a promising structural energy storage device, the specific capacitance of a carbon-fiber-based structural supercapacitor is greatly limited as a result of the low specific surface area of carbon fiber electrodes. In this work, we prepared high-performance structural supercapacitors that consisted of in situ and ex situ activated carbon (AC)-coated carbon fiber electrodes, glass fiber separator, and bicontinuous structural electrolyte. The specific capacitances of the structural supercapacitors increased from 8.67 × 10–3 to 13.12 F/g after the coating of AC, while the tensile properties were basically maintained, which were much higher than the results of the state-of-art performance for structural supercapacitors. The tensile strength and modulus were 257.78 MPa and 23.20 GPa, respectively, as the mass fraction of AC increased to 15%. A total of 95% of the capacitance could be maintained in structural supercapacitor devices with a larger size of 15 × 15 cm, showing promising engineering prospects of AC-coated structural supercapacitors. The method in this work provided a facile route for realizing the large-scale production and engineering application of high-performance structural supercapacitors.