title: Multifunctional structural supercapacitor composites based on carbon aerogel modified high performance carbon fiber fabric.
abstract: A novel multifunctional material has been designed to provide excellent mechanical properties while possessing a high electrochemical surface area suitable for electrochemical energy storage: structural carbon fiber fabrics are embedded in a continuous network of carbon aerogel (CAG) to form a coherent but porous monolith. The CAG-modification process was found to be scalable and to be compatible with a range of carbon fiber fabrics with different surface properties. The incorporation of CAG significantly increased the surface area of carbon fiber fabrics, and hence the electrochemical performance, by around 100-fold, resulting in a CAG-normalized specific electrode capacitance of around 62 F g(-1), determined by cyclic voltammetry in an aqueous electrolyte. Using an ionic liquid (IL) electrolyte, the estimated energy density increased from 0.003 to 1 Wh kg(-1), after introducing the CAG into the carbon fiber fabric. 'Proof-of-concept' multifunctional structural supercapacitor devices were fabricated using an IL-modified solid-state polymer electrolyte as a multifunctional matrix to provide both ionic transport and physical support for the primary fibers. Two CAG-impregnated carbon fabrics were sandwiched around an insulating separator to form a functioning structural electrochemical double layer capacitor composite. The CAG-modification not only improved the electrochemical surface area, but also reinforced the polymer matrix surrounding the primary fibers, leading to dramatic improvements in the matrix-dominated composite properties. Increases in in-plane shear strength and modulus, of up to 4.5-fold, were observed, demonstrating that CAG-modified structural carbon fiber fabrics have promise in both pure structural and multifunctional energy storage applications.
authors.affiliation: The Composites Centre, Imperial College London, London, United Kingdom. hui.qian@imperial.ac.uk
authors.forename: Hui
authors.initials: H
authors.lastname: Qian
authors.forename: Anthony R
authors.initials: AR
authors.lastname: Kucernak
authors.forename: Emile S
authors.initials: ES
authors.lastname: Greenhalgh
authors.forename: Alexander
authors.initials: A
authors.lastname: Bismarck
authors.forename: Milo S P
authors.initials: MS
authors.lastname: Shaffer