Graphene/Aramid Nanofibers Composite Electrodes for Structural Energy and Power

Flexible electronics, such as roll-up displays and wearable systems have been widely studied with the fast increasing demand for potable electronics. For these flexible, portable electronics, structural elements which can bear mechanical load and dissipate mechanical stress are required in the energy storage systems such as lithium ion batteries and supercapacitors. Flexible graphene or graphene oxide papers have attracted much attention as structural electrodes due to their extraordinary mechanical and electrical properties. The mechanical properties and the electrochemical performance of the graphene paper electrodes can be manipulated when combined with guest materials. In this presentation, we report on the composite paper electrodes containing graphene oxide and aramid nanofibers fabricated by flow-directed assembly. Recently developed aramid nanofibers, well-known for its high mechanical strength, have been used as the guest material for creating composites. The addition of the aramid nanofibers produced flexible, mechanically robust electrodes, where aramid nanofibers act as the guest material and interfacially interact with graphene sheets. In addition, the incorporation of the guest material increased porosity and alleviated the diffusion limitation for application as electrodes for supercapacitors. The composition, morphology, and the structure of the paper were characterized using scanning electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy. Mechanical and electrochemical performances of the composite electrodes were explored as structural electrodes.