| Popis: |
Structural energy storage is a field associated with the combination of important functions such as structural reliability, energy storage, and energy delivery. The combination of said functions ensures savings in the overall volume and mass of the system. Reduced graphene oxide (rGO) and aramid nanofibers (ANF) composite film electrodes were developed for the purpose of structural energy storage. Graphene is studied due to its remarkable mechanical properties, electrical conductivity and electrochemical surface area. Furthermore, Kevlar® aramid nanofibers enhance the structural properties of the composite due to their excellent mechanical properties. However, external strains are expected on the composite film due to its structural function, and the response of the electrical properties to external strain needs to be evaluated. In this work, the change in electrical resistance was measured under bending-induced strain, using a home-built instrument that allows for accurate strain measurements using image analysis. We show that the resistance of the film decreases under bending via a mechanism we called “mechanical annealing.” This mechanism may be the effect of improved stacking of rGO sheets. The degree of mechanical annealing was also correlated to the amount of bending strain, as well as the amount of ANF loading. Our results demonstrate an improvement, rather than deterioration of the electrical resistance of rGO/ANF composite films under strain, making them suitable for structural energy storage applications. |
