Highly Multifunctional Dopamine-Functionalized Reduced Graphene Oxide Supercapacitors

Batteries and supercapacitors that possess the mechanical properties of structural composites are desirable for electric vehicles and aerospace applications, as energy may be stored within structural panels to realize significant mass and volume savings. However, current electrode materials suffer from poor mechanical performance, as described by a low multifunctional efficiency parameter (<1). This parameter is a single metric that combines mechanical and electrochemical performance, whereby a higher value represents improved multifunctionality. Here, the interplay between chemistry and mechanics is harnessed to design reduced graphene oxide (rGO) structural supercapacitor electrodes via hydrogen bonding and chelation inspired by nacre. Dopamine functionalization, divalent ions, and aramid nanofibers create rGO composite electrodes with high multifunctional efficiency values of 5-13.6. Non-covalent interactions lead to increases in Young's modulus and ultimate tensile strength of 220% and 255%, respectively, as compared with pure rGO. This work highlights the importance of chemical interactions for realizing multifunctional structural electrodes.