Performance of supercapacitors containing graphene oxide and ionic liquids by molecular dynamics simulations

Graphene oxide (GO) has been widely considered for electrochemical energy storage applications due to its improved physical, chemical, and electronic properties over pure graphene. The oxygenated groups adsorbed on the surface of the GO lead to greater ionic mobility, and greater density of states while maintaining the same specific area of pure graphene. In parallel, the morphology of the electrode, structured in the form of pores, has a huge impact on the device's properties by favoring electrode-electrolyte interactions, expanding the contact area between the two. Although there is already a considerable volume of computational work on the performance of graphene oxide electrodes as well as on porous carbon electrodes, the combined analysis of both effects (the chemical functionalization and the porous morphology) in a single device to mimic a supercapacitor has not yet been presented. In this work, atomistic molecular dynamics simulations were performed to study the structural aspects of porous graphene oxide electrodes in three different ionic liquids held under constant potential. In addition, a detailed description of the electrode charging mechanisms in the presence of each of the electrolytes is presented.