In our previous work , in order to model the graphene-electrolyte interface, we adopted a simple QM/MD scheme consisting of one electrode in contact with the electrolyte. In two independent simulations this electrode was then charged positively and negatively to capture the behaviour of the anode and cathode. However, this setup increases the computational cost as two independent simulations are necessary. Additionally, this places further constraints on the simulations that may be carried out. In order to preserve overall net charge neutrality, the composition of the electrolyte must be augmented with additional ions to counter balance the charge of the electrode. Moreover, to avoid further complications, this means that the total electrode charge can only be incremented in integer multiples of the counter ionic charge. To this end, here we have implemented a two-electrode QM/MD setup, which alleviates all of these constraints and enables us to simultaneously sample the interface at the anode and cathode. From a practical standpoint, the procedure for the two-electrode setup is analogous to the single electrode case of our previous work. In two separate QM calculations, the anode and cathode electronic structures are computed in the presence of the background electrostatic potential of the electrolyte atoms. This yields a set of atomic charges (computed via Mulliken population analysis) for each electrode. These atomic charges are mapped onto the classical MD force field and used for time evolution of the electrolyte. After a fixed timestep of 5 ps, the QM charges on the electrode are re-evaluated. The QM/MD simulation of each model is carried out for 160 ns, with the first 10 ns dedicated to system equilibration.