In this talk I will introduce some issues connected with the simulation of electrified interfaces at the nanoscale focusing on simulating the effect of an applied potential to an electrode, using realistic models for the charged electrode electrolyte interface. I will present some recent progress in the simulation of the double layer of fundamental solid liquid interfaces of interest for corrosion and water splitting, and its response to changes of potential applied to the cell [1]; this is obtained applying a general ab initio electrode-charging approach we developed.[1] R. Khatib, A. Kumar, S. Sanvito, M. Sulpizi and C. S. Cucinotta*, The nanoscale structure of the Pt-water double layer under applied potential revealed, 2021, 391, 138875 In this talk I will introduce some issues connected with the simulation of electrifiedinterfaces at the nanoscale focusing on simulating the effect of an applied potential to an electrochemical (EC) cell, using realistic models for the charged electrode electrolyte interface. I will present some recent progress in the simulation of the double layer of the fundamental solid liquid interfaces of interest for corrosion and water splitting and its response to changes of potential applied to the cell [1]; this is obtained applying a general ab initio electrode-charging approach we developed.[1] R. Khatib, A. Kumar, S. Sanvito, M. Sulpizi and C. S. Cucinotta*, The nanoscale structure of the Pt-water double layer under applied potential revealed, 2021, 391, 138875