How Ohmic Resistance Shapes Your Voltammogram

The iR drop , also known as the ohmic drop , refers to the reduction in effective potential at the working electrode interface due to the resistance of the electrolyte solution. This drop affects both the potential applied by the potentiostat and the potential it measures, thereby distorting the observed electrochemical response. In the absence of mass transport limitations, the redox reaction can be modelled using an equivalent electrical circuit that describes the interfacial behaviour between the reference and working electrodes: Here: R s – the solution resistance (also known as the electrolyte or uncompensated resistance). R ct – the charge transfer resistance, associated with the kinetics of the electron transfer reaction. C dl – the double-layer capacitance, representing the electrochemical double layer at the electrode interface. The potentiostat continuously regulates the potential difference between the reference ...