On the impedance plane displays for irreversible electrode reactions based on the stability conditions of the steady-state—I. One state variable besides electrode potential

It is shown that the Faradaic admittance under potentiostatic control can be expressed as: based on the stability condition of steady-state for an irreversible electrode process whose rate depends upon electrode potential E and one other state variable which varies with E. Here Rt and a take positive values. A capacitive or an inductive component will be involved in the Faradaic impedance depending upon whether B is negative or positive respectively. When B < 0, there will be three different modes of impedance plane displays depending upon whether a − Rt|B| is greater than, less than or equal to zero.