Simplified methods for determining the ionic resistance in a porous electrode using linear voltammetry

Two simplified methods are proposed for determining the internal ionic resistance of a porous electrode using linear voltammetry in the double layer region. With the 70% current response time t0.7 on linear voltammogram and the independently measured uncompensated solution resistance Re, the internal ionic resistance of a porous electrode can be calculated using the equation Rp=2.483t0.7/Ctotal−2.989Re, where Ctotal is the total capacitance of the porous electrode and can be deduced from the plateau current on the voltammogram. When Rp is not much smaller than Re, it is also possible to estimate the ionic resistance according to the curve shape of the linear voltammogram without knowing Re.