where R 0 is the Ohmic resistance, R p the polarization resistance, γ(τ ) with ∞ 0 γ(τ )dτ = 1 is the distribution function used to fit the impedance data, and i = √ -1 is the imaginary unit. Such an inversion has been theoretically shown to be mathematically possible for data of any non-oscillating electrical system . However, a direct physical interpretation is primarily viable for an impedance response of RC or ZARC features.