Weppner and Huggins [1] were the first to develop relations to determine the diffusion coefficient from the measurement of a system response to a potential or current step, in the case of semi-infinite linear diffusion of the species produced or consumed at the electrochemical interface.
We will first present a simple approach that is valid in the case of an insertion reaction, with restricted linear diffusion, using long time responses [2]. After exposing the limitations of this first method, we will show how it can be applied in the presence of non-negligible ohmic drop, charge transfer resistance and double layer capacitance. The results of each method are compared with those obtained by electrochemical impedance spectroscopy.

[1] W. Weppner, R. A. Huggins, Determination of the kinetic parameters of mixed-conducting electrodes and application to the system Li3Sb, J. Electrochem. Soc. 124 (10) (1977) 1569–1578.

[2] C. Montella, Apparent diffusion coefficient of intercalated species measured with PITT: A simple formulation, Electrochimica Acta 51 (15) (2006) 3102 – 3111.