mass transfer coefficient in electrochemistry

The heterogeneous diffusion rate constant defined for the case of the limiting current. A more general definition in terms of the electrode current densities is:

$k d = j ν n F ( c e − c 0 )$

$k d = j ν ( 1 − t B n ν −1 z B −1 ) n F ( c e − c 0 )$

where $j$ is the electrode current density, $ν$ is the stoichiometric number, $n$ is the charge number of the electrode reaction, $F$ is the Faraday constant, $c e$ is the interfacial concentration, $c 0$ is the bulk concentration, $t B$ is the transport number of species B, and $z B$ is the charge number of species B.

Source:

PAC, 1981, 53, 1827 (Nomenclature for transport phenomena in electrolytic systems) on page 1839