The recently developed polarized electrochemical vapor deposition (PEVD) is a process which actively uses mass and charge transport within Wagner's electrochemical tarnishing theory for product formation. Since the migration of charged ionic and electronic carriers during PEVD is a kinetic process, it is imperative to solve the PEVD reaction rate-limiting steps for samples undergoing both stage I and SI growth. The PEVD process for Na2CO3 auxiliary phase deposition at the working electrode of a potentiometric CO2 sensor was selected for the current solid electrolyte cyclic voltammetry studies. The results from this investigation not only confirm the previous steady-state potentiostatic studies for samples undergoing stage II growth, but also reveal qualitatively the kinetics of the PEVD reaction and subsequent product formation in a PEVD system during stage I growth. At lower temperatures and working electrode overpotentials, the PEVD reaction rate-limiting step is the charge transfer reaction. At higher temperatures and lower working electrode overpotentials, the rate-limiting step is the diffusion of Na+ across the product. At higher working electrode overpotentials for all temperatures, the rate-limiting step is the surface diffusion of neutral reactants.