We present a quantitative characterization of the kinetics of silver deposition during electrophysical ionization (EPI), focusing on the roles of electric field strength E and interelectrode gap d. Series Δm(E) were obtained for d=1.5, 2, 3 cm. For small gaps, the yield exhibits a smooth, sigmoid-like increase followed by saturation (a plateau); at d=3 cm the curve becomes nonmonotonic—a pronounced maximum is followed by a decline—indicating a switch in the dominant mass-transfer step. The interpretation is developed within a steady-state formulation of the Nernst–Planck equations with a Robin (mixed) boundary condition at the cathode and a phenomenological “active-surface availability” factor η(E). It is shown that a decreasing η(E) adequately describes monotonic regimes, whereas for large d realistic reproduction of the peak and subsequent drop is achieved by introducing a peaked η(E) or a weak field dependence of the external mass-transfer coefficient kc(E). This behavioral shift is consistent with morphological evolution of the deposit—from a compact structure to a dendritic–porous one with a self-screening effect. The dimensionless drift parameter β=zFEd/RT and the Damköhler number Da=kcd/D define a regime map that orders the series by d and delineates the “operating window” for E. Practically, this implies maintaining the field near its optimum, providing gentle hydrodynamic mixing and thermal stabilization (particularly at d≥3 cm), and structurally suppressing field focusing. The results provide a basis for scaling EPI and for adaptive control of silver deposition.