Electrodeposition of tin(II) from citrate complexes

摘要

This paper provides the calculation of the distribution of the concentrations of complex particles of the Sn(II) - citrate - water system in the solution volume, on the surface of the electrode, and in the diffusion layer for the tin citrate electrolyte containing an excess of the ligand. Based on the calculations for the electrodeposition of tin, an electrolyte containing [SnCit]$^{2-}$ complex at pH 8.0 was chosen. The kinetic parameters of the discharge stage, the diffusion coefficient of the electrochemical active ion, and the current efficiency of tin were determined by the methods of stationary voltammetry and chronovoltamperometry. It is shown that the electroreduction of tin is governed by the laws of mixed kinetics and the transfer stage of the second electron is the limiting one. The discharge mechanism and the composition of the electroactive complex, which is [SnCit]$^{2-}$, are proposed. The current density of the deposition of tin coatings with different functional properties is determined as protective coatings and coatings of anodes of Li-ion accumulators.