Reaction model development for the Pb/PbSO4 system

Metal dissolution, active-passive transition and passive layer electroreduction reactions taking place during discharge/charge processes in the lead/sulfuric acid system are discussed on basis of data obtained from steady-state polarizations, potentiostatic pulses, single (STPS) and repetitive (RTPS) triangular potential sweeps, modulated voltammetry, complex voltammetry combined with potentiostatic steps, and electrochemical impedance spectroscopy, using rotating ring (Pb)-disc (Pb) electrode assembly, as well as scanning electron microscopy (SEM). Data analyses derived from transient electrochemical techniques employing parametric identification procedures, non-linear fit routines and computer simulations have been interpreted in terms of appropriate nucleation and growth models for the formation of new phases, in which the characteristics and properties of the compounds generated on the Pb electrode surface exhibit a remarkable dependence on the operational potential.