On the impedance of the gassing reactions in lead-acid batteries

Oxygen and hydrogen evolution reactions in flooded lead-acid batteries duri ng float charging were studied by galvanostatic steady-state polarization a nd impedance spectroscopy techniques. Given the very low relaxation frequen cies of such processes (between ? and 0.05 mHz), impedance measurements nee ded to he extended to the ultra-low frequency domain. Investigation of thei r dynamic behavior provided a complete description of the porous character of the active zone. The steps involved in the reaction mechanisms are also discussed. (C) 2001 Elsevier Science B.V. All rights reserved.