Electrochemical characterisation of expander materials

A method is proposed for the characterisation of expander materials based o n the comparison of the results of three different electrochemical techniqu es: electrochemical impedance, cyclic voltammetry and potentiostatic transi ents. The evaluation of the expanders performance carried out on the basis of the results of such techniques takes into account different important ac tions of the organic additives such as adsorption on lead and the kinetics of electrochemical reactions, which are all very important for the practica l behaviour of the expanders in the negative plate of the lead-acid battery . The need of clarifying possible correlations between chemical characteris ation and electrochemical tests is shortly discussed. This last point is ma inly focused on the understanding of the action of the functional groups wh ich are present in the organic molecules. (C) 2001 Elsevier Science B.V. Al l rights reserved.