SYNTHESIS AND ELECTROCHEMICAL PERFORMANCES OF TRIBASIC AND TETRABASICLEAD SULFATES PREPARED BY REACTIVE GRINDING

Tribasic lead sulfate (3BS) and tetrabasic lead sulfate (4BS), used as precursors of the positive active material in the lead/acid batteries , were prepared by a new method: reactive grinding. The effects of var ious experimental parameters (stoichiometry, hygrometry of the startin g compounds, duration of mechanical treatment) upon the nature and mor phological features of the resulting phase were investigated. Among th em, hygrometry turned out to be the most critical one. With water in e xcess, only 3BS was produced while dry reagents led to 4BS. In both ca ses, samples with a small particle size and high reactivity were obtai ned. In order to evaluate the influence of the morphology upon the ele ctrochemical performances of such grinding produced samples, the capac ity was measured and compared with that of traditional 3BS and 4BS sam ples. (C) 1998 Published by Elsevier Science S.A.