PHYSICAL CHANGE IN POSITIVE-PLATE MATERIAL - AN UNDERRATED CONTRIBUTOR TO PREMATURE CAPACITY LOSS - DISCUSSION

In spite of a broad and sustained research effort, premature capacity loss (PCL) remains the major barrier to the long term usage of lead/ac id batteries in a range of demanding applications. Of greatest concern today is the manifestation of PCL that results in failure of the poro us component of the positive plate. While much of the previous work in this area has focussed on the localized interactions between constitu ent particles of the porous material, we suggest that important bulk f actors, such as plate compression and apparent density, have not recei ved sufficient consideration. Indeed, evidence from experimental studi es indicates that apparent density is the critical determinant of posi tive-plate performance and that compression is the primary means by wh ich density is controlled in contemporary plate designs. Moreover, the extension of positive-plate cycle life depends on maintaining apparen t density above a minimum value. In light of this relationship, we pre sent strategies by which gains in plate performance can be achieved.