WORLDWIDE TRENDS IN BATTERY SEPARATOR TECHNOLOGY AND USAGE

This paper reviews trends in battery separator usage for starting-lighting-and-ignition (SLI), motive power, and sealed valve-regulated lead/acid batteries. For SLI batteries, the dominant trend in the USA and Western Europe has been a dramatic increase in polyethylene envelope separator usage, with other countries now following this trend. This is at the expense of traditional leaf-type separators such as cellulose or sintered polyvinyl chloride (PVC). For motive power applications, several different types of separator materials are currently favoured, including polyethylene, microporous rubber, microporous PVC and resin-impregnated polyester fibres. Worldwide trends in the motive power battery and separator market are shown. For sealed valve-regulated lead/acid batteries, the favoured construction uses a recombinant battery separator mat, normally of 100% borosilicate glass (binder free). Alternative mats containing a proportion of polymeric fibres are now being investigated. Market trends and factors affecting growth in the use of recombinant battery separator mats (RBSM) are reviewed. Results of mercury-intrusion porosimetry data for different separator materials are shown and reviewed. This technique provides an interesting way of differentiating between different separator materials based on their pore size distributions.