摘要 |
A cross-linked microporous polysulfone or polysulfone copolymer battery electrode separator membrane are described. Such membranes, which would otherwise be soluble above a particular, generally high temperature in selected battery electrolyte systems, once at least in part cross-linked, swell in the electrolyte at the particular higher temperature instead of dissolving. When the membrane separators are restrained between solid electrodes in a battery, the separator cannot increase in bulk volume, and the swelling occurs within the pores with the pore volume decreasing from its original bulk volume. The drop in pore volume causes the battery current density to drop, thereby reducing the heat generation within the hot area of the battery. This process provides a measure of safety against overheating and fires, and the battery is capable of continued usage if the overheating is localized.
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