Microcapillary battery separator including hollow fibers, and storage battery incorporating same

Abstract

A battery separator, for placement between conductive plates within a battery, includes a non-woven fiber mat made up of one or more nonwoven fibers, which have a specific cross-sectional shape and exhibit a microcapillary action. The fibers are preferred to be made of a thermoplastic selected from the group consisting of polyolefins, fluoropolymers, polyimides, polysulfones, polyesters, polyamides, and mixtures thereof Each of the fibers includes an outer surface, a hollow internal cavity, and an extended slot. The hollow internal cavity communicates with the outer surface by way of the extended slot. Capillary forces within the fibers are greater than those on the fiber surface, such that a liquid electrolyte readily moves through the interior of the fiber via a wicking action. As a result, the battery separator tends to direct fluid to adjacent battery plates even when an electrolyte level, within the battery, drops below the tops of the plates.

Dependencies are inferred from the claim text.