Absorbency of separators under compression

Separator absorption is an important parameter in batteries of all chemistries. The ability of a separator to absorb, hold, and release electrolyte affects cell performance, particularly in areas of rate capability. To quantify separator absorption, a gravimetric absorbency tester was developed as a possible characterization tool. The absorptive characteristics of separators were tested in uncompressed and compressed states. Total mass absorption and absorption rate data were collected. Volume changes (under ambient and high-pressure environments) were also noted.