Preparation and performance of aramid nanofiber membrane for separator of lithium ion battery

ABSTRACT Stable and uniform dispersions of para ‐aramid nanofibers have been prepared by adding methoxypolyethylene glycol (mPEG) in the polymerization process, followed by strong shear and dispersion. Aramid membranes are fabricated by vacuum‐assisted filtration of the nanofiber dispersion and assembled into batteries as separator. The membrane properties and battery performances are characterized in detail and the effect of mPEG content on these properties is explored. It is demonstrated that aramid membranes possess good electrolyte wettability, excellent mechanical properties, and superior thermal stability, which improve the safety of lithium ion batteries. The mPEG is critical to the formation of aramid nanofibers and improves the porosity and ionic conductivity of the membranes. These fascinating characteristics and facile papermaking method endow aramid membrane potential application as separator in lithium ion batteries with superior safety. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133 , 43623.