Preparation of high safety self-assembled aramid-based nanofiber separator and its application in lithium metal batteries

A novel, simple and successive process, which aims at coating the covalently crosslinked p-phenylene terephthamide (PPTA) onto commercial polypropylene (PP) separators, has been demonstrated. Without any additional binder, the PPTA nanofiber coating layer sticks to the porous PP separators by physical anchoring, endowing the composite separators with modified wettability toward electrolytes and heat resistance.

Meanwhile, migration routes for lithium ions are guaranteed by the porous structure controlled by the self-assembly of the fibrillar units during the nonsolvent induced phase separation. The designed PPTA/TAB@PP separator shows a high lithium-ion transference number of 0.65. As a result, the symmetric Li//Li cell utilizing this separator demonstrates stable lithium plating and stripping.