This invention relates to the field of battery separator materials technology, specifically to MXene-functionalized
aramid paper-based battery separators, their preparation methods, and applications. Meta-
aramid paper is prepared by wet
papermaking using short-
cut meta-
aramid fibers and precipitated fibers. MXene nanosheets are prepared by
hydrofluoric acid etching. Using the meta-aramid paper as a substrate, a functional
coating is constructed on the surface of the aramid paper by loading a mixture of para-aramid nanofibers and MXene through a vacuum-assisted
filtration-layer-by-layer self-
assembly method. The resulting functionalized separator is obtained through
protonation reduction. The separator, with its three-dimensional porous protective layer constructed from para-aramid nanofibers and MXene, combines
physical barrier and chemical bonding, effectively inhibiting
polysulfide shuttle. Furthermore, the highly active sites of MXene can activate
inert sulfur-containing substances, improving
sulfur utilization. When used in assembling
lithium-
sulfur batteries, the separator achieves an initial
discharge capacity of 1244 mAh·g at a
constant current density. ‑1 The capacity
retention rate is 82% after 200 cycles.