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 vacuumassisted 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.

Nanoporous aramid nanofibre separators for nonaqueous redox flow batteries

“…More recently, aramid nanofibres (ANFs) have emerged as a new nanoscale building block 43 , 44 . Composites prepared from ANF possess biomimetic nanofibre “skeleton” reminiscent of nanofibre networks found in soft tissues have demonstrated superior mechanical properties and high thermal stability 43 , 45 – 51 owing to the parent aramid fibers, well-known under the tradename Kevlar TM . Furthermore, ANF composites developed for lithium-ion batteries have demonstrated dendrite-suppressing capabilities due to a combination of high mechanical strength and nanoporosity 48 , 49 , 51 .…”

The bottom‐up synthesis for aramid nanofibers: The influence of copolymerization

“…[4] Retaining the excellent mechanical properties, ANFs have high-specific surface area and good dispersibility in solvent, which can be easily used to fabricate functional nanocomposites as a kind of nanoscale building block. [5,6] For example, ANFs have been used to construct battery separators exhibiting excellent performances, [7][8][9][10] aramid papers with high-mechanical strength and great thermal stability for high-grade insulation demands, [11] nanocomposites with the incorporation with graphene or multiwalled carbon nanotubes, and many other functional materials. [12][13][14][15][16] ANFs have also been applied in the fabrication of organic aerogels with high porosity, low density, and great thermal stability.…”

“…The polymerized product can be directly converted into nanofibers in an aqueous dispersion while the tedious macrofiber formation and chemical cleavages are totally avoided. [10,34] However, in the previous method, polyoxyethylene ether was employed as an interfacial tailoring additive to facilitate the nanofiber formation in dispersion. Its possible residual in the final products would be a drawback to the application performances.…”

Fabrication 3d Tissue Engineering Scaffold Poly(Ethylene) Diacrylate Filled with Aramid Nanofiber: Mechanical Evaluation and Toxicity

“…Kevlar is a well-known macroscale synthetic para-aramid fiber with a high tensile strength-to-weight ratio. Typical Kevlar threads and fibers consist of lengthy molecular chains made of poly (paraphenylene terephthalamide) (PPTA) between which there are interchain bonds making the material highly strong and rigid with a tensile strength of 3.6GPa and modulus comparable as carbon nanotube (CNT) fibers [34], [35]. By dissolving in dimethylsulfoxide (DMSO), aramid macroscale fibers can be divided into nanofibers in the presence of potassium hydroxide (KOH) [35].…”