Nonwoven Membrane Research Articles

Morphological changes in purulent wound defect of the oral mucosa when using a non-woven polymer membrane with vancomycin (experimental study)

Currently, the problem of effective treatment of purulent wounds of the oral mucosa is relevant, scientists are improving dressing materials, creating new coatings. The study tested for the first time a non-woven polymer membrane from a copolymer of vinylidene fluoride with tetrafluoroethylene with Vancomycin, presumably which will meet the requirements of an ideal dressing material. The purpose of the study is to determine the effect of a non-woven polymer membrane with Vancomycin on the regeneration of a purulent wound defect of the oral mucosa in experiment. 35 white Wistar rats were divided into three groups: first group (n = 15), in which the wound defect was left open according to the standard procedure of the wound process in the oral cavity; second group (n = 15), in which the wound defect was covered with a non-woven polymer membrane with Vancomycin; third group (served as control group), in which the rats had intact oral mucosa (n = 5). Tissue samples were collected from the area of the purulent wound on the 3rd, 7th and 14th days of the study and histological sections were prepared using a standard procedure. The indicators were calculated using the AxioVision SE64 Rel program. 4.9.1: area of loose fibrous connective tissue (%), cellular infiltration (%), granulation tissue (%).The statistical analysis of the obtained data was performed using Mann–Whitney and Wilcoxon tests in Statistica 8.0 (StatSoft, USA) software. Differences were considered statistically significant at p 0.05. It has been established that the non-woven polymer membrane from a copolymer of vinylidene fluoride with tetrafluoroethylene with Vancomycin has a beneficial effect on the regeneration of the oral mucosa in the postoperative period and reduces scar changes in the later stages of healing.

Improvement of Sound-Absorbing Wool Material by Laminating Permeable Nonwoven Fabric Sheet and Nonpermeable Membrane

Thin sound-absorbing materials are particularly desired in space-constrained applications, such as in the automotive industry. In this study, we theoretically analyzed the structure of relatively thin glass wool or polyester wool laminated with a nonpermeable polyethylene membrane and a permeable nonwoven fabric sheet. We also measured and compared the sound-absorption coefficients of these samples between experimental and theoretical values. The sound-absorption coefficient was derived using the transfer matrix method. The Rayleigh model was applied to describe the acoustic behavior of glass wool and nonwoven sheet, while the Miki model was used for polyester wool. Mathematical formulas were employed to model an air layer without damping and a vibrating membrane. These acoustic components were integrated into a transfer matrix framework to calculate the sound-absorption coefficient. The sound-absorption coefficients of glass wool and polyester wool were progressively enhanced by sequentially adding suitable nonwoven fabric and PE membranes. A sample approximately 10 mm thick, featuring permeable and nonpermeable membranes as outer layers of porous sound-absorbing material, achieved a sound-absorption coefficient equivalent to that of a sample occupying 20 mm thickness (10 mm of porous sound-absorbing material with a 10 mm back air layer).

Preliminary investigation of nanofibrous membranes for sound absorption

Nanofibrous membranes show interesting mechanical properties, low thickness and lightness, besides the possibility of using a great variety of polymers. The electrospinning technique makes possible the production of polymeric random nanofibres to form nonwoven membranes, which are currently used in several application fields, such as filtration, biomedicine, biomechanics, electronics, and composite materials. Their application in the automotive and aerospace engineering field could bring significant benefits to the acoustic comfort design. However, their acoustics properties still need to be further assessed. This study investigates the acoustic absorption of electrospinning-made nanofibrous membranes in Nylon 66 with different fibre diameters and mat thicknesses. Morphological and thermal characterisation of the electrospun membranes have been assessed via Scanning Electron Microscope (SEM) and Differential Scanning Calorimetry (DSC), respectively. The acoustic absorption characteristics of various samples changing fibre diameter, membrane thickness and mounting conditions were tested in the impedance tube. The results showed more relevant acoustic absorption properties in the nanofibrous membrane coupled with a polyester fibre. Further studies will clarify if filament direction and constituent material can be improved for a more durable and resistant membrane application.

Electrospun Polyvinylidene Fluoride Membranes: Waterproofing and Acoustic Performance for Air and Acoustic Vents in Electronics.

Advancements in electronic devices demand materials capable of exceptional performance in various challenging environments. This study presents polyvinylidene fluoride (PVDF) nonwoven membranes with controlled porosity, created using an air-guided electrospinning method, followed by a calendaring process. These membranes exhibit a combination of water-repellent properties and sound transmission capabilities, making them ideal candidates for use in air and acoustic vents in electronic systems. A key feature of our membrane is the three-dimensional nanostructured pores, ranging from 0.20 to 0.76 μm, with a mean pore size of 0.51 μm, achieved through the formation of randomly arranged long nanofibers. By employing both experimental and theoretical methods, we achieved impressive performance metrics: air permeability of 0.86 cm3/cm2/s, water contact angles up to 139.3°, and breakthrough pressure as low as 0.27 MPa. Our PVDF nonwoven membranes maintain an optimal balance of stiffness, density, and air permeability, leading to exceptionally low sound transmission loss values ranging between -10 and -40 dBV/Pa, all while preserving their structural integrity. These findings contribute to the development of next-generation waterproof and acoustically permeable membranes, offering enhanced performance capabilities in demanding operational scenarios. This work advances the field of nanomaterials, environmental engineering, and acoustic technologies, with the potential to influence the design of future electronic devices.

Novel three-dimensional live skin-like in vitro composite for bioluminescence reporter gene assay.

We genetically manipulated HaCaTcells, a spontaneously immortalised normal keratinocyte cell line, to stably express two different coloured luciferase reporter genes, driven by interleukin 8 (IL-8) and ubiquitin-C (UBC) promoters, respectively. Subsequently, we generated a three-dimensional (3D) skin-like in vitro composite (SLIC) utilising these cells, with the objective of monitoring bioluminescence emitted from the SLIC. This SLIC was generated on non-woven silica fibre membranes in differentiation medium. Immunohistochemical analyses of skin differentiation markers in the SLIC revealed the expression of keratins 2 and 10, filaggrin, and involucrin, indicating mature skin characteristics. This engineered SLIC was employed for real-time bioluminescence monitoring, allowing the assessment of time- and dose-dependent responses to UV stress, as well as to hydrophilic and hydrophobic chemical loads. Notably, evaluation of responses to hydrophobic substances has been challenging with conventional 2D cell culture methods, suggesting the need for a new approach, which this technology could address. Our observations suggest that engineered SLIC with constitutively expressing reporters driven by selected promoters which are tailored to specific objectives, significantly facilitates assays exploring the physiological functions of skin cells based on genetic response mechanisms. It also highlights new avenues for evaluating the physiological impacts of various compounds designed for topical application to human skin.

Long-term operation and dynamic response of dissimilatory nitrate reduction to ammonium process under low-frequency infrared electromagnetic field

Dissimilatory nitrate reduction to ammonium (DNRA) received more attention for its ability to recover ammonium. This study investigated the possibility of low-frequency infrared electromagnetic field (IR-EMF) to improve DNRA. The optimal IR-EMF intensity of 0.04 μT could effectively improve DNRA activity of nonwoven fabric membrane bioreactors. In the long-term operation, the average ammonium conversion efficiency was enhanced by 117.7% and 62.5% under 0.04 μT and 0.06 μT IR-EMF, respectively. The highest nrfA-gene abundance and potential DNRA rate were obtained under 0.04 μT IR-EMF exposure. Bacteroidetes fragilis, Shewanelle oneidensis MR-1, and Thauera sp. RT1901 were selected to investigate the dynamic response of nitrogen transformation and energy metabolism to IR-EMF. The transcriptome sequencing and RT-qPCR results suggested that IR-EMF could enhance both denitrification and DNRA process, mainly by improving ATP synthesis to boost metabolic activity. This study provided an efficient method for the nitrogen recovery via DNRA process by applying IR-EMF.

A facile method for continuous production of temperature-adaptive hyperthermal management core-sheath polyurethane nanofiber yarns based on vanadium dioxide toward commercialization

As a facile method for producing nanofiber materials, electrospinning is widely used in various fields. However, it is generally adopted for fabricating nonwoven nanofiber membranes, which limited its applications. In this study, we propose a new facile mechanism for continuous production of high-strength electrospinning nanofiber-covered yarns, which can be directly used for fabric weaving toward commercialization. After doping of vanadium dioxide(VO2), a solid–solid phase change material (PCM) with a phase change temperature close to room temperature, a smart nanofiber-covered yarn with hyperthermal management capability is obtained. Benefiting from the delicate core-sheath structure and rigorous adjustment of spinning solution composition as well as spinning parameters (including spinning voltage, solution flow rate, and spinning distance), it achieved optimal nanofiber diameter at 510 nm, and patterns sewn on polyester fabric can be lowered by up to 19 °C compared to polyester fabric. The nanofiber-covered yarn can be used for textiles such as garments and curtains, which helps reduce the tremendous energy consumed for thermal regulation.

Solution Blow Spinning of the Benzimidazole-Containing Aramid Nanofibers for Separators of Lithium-Ion Batteries.

Nanofibers based on high-performance polymers are much highlighted in recent studies toward advanced lithium-ion batteries. Herein, we demonstrate one scalable poly(ethylene oxide) (PEO)-assisted solution blow spinning strategy for the preparation of heterocyclic aramid (HA) nanofibers of poly(p-phenylene-benzimidazole-terephthalamide). The incorporation of PEO is essential to improve the spinnability of the HA solution achieved directly through the low-temperature-solution copolymerization process. Additionally, the flexible PEO with a strong H-bonding affinity is also utilized as the molecular zipper to adjust the pore size of the nanofiber membrane during the post-treatment process. The obtained membrane combines the good wettability of PEO to the liquid electrolytes, with outstanding mechanical strength, modulus, toughness, and environmental resistance of HA. The nonwoven separator membranes with a porosity of 83.6% exhibited excellent comprehensive performance, which could be seen not only on the high tensile strength (68.2 MPa), modulus (3.0 GPa), and toughness but also on the high thermal stability (Td > 405 °C) and flame retardancy, as well as the high electrolyte uptake (302.4%). The ion conductivity of the porous separators reached 0.83 mS/cm, with the bulk resistance dropping to 1/4 of the reference polypropylene separator. In the assembly of the Li/LiFePO4 half battery, the HA separators displayed improved discharge specific capacity and high retention in both rate capability and cycling tests, providing the potential industrial preparation for advanced lithium-ion batteries.

Adaptable intelligent filters based on nanotextured nonwoven membranes containing water-insoluble hydrogels

The work demonstrates, for the first time, thermo-responsive, water-insoluble, hydrogel-based, nano-fibrous filter media comprised of copolymers of N-isopropylacrylamide (NIPAM) and methyl methacrylate formed by electrospinning. Moreover, a comprehensive novel physical explanation of all aspects responsible for the physical mechanisms resulting in the thermo-responsive regulation of the water flow rate and an enhanced interception of nanoparticles by such filter membranes is given. They are the wettable-non-wettable transition, pore, and fiber-size changes, as well as a diminishing filter thickness at the lower critical solution temperature (LCST) of the copolymers developed here, which interplay with a significant reduction in the water viscosity with temperature. Poly(N-isopropylacrylamide) (PNIPAM) hydrogel is an attractive material because of its thermo-responsive properties. Its wettability changes with water temperature. This characteristic holds great promise for the development of advanced filter media and related responsive materials. In this study, PNIPAM hydrogels were designed and transformed into filter membranes for applications in water filtration in biomedical and other related systems. These thermo-responsive filter membranes offer the potential for enhanced filtration efficiency, selectivity, and the overall system performance. Here, two different procedures were adopted to form water-insoluble thermo-responsive filter media based on PNIPAM hydrogels. The PNIPAM-based hydrogels were electrospun, resulting in the formation of thermo-responsive water-insoluble nanofiber membranes. These membranes underwent a series of comprehensive experiments to assess their performance and characteristics, including mass loss, water droplets for the wettability assessment, filtration tests, shrinkage measurements, and microscopic observations. These diverse experiments yield a full understanding of the PNIPAM-based nanofiber membranes’ properties and their potential applications.

Janus Nanofiber Membranes with Photothermal‐Enhanced Biofluid Drainage and Sterilization for Diabetic Wounds

AbstractDiabetic wounds are difficult to heal, and the key to wound healing is exudate management and effective disinfection. Inspired by the asymmetric wettability of Janus‐structured lotus leaves, herein the study has presented the design of a biomimetic asymmetric Janus membrane that integrates unidirectional biofluid drainage and photothermal‐enhanced evaporation/sterilization capabilities for accelerating diabetic wound healing. This Janus membrane is prepared by electrospinning polyacrylonitrile (PAN) nanofiber membrane containing polydopamine (PDA) on the surface of polypropylene (PP) nonwoven membrane. Such PP/PANx%PDA Janus membrane enables antigravity “pumping” of the water from the hydrophobic PP layer to the hydrophilic PANx%PDA layer within 22 s through contact points on the Janus interface. The incorporation of 30 wt% PDA in PAN imparts high photoabsorption and photothermal responsiveness, facilitating continuous volatilization of the exudate, achieving twice the displacement of water, and causing irreversible damage to bacteria. As a result, it effectively alleviates inflammation and cellular fibrosis while promoting collagen deposition due to its structure and antibacterial properties. Impressively, such photothermal‐enhanced Janus membrane achieves an impressive closure rate of 96.7% for diabetic wounds, better than that of (59.8%) for conventional bandages. Therefore, this asymmetric Janus membrane offers a promising alternative for the healing of chronic diabetic wounds.

Impact of cellulose nanofibers on cellulose acetate membrane performance

Membranes find applications across a wide spectrum of industries, including water treatment, energy production, and biomedicine. In this study, nonwoven membranes were fabricated using cellulose acetate (CA) as the primary component, with varying percentages of cellulose nanofibers (CNFs) embedded as reinforcement. These CNFs were prepared through an oxalic acid pretreatment (Oxalic-CNFs). Their incorporation into electrospun membranes represents an innovative approach, enhancing their mechanical properties for applications subjected to high loads and improving its functionalization capabilities. The impact of Oxalic-CNFs on membrane properties was investigated at nanofiber loadings ranging from 0 to 18 wt%. Membranes produced with 6 wt% Oxalic-CNF exhibited the superior physical and mechanical properties. This improvement can be attributed to the formation of threads with higher intrinsic strength, a reduction in pore size, and an increase in density. When higher percentages of CNFs were added, the membranes were not properly formed, because filaments were not continuous and the needle became clogged. The substructure of the membrane proved to be a critical factor for mechanical properties, with remarkable increases in tensile strength and elastic modulus (around 300%) when comparing 4–6 wt% Oxalic-CNF-loaded membranes to CA membranes.

Fabrication of Air Conditioning Antimicrobial Filter for Electrically Powered Port Tractors via Electrospinning Coating

With the stricter emission regulations for internal combustion engines, electric vehicles, including electrically powered port tractors, have received increasing attention. However, currently, most of the filters used in electric vehicles are conventional membranes that only have the function of filtering particles and foreign objects. Therefore, in order to improve the above issues, the surface of commercial non-woven filter membranes was coated with Ag nanopowder nanofibers and AgNO3 nanofibers via electrospinning. At present, the comparative research on the antibacterial ability of Ag nanopowder and AgNO3 is still blank in the same research system, especially with the use of electrospun coating technology. The morphologies and structures of non-woven fabrics and electrospinning coated samples were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The characterization results indicate that both pure PVA and PVA composite fibers can be successfully coated on the surface of non-woven fabrics. The average diameter of all electrospun PVA composite fibers is distributed in the range of 470–700 nm. The PVA nanofibers with a low content of 1 wt% AgNO3 have good antibacterial properties against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), with clearance clear zones of inhibition of 26.00 mm and 17.30 mm, respectively.

Preparation of Nano-PbWO4 Particles by Polymaleic Acid Modification: A Highly Filled Nonwoven Membrane Used To Improve the Wearing Comfort and Radiation Safety of γ-ray Protection Products

Preparation of Nano-PbWO₄ Particles by Polymaleic Acid Modification: A Highly Filled Nonwoven Membrane Used To Improve the Wearing Comfort and Radiation Safety of γ-ray Protection Products

Hydrophobic fouling-resistant electrospun nanofiber membranes from poly(vinylidene fluoride)/polyampholyte blends.

This study reports the fabrication of non-woven fibrous membranes from electrospinning blended solutions of PVDF with polyampholytes in N,N-dimethylformamide and methanol. Polyampholytes are macromolecules that have both positive and negative charged units in different side groups attached to the backbone. In this study, we used a random polyampholyte amphiphilic copolymer (r-PAC) synthesized by co-polymerizing a hydrophobic monomer in addition to the positive and negative charged monomer units, to reduce the fouling propensity of PVDF electrospun membranes while preserving its inherent hydrophobicity. Blends of PVDF/r-PAC were electrospun across the full range of compositions from 0/100 to 100/0. Scanning electron microscopic analysis showed formation of beaded fibers with average fibril diameters from 0.09-0.18 μm. The variation in the fiber diameters is caused by the change in surface charge density, dynamic viscosity of the solution, and the instability of the Taylor cone. Bead formation was observed in the mats electrospun from less viscous solutions. Wide angle X-ray scattering showed that electrospun fibers of PVDF crystallized into the electro-active β and γ crystal phases, whereas polyampholytes were amorphous. Thermogravimetry showed that the PVDF/r-PAC blends have a multi-step thermal degradation mechanism while PVDF homopolymer showed single-step thermal degradation. Sessile drop contact angle measurements confirmed that fibers possess high hydrophobicity and super-oleophilicity. Adsorptive fouling experiments with a fluorescently labeled protein confirmed that the fiber mats obtained from the PVDF/r-PAC blends resist protein adsorption, exhibiting highly enhanced fouling resistance compared to the fibers obtained from homopolymer PVDF.

Bio-based electrospun polyamide membrane – sustainable multipurpose filter membranes for microplastic filtration

Electrospun nonwoven membranes from bio-based PA 6.9 can serve as efficient filters for the removal of microplastic from water and air as well as for the remediation of oily wastewater.

Unveiling high-power and high-safety lithium-ion battery separator based on interlayer of ZIF-67/cellulose nanofiber with electrospun poly(vinyl alcohol)/melamine nonwoven membranes

Due to the poor thermal stability of conventional separators, lithium-ion batteries require a suitable separator to maintain system safety for long-term cycling performance. It must have high porosity, superior electrolyte uptake ability, and good ion-conducting properties even at high temperatures. In this work, we demonstrate a novel composite membrane based on sandwiching of zeolitic imidazole frameworks-67 decorated cellulose acetate nanofibers (ZIF-67@CA) with electrospun poly(vinyl alcohol)/melamine (denoted as PVAM) nonwoven membranes. The as-prepared sandwich-type membranes are called PVAM/x%ZIF-67@CA/PVAM. The middle layer of composite membranes is primarily filled with different weight percentages of ZIF-67 nanoparticles (x = 5, 15, and 25 wt%), which both reduces the non-uniform porous structure of CA and increases its thermal stability. Therefore, our sandwich-type PVAM/x%ZIF-67@CA/PVAM membrane exhibits a higher thermal shrinkage effect at 200 °C than the commercial polyethylene (PE) separator. Due to its high electrolyte uptake (646.8%) and porosity (85.2%), PVAM/15%ZIF-67@CA/PVAM membrane achieved high ionic conductivity of 1.46 × 10-3 S cm−1 at 70 °C, as compared to the commercial PE separator (ca. 6.01 × 10-4 S cm−1 at 70 °C). Besides, the cell with PVAM/15%ZIF-67@CA/PVAM membrane shows an excellent discharge capacity of about 167.5 mAh g−1after 100 cycles at a 1C rate with a capacity retention of 90.3%. The ZIF-67 fillers in our sandwich-type composite membrane strongly attract anions (PF6-) through Lewis' acid-base interaction, allowing uniform Li+ ion transport and suppressing Li dendrites. As a result, we found that the PVAM/15%ZIF-67@CA/PVAM composite nonwoven membrane is applicable to high-power, high-safety lithium-ion battery systems that can be used in electric vehicles (EVs).

An eco-friendly hydroentangled cotton non-woven membrane with alginate hydrogel for water filtration

Alginate hydrogel is highly efficient for water filtration due to its anti-fouling nature and formation of strong hydration membranes. However, poor mechanical properties of alginate hydrogel membrane limit its installation in water treatment. There is a need to enhance mechanical properties of alginate hydrogel membranes using eco-friendly, cost-effective materials and technologies. In this work, hydroentangled non-woven from cotton waste (comber noil) fibers was prepared. This non-woven was immersed in solution of sodium alginate (0.5 %, 1 %, 1.5 %) followed by dipping in calcium chloride solution which resulted in gel formation on and into cotton fibers. The successful formation of gel on non-woven fabric was confirmed through FTIR (Fourier transform infrared spectroscopy) and properties of this composite membrane were analyzed by SEM (Scanning electron microscopy), XRD (X-ray diffraction), DSC (Differential scanning calorimeter), water contact, water flux, oil-water filtration, air permeability, tensile strength, and porosity tests. The results showed that porosity of prepared hydrogel membranes decreased with increasing alginate concentration from 0.5 % to 1.5 % which resulted in decreased water permeation flux from 2655 h−1/m2 to 475 h−1/m2. The prepared membrane has separation efficiencies for the oil-water mixture in the range of 97.5 % to 99.5 %. Moreover, the developed samples also showed significant antibacterial activity as well as improved mechanical properties. The strength of the prepared membrane is in the range of 40 N to 80 N. The developed sodium alginate hydrogel-based non-woven membrane could have potential applications for commercial water filtration systems.

Effect Of UV-Assisted Titanium Dioxide (TiO2) Photocatalysis on Viable Airborne Bacteria and Fungi in The Seasoning Powder Industry

Titanium dioxide (TiO2) has been known to have anti-microbial activity against fungi, bacteria, and viruses. The application of TiO2 in the membrane attached to the air conditioner was expected to minimize airborne microorganisms. This study contribution to investigate the efficacy of UV-assisted TiO2 photocatalysis in controlling airborne microorganisms in the seasoning powder industry. TiO2 was coated to the non-woven membrane and attached with a UV lamp inside the air conditioner. When the AC was on, the Ti3+ was released into the air. Enumeration of airborne microorganisms was conducted by opening the agar plates for 15 min at several food processing facilities, followed by incubating agar plates for 72 hours at 30 °C. The result shows dry processing facility had the highest number of initial airborne bacteria while the wet production facility had the highest number of initial airborne fungi. Interestingly, the number of airborne microorganisms fluctuated in the packaging facility related to the number of people going inside and outside. On the contrary, the number of airborne microorganisms was deficient in empty rooms, which indicated that the number of airborne microorganisms might be related to people and products. Overall, airborne microorganisms were reduced after 60 min of irradiation. Therefore, it is recommended to irradiate the facilities for 60 min before production start. SEM images and EDAX analysis results show TiO2 was detected after 160 h. However, it was recommended to change the TiO2 membrane after one month. This research was expected to contribute to controlling airborne microorganisms during food production in food processing facilities.

Facile synthesis of TiO2-PAN photocatalytic membrane with excellent photocatalytic performance for uranium extraction from seawater

Uranium, as an important nuclide, has attracted extensive attention because of its high energy density, clean and pollution-free characteristics. Herein, a TiO2-polyacrylonitrile photocatalytic membrane (TPM) was prepared by phase conversion method for efficient uranium extraction. TPM photocatalytic membrane is composed of TiO2, PAN and conductive carbon cloth, in which TiO2 is the main active substance in the photoreduction process and PAN is the membrane-forming substrate material. Carbon cloth can improve the conductivity of the polymer substrate and improve the photocatalytic efficiency to a certain extent ((The uranium extraction reaction rate of the carbon cloth-based TPM membrane was 1.35 and 1.41 times higher than that of the non-substrate and non-woven fabric-based membranes, respectively). TPM photocatalytic membrane has excellent photoreduction performance of hexavalent uranium. Under the optimal reaction conditions (C0 = 100 mg/g, pH = 5), the capacity of uranium extracted is 263.92 mg/g. In addition, TPM photocatalytic membrane also exhibited good reusability (uranium extraction capacity after the fifth cycle is 246.13 mg/g) and selective uranium extraction ability (KdU/KdV = 41.78, and the removal rate of uranium is 74.63 %). The extraction mechanism of uranium can be summarized as the reduction of hexavalent uranium by photogenerated electrons excited in photocatalytic membrane under light condition. In general, this work provides a new strategy for designing simple, low-cost and efficient photocatalytic materials for uranium extraction from seawater.

Syringeless electrospun non-woven separator membrane for high-energy and high-power Li-ion battery application

Developing separators to meet the various requirements of next-generation Li-ion batteries (LIBs) is quite challenging because safety issues (good mechanical and thermal properties) and high power and energy density (small thickness and large porosity) exhibit a negative correlation, resulting in a technical contradiction. In general, an electrospun nonwoven membrane is a potential candidate for use in next-generation LIBs, but sufficiently thin electrospun-based nonwoven webs cannot be used as separators owing to their poor mechanical properties and exceedingly large porosity, which fail to prevent dendrite growth. To overcome these shortcomings, we fabricated a composite nonwoven separator using polyvinylidene fluoride (PVDF) and lithium lanthanum zirconium oxide (Li6.4La3Zr2Al0.2O12, LLZO) particles via a syringeless colloidal electrospinning method. To demonstrate the feasibility of our separator membrane for use in high-power and high-energy LIBs, we evaluated the electrochemical performance of an assembled LiNi0.6Co0.2Mn0.2O2 (NCM622)/graphite cell at a high C-rate. The assembled cell containing our separator membrane delivered an outstanding capacity of 115 mAh∙g-1 with a capacity retention of 97% after 100 cycles, even at 3 C. In addition, a Li-metal cell with our PVDF/LLZO separator achieved capacity retention of 86% after 250 cycles at 0.5 C.