A Comparatively Low Cost, Easy-To-Fabricate, and Environmentally Friendly PVDF/Garnet Composite Solid Electrolyte for Use in Lithium Metal Cells Paired with Lithium Iron Phosphate and Silicon.

Solid electrolytes may be the answer to overcome many obstacles in developing the next generation of renewable batteries. A novel composite solid electrolyte (CSE) composed of a poly(vinylidene fluoride) (PVDF) base with an active nanofiber filler of aluminum-doped garnet Li ceramic, Li salt lithium bis-(trifluoromethanesulfonyl)imide (LiTFSI), Li fluoride (LiF) stabilizing additive, and plasticizer sulfolane was fabricated. In a Li|CSE|LFP cell with this CSE, a high capacity of 168 mAh g-1 with a retention of 98% after 200 cycles was obtained, representing the best performance to date of a solid electrolyte with a PVDF base and a garnet inorganic filler. In a Li metal cell with Si and Li, it yielded a discharge capacity of 2867 mAh g-1 and was cycled 60 times at a current density of 100 mAh g-1, a significant step forward in utilizing a solid electrolyte of any kind with the desirable Si anode. In producing this CSE, the components and fabrication process were chosen to have a lower cost and improved safety and environmental impact compared with the current state-of-the-art Li-ion battery.

Flexible Centrifugally Spun N, S-Doped SnS2-Including Porous Carbon Nanofiber Electrodes for Na-Ion Batteries.

Carbon nanofibers are promising for various applications such as energy storage, sensors, and biomedical applications; however, the brittle structure of nanofibers limits the usage of carbon nanofibers. For the first time, a facile and effective strategy is reported to fabricate flexible carbon nanofibers via a fast and safe nanofiber fabrication technique, centrifugal spinning, followed by heat treatment. Moreover, sulfidization was employed to fabricate high-performance flexible N, S-doped SnS2-including porous carbon nanofiber electrodes for sodium ion batteries via centrifugal spinning. Binder-free flexible centrifugally spun N, S-doped SnS2-including porous carbon nanofiber electrodes delivered a high reversible capacity of over 460 mAh/g at 100 mA/g. Furthermore, at a high current density of 1 A/g, the electrodes showed a reversible capacity of over 300 mAh/g with excellent cycling stability in 2000 cycles. This work reports a fast, low-cost, and facile way to prepare flexible carbon nanofibers with tunable morphology and various compositions, which could be applicable for different energy storage applications.

Innovative tarantula hair-inspired washing machine filters for enhanced microfiber capture.

Aquatic environments are being polluted by microplastics primarily originating from the washing of synthetic textiles. Microfibers (MF), which are microplastics in synthetic fibers, are consistently introduced into the environment with each domestic laundry cycle. To address this issue, we developed a specialized MF capture "barbed filter" (BF) by transforming PET monofilaments of different diameters (0.4, 0.6, and 0.8 mm) into structures that closely resemble the characteristics of tarantula urticating hairs. BFs feature sharp barbs that effectively capture and retain microfibers of diverse lengths, surpassing the performance of conventional control filters. The BFs had a retention efficiency of 88-91 %, while the CFs had an efficiency of 79-86 %. Our findings revealed that the barbed filter significantly outperformed the conventional control filter in capturing microfibers due to its smaller pore size, shorter pore distance, and unique filter shape. This design not only enhances the surface area and friction, facilitating microfibril strong entrapment but also minimizes the probability of microfibril passage through the filter. This research offers a promising solution for reducing microfibril release from laundry and textile industrial wastewater. The implementation of BFs in real life has the potential to significantly reduce microplastic pollution and promote a cleaner and more sustainable environment.

Special Issue "Fabrication and Characterization of Nanostructured Carbon Electrodes".

The nanostructured carbon materials are promising electrode materials and have been widely studied owing to their tailorable structures, which offer large active sites and reduce the path of transport for mass and charge and thus provide fast pathways for electrons in rechargeable batteries and supercapacitors [...].

Centrifugally Spun Binder-Free N, S-Doped Ge@PCNF Anodes for Li-Ion and Na-Ion Batteries.

Germanium has a high theoretical capacity as an anode material for sodium-ion batteries. However, germanium suffers from large capacity losses during cycling because of the large volume change and loss of electronic conductivity. A facile way to prepare germanium anodes is critically needed for next-generation electrode materials. Herein, centrifugally spun binder-free N, S-doped germanium@ porous carbon nanofiber (N, S-doped Ge@ PCNFs) anodes first were synthesized using a fast, safe, and scalable centrifugal spinning followed by heat treatment and N, S doping. The morphology and structure of the resultant N, S-doped Ge@ PCNFs were investigated by scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray mapping, Raman spectroscopy, and X-ray diffraction, while electrochemical performance of N, S-doped Ge@ PCNFs was studied using galvanostatic charge-discharge tests. The results demonstrate that a nanostructured Ge homogeneously distributed on tubular structured porous carbon nanofibers. Moreover, N, S doping via thiourea treatment is beneficial for lithium- and sodium-ion kinetics. While interconnected PCNFs buffered volume change and provided fast diffusion channels for Li ions and Na ions, N, S-doped PCNFs further improved electronic conductivity and thus led to higher reversible capacity with better cycling performance. When investigated as an anode for lithium-ion and sodium-ion batteries, high reversible capacities of 636 and 443 mAhg-1, respectively, were obtained in 200 cycles with good cycling stability. Centrifugally spun binder-free N, S-doped Ge@ PCNFs delivered a capacity of 300 mAhg-1 at a high current density of 1 A g-1, indicating their great potential as an anode material for high-performance sodium-ion batteries.

N-Doped carbon nanoparticles on highly porous carbon nanofiber electrodes for sodium ion batteries.

Nitrogen doped carbon nanoparticles on highly porous carbon nanofiber electrodes were successfully synthesized via combining centrifugal spinning, chemical polymerization of pyrrole and a two-step heat treatment. Nanoparticle-on-nanofiber morphology with highly porous carbon nanotube like channels were observed from SEM and TEM images. Nitrogen doped carbon nanoparticles on highly porous carbon nanofiber (N-PCNF) electrodes exhibited excellent cycling and C-rate performance with a high reversible capacity of around 280 mA h g-1 in sodium ion batteries. Moreover, at 1000 mA g-1, a high reversible capacity of 172 mA h g-1 was observed after 300 cycles. The superior electrochemical properties were attributed to a highly porous structure with enlarged d-spacings, enriched defects and active sites due to nitrogen doping. The electrochemical results prove that N-PCNF electrodes are promising electrode materials for high performance sodium ion batteries.

Centrifugally Spun PVA/PVP Based B, N, F Doped Carbon Nanofiber Electrodes for Sodium Ion Batteries.

Owing to their high electrical conductivity, high surface area, low density, high thermal stability, and chemical stability, carbon nanofibers have been used in many fields, including energy storage, electromagnetic shielding, filtering, composites, sensors, and tissue engineering. Considering the environmental impact of petroleum-based polymers, it is vital to fabricate carbon nanofibers from environmentally-friendly materials using fast and safe techniques. PVA/PVP nanofibers were fabricated via centrifugal spinning and the effects of variations in the PVP content on the morphology and thermal properties of PVA/PVP-blend nanofibers were studied using SEM and DSC analyses. Moreover, the effects of carbonization conditions, including stabilization time, stabilization temperature, carbonization time, and carbonization temperature on the morphology and carbon yield, were investigated. Centrifugally spun PVA/PVP-based carbon nanofiber electrodes with an average fiber diameter around 300 nm are reported here for the first time. Furthermore, centrifugally spun PVA/PVP-based B, N, F-doped carbon nanofibers were fabricated by combining centrifugal spinning and heat treatment. Through B, N, F doping, CNFs demonstrated a high reversible capacity of more than 150 mAh/g in 200 cycles with stable cycling performance.

MoS2-Decorated Graphene@porous Carbon Nanofiber Anodes via Centrifugal Spinning.

Sodium-ion batteries (SIBs) are promising alternatives to lithium-ion batteries as green energy storage devices because of their similar working principles and the abundance of low-cost sodium resources. Nanostructured carbon materials are attracting great interest as high-performance anodes for SIBs. Herein, a simple and fast technique to prepare carbon nanofibers (CNFs) is presented, and the effects of carbonization conditions on the morphology and electrochemical properties of CNF anodes in Li- and Na-ion batteries are investigated. Porous CNFs containing graphene were fabricated via centrifugal spinning, and MoS2 were decorated on graphene-included porous CNFs via hydrothermal synthesis. The effect of MoS2 on the morphology and the electrode performance was examined in detail. The results showed that the combination of centrifugal spinning, hydrothermal synthesis, and heat treatment is an efficient way to fabricate high-performance electrodes for rechargeable batteries. Furthermore, CNFs fabricated at a carbonization temperature of 800 °C delivered the highest capacity, and the addition of MoS2 improved the reversible capacity up to 860 mAh/g and 455 mAh/g for Li- and Na-ion batteries, respectively. A specific capacity of over 380 mAh/g was observed even at a high current density of 1 A/g. Centrifugal spinning and hydrothermal synthesis allowed for the fabrication of high-performance electrodes for sodium ion batteries.

Exploring the Diverse Morphology of Porous Poly(Lactic Acid) Fibers for Developing Long-Term Controlled Antibiotic Delivery Systems.

In this study, we aimed to explore the morphologies of porous poly(lactic acid) (PLA) fibers through liquid−liquid phase separation, and investigate the relationship among pore formation, physical properties, and antibacterial activities of the fibers for identifying their potential as drug delivery carriers. Antibacterial activities of gentamicin-, kanamycin-, and amikacin-loaded PLA fibers against E. coli and S. epidermidis were evaluated. The antibacterial activity of drugs against E. coli showed the following profile: gentamicin > amikacin > kanamycin; however, S. epidermidis growth was almost completely inhibited immediately after the administration of all three drugs. The efficiency of gentamicin can be attributed to the electrostatic interactions between the positively and negatively charged antibiotic and bacterial cell membrane, respectively. Furthermore, gentamicin-loaded porous PLA fibers were evaluated as drug delivery systems. The cumulative amount of gentamicin in porous PLA nanofibers was considerably higher than that in other PLA fibers for 168 h, followed by 7:3 PLA > 6:4 PLA > 5:5 PLA > non-porous PLA. The 7:3 PLA fibers were projected to be ideal drug carrier candidates for controlled antibiotic release in delivery systems owing to their interconnected internal structure and the largest surface area (55.61 m2 g−1), pore size (42.19 nm), and pore volume (12.78 cm3 g−1).

Recent Developments of Tin (II) Sulfide/Carbon Composites for Achieving High-Performance Lithium Ion Batteries: A Critical Review.

The ever-increasing worldwide energy demand and the limited resources of fossil have forced the urgent adoption of renewable energy sources. Additionally, concerns over CO2 emissions and potential increases in fuel prices have boosted technical efforts to make hybrid and electric vehicles more accessible to the public. Rechargeable batteries are undoubtedly a key player in this regard, especially lithium ion batteries (LIBs), which have high power capacity, a fast charge/discharge rate, and good cycle stability, while their further energy density improvement has been severely limited, because of the relatively low theoretical capacity of the graphite anode material which is mostly used. Among various high-capacity anode candidates, tin (II) sulfide (SnS2) has been attracted remarkable attention for high-energy LIBs due to its enormous resource and simplicity of synthesis, in addition to its high theoretical capacity. However, SnS2 has poor intrinsic conductivity, a big volume transition, and a low initial Coulombic efficiency, resulting in a short lifespan. SnS2/carbon composites have been considered to be a most promising approach to addressing the abovementioned issues. Therefore, this review summarizes the current progress in the synthesis of SnS2/carbon anode materials and their Li-ion storage properties, with special attention to the developments in Li-based technology, attributed to its immense current importance and promising prospects. Finally, the existing challenges within this field are presented, and potential opportunities are discussed.

Flexible MoS2 Anchored on Ge-Containing Carbon Nanofibers.

Germanium is a promising anode material for sodium-ion batteries (SIBs) because of its high theoretical specific capacity, high ion diffusivity, and rate capability. However, large volume changes and pulverization deteriorate the cycling performance. In this study, flexible electrospun germanium/carbon nanofibers (Ge/CNFs) were prepared via electrospinning followed by heat treatment. MoS2 nanoparticles were subsequently anchored on the flexible Ge/CNFs via hydrothermal synthesis. Flexible MoS2 anchored on Ge/CNFs (MoS2@Ge/CNFs) was used as a self-standing binder-free anode in an SIB. Because of the high electronic conductivity of CNFs and the many active sites of MoS2 nanoparticles, a high initial capacity of over 880 mAh/g was achieved at a current density of 0.1 A/g. Moreover, the flexible binder-free MoS2@Ge/CNFs exhibited an excellent C-rate performance with a reversible capacity of over 300 mAh/g at a current density of 2 A/g. Therefore, we demonstrated that flexible binder-free MoS2@Ge/CNFs are a promising electrode candidate for a high-performance rechargeable battery.

The Bacterial Control of Poly (Lactic Acid) Nanofibers Loaded with Plant-Derived Monoterpenoids via Emulsion Electrospinning.

Plant-derived monoterpenoids have been shown to possess various biological effects, providing a scientific basis for their potential usage as antibacterial agents. Therefore, considering problems surrounding bacteria's antibacterial resistance, the utilization of natural antimicrobial compounds such as monoterpenoids in different industries has gained much attention. The aim of this study was to fabricate and characterize various concentrations of plant-derived monoterpenoids, geraniol (G) and carvacrol (C), loaded into poly(lactic acid) (PLA) nanofibers via emulsion electrospinning. The antibacterial activities of the fabricated nanofibers were evaluated using three types of antibacterial assays (inhibition zone tests, live/dead bacterial cell assays, and antibacterial kinetic growth assays). Among the samples, 10 wt% carvacrol-loaded PLA nanofibers (C10) had the most bactericidal activity, with the widest inhibition zone of 5.26 cm and the highest visible dead bacteria using the inhibition zone test and live/dead bacterial cell assay. In order to quantitatively analyze the antibacterial activities of 5 wt% carvacrol-loaded PLA nanofibers (C5), C10, 5 wt% geraniol-loaded PLA nanofibers (G5), and 10 wt% geraniol-loaded PLA nanofibers (G10) against E. coli and S.epidermidis, growth kinetic curves were analyzed using OD600. For the results, we found that the antibacterial performance was as follows: C10 > C5 > G10 > G5. Overall, carvacrol or geraniol-loaded PLA nanofibers are promising antibacterial materials for improving fiber functionality.

High-performance nanostructured bio-based carbon electrodes for energy storage applications.

Polyacrylonitrile (PAN)-based carbon precursor is a well-established and researched material for electrodes in energy storage applications due to its good physical properties and excellent electrochemical performance. However, in the fight of preserving the environment and pioneering renewable energy sources, environmentally sustainable carbon precursors with superior electrochemical performance are needed. Therefore, bio-based materials are excellent candidates to replace PAN as a carbon precursor. Depending on the design requirement (e.g. carbon morphology, doping level, specific surface area, pore size and volume, and electrochemical performance), the appropriate selection of carbon precursors can be made from a variety of biomass and biowaste materials. This review provides a summary and discussion on the preparation and characterization of the emerging and recent bio-based carbon precursors that can be used as electrodes in energy storage applications. The review is outlined based on the morphology of nanostructures and the precursor's type. Furthermore, the review discusses and summarizes the excellent electrochemical performance of these recent carbon precursors in storage energy applications. Finally, a summary and outlook are also given. All this together portrays the promising role of bio-based carbon electrodes in energy storage applications.

TiO2-decorated porous carbon nanofiber interlayer for Li-S batteries.

Lithium-sulfur (Li-S) batteries are the most promising energy storage systems owing to their high energy density. However, shuttling of polysulfides detracts the electrochemical performance of Li-S batteries and thus prevents the commercialization of Li-S batteries. Here, TiO2@porous carbon nanofibers (TiO2@PCNFs) are fabricated via combining electrospinning and electrospraying techniques and the resultant TiO2@PCNFs are evaluated for use as an interlayer in Li-S batteries. TiO2 nanoparticles on PCNFs are observed from SEM and TEM images. A high initial discharge capacity of 1510 mA h g-1 is achieved owing to the novel approach of electrospinning the carbon precursor and electrospraying TiO2 nanoparticles simultaneously. In this approach TiO2 nanoparticles capture polysulfides with strong interaction and the PCNFs with high conductivity recycle and re-use the adsorbed polysulfides, thus leading to high reversible capacity and stable cycling performance. A high reversible capacity of 967 mA h g-1 is reached after 200 cycles at 0.2C. The cell with the TiO2@PCNF interlayer also delivers a reversible capacity of around 1100 mA h g-1 at 1C, while the cell without the interlayer exhibits a lower capacity of 400 mA h g-1. Therefore, this work presents a novel approach for designing interlayer materials with exceptional electrochemical performance for high performance Li-S batteries.

Chamber-confined silicon-carbon nanofiber composites for prolonged cycling life of Li-ion batteries.

Silicon is a promising high capacity (4200 mA h g(-1)) anode material for lithium ion batteries but the significant volume change (over 300%) of silicon during lithiation/delithiation remains a challenge in terms of silicon pulverization and solid-electrolyte-interphase (SEI) accumulation in the silicon composite electrode. To alleviate the volumetric change of silicon, we built a flexible and self-supporting carbon-enhanced carbon nanofiber (CNF) structure with vacant chamber to encapsulate Si nanoparticles (vacant Si@CNF@C). This composite was tested directly without any polymer and current collector. The confined vacant chamber allowed the increasing volume of silicon and SEI accumulates to be well retained for a long cycle life. This chamber-confined silicon-carbon nanofiber composite exhibited an improved performance in terms of good cycling performance (620 mA h g(-1)), high coulombic efficiency (99%), and good capacity retention (80%) after 200 cycles. This self-supported silicon-carbon nanofiber structure showed high flexibility and good electrochemical performance for the potential as flexible electrode for lithium-ion batteries.