Electrospinning Method Research Articles

On the Hydrogen Peroxide Sensing employing Fibres composed of Polyvinyl alcohol (PVA) and Polyaniline (PANI)

The sensitivity of an electrocatalyst depends upon the kinetics of electrochemical reactions occurring at its surface. In this work, we prepared the polyvinyl alcohol (PVA) and polyaniline (PANI) nanofibres using a facile and cost-effective electrospinning method. We observed that the fibres composed of PANI and PVA exhibited efficient sensing of hydrogen peroxide (H2O2) as compared to the fibres prepared employing PVA alone. At low concentration of H2O2, a two-fold enhancement in the sensing activity is noticed in case of the fibre prepared using PVA-PANI (as compared to PVA fibres). On the other hand, at higher concentration, the sensitivity is around five times high. The enhancement in the sensing activity for PVA-PANI nanofibres is due to the increase in conductivity and electrochemical surface area upon addition of conducting PANI. The increased conductivity enhances the surface energy of the fibre and increased electrochemical surface area enhances the number of reactive sites, which results in enhanced sensing activity. The above analysis is further supported via the impedance analysis showing lower charge transfer resistance for PVA-PANI sample.

Tin-antimony/carbon composite porous fibers: electrospinning synthesis and application in sodium-ion batteries

In this work, tin-antimony/carbon composites porous fibers were successfully synthesized by an electrospinning method combined with two-step heat treatment processes, in which SnCl2 and SbCl3 were used as tin and antimony sources, and polyacrylonitrile (PAN) and polymethyl methacrylate (PMMA) were used as binders and pore-forming agents. The as-synthesized tin-antimony/carbon composites were systematically characterized by x-ray Diffraction (XRD), Transmission Electron Microscope (TEM), Scanning Electron Microscope (SEM), Energy-Dispersive Spectrometer (EDS), x-ray Photoelectron Spectroscopy (XPS), and Thermogravimetric Analysis-Differential Scanning Calorimetry (TG-DSC). The results indicate that the composite material consists of one-dimensional nitrogen-doped carbon porous fibers as the main matrix, with a three-dimensional network structure in which Sn, SnO2, and SnSb particles are encapsulated. Furthermore, the tin-antimony/carbon composites porous fibers were utilized as self-supported negative electrode for sodium-ion batteries. The results showed that the SNbM-2 sample electrode calcined at 800 °C demonstrated the best cycling stability and rate capability among all the sample electrodes, with a discharge capacity of 319.5 mAh·g−1 maintained after 100 cycles at a current density of 0.1 A·g−1. The excellent electrochemical performance of the SNbM-2 sample electrode is benefited from its unique porous structure and the carbon fiber network structure encapsulating Sn, SnO2, and SnSb particles, which could effectively shorten the Na+ ion transport distance and mitigate electrode volume expansion.

The Production of Hollow Nanofibers from PBS / TPU Blends by Coaxial Electrospinning Method

In this study, the production of hollow Polybutylene Succinate (PBS)/Thermoplastic Polyurethane (TPU) nanofibers as biodegradable nanomaterials with improved mechanical properties were carried out by coaxial electrospinning method. The polymer solutions of pure PBS, pure TPU, and PBS/TPU blends (60/40, 40/60, 20/80 w/w) (as the shell) versus pure Polyvinylpyrrolidone (PVP) (as core) were put together for bi-component nanofibers production. The core structure of nanofibers was dissolved in distilled water. Thus, hollow nanofibers were obtained with the removal of PVP from the structure. Characterization studies (SEM, FTIR, and Tensile tests) of hollow nanofibers were performed. The morphological properties of PBS/TPU blends in ratios of 60/40 and 20/80 were observed as homogeneous and non-adhered fiber structures. It was determined that the hollow PBS/TPU (60/40) mat has the thinnest nanofibers. New bond formations within the interactions of substances as studied in the chemistry of blended electrospun webs were examined with FTIR analysis. Therewithal, this test showed the removal of PVP in the core of all nanofibers. It was observed that the adhered fibers increased the tensile stress and decreased the tensile strain at mechanical test results that were verified also by SEM views. It is suggested that the hollow nanofibers produced by this study can be used in the biomedical field as a biodegradable and breathable wound dressing.

Nonsolvent-induced electrospun fibers with crater-like surface and high-loading polytriphenylamine-derived as a flexible cathode for lithium-ion batteries

Fabricating electrodes simultaneously possessing remarkable flexibility, excellent mechanical properties, and high energy density remains a significant challenge in flexible lithium-ion batteries (LIBs). Herein, a series of flexible organic composite films were prepared with high-loading polytriphenylamine (PTPA) and the derivative (PTPA-PO) as active material, along with carbon nanotubes (CNTs) serving as conductive filler. The fabrication employed the polyethylene oxide (PEO) assisted nonsolvent (or poor solvent) induced phase separation electrospinning (NIPSE) method. Subsequently, the fiber morphology and electrochemical applications of the flexible organic composite films were systematically studied. Notably, the 60 % PTPA-PO/20 % CNTs/PEO flexible electrode with a high-loading active material of 60 wt% exhibits a significant discharge capacity of 146.6 mAh·g−1 and a favorable discharge platform ∼ 3.7 V vs. Li. Furthermore, the inherent flexibility of electrode contributes to efficient and stable transport of ions and electrons, resulting in a fine capacity retention of 93.3 % after 100 cycles. The improvement of electrochemical performance can be rationalized by the unique internal conductive network and crater-like surface structure of the fibers formed through the NIPSE method. This work provides an efficient method to fundamentally improve the energy storage performance and flexibility of LIBs.

SnS2 nanosheets/Ag2S quantum dots heterojunction supported by YSZ nanofibers enable real-time room-temperature NO2 gas sensor

Air pollution has emerged as a critical global issue, necessitating the development of effective real-time gas monitoring technologies. However, conventional gas sensors face limitations such as high energy consumption and sluggish response/recovery kinetics. In this study, we report a novel SnS2/Ag2S heterojunction supported by yttria-stabilized zirconia nanofibers (YSZ@SnS2/Ag2S) through a facile electrospinning, hydrothermal and subsequent cation-exchange method. This hierarchical composite nanofiber consists of well-distributed Ag2S quantum dots (QDs) attached to vertical anchored SnS2 nanosheets, forming an interconnected network supported by YSZ nanofibers. The integrated sensor exhibited high response of 3.27 and swift response/recovery times of 12/27 s to 1 ppm NO2 at room temperature, respectively. Benefited from highly permeable three-dimensional continuous conductive nanofibers, along with the hierarchical nanosheets/QDs structure, the gas transmission/diffusion and number of reactive sites were ensured. Additionally, the interfacial built-in electric field of SnS2/Ag2S heterojunction further enhanced the electron transfer, carrier migration and gas-sensitive reaction kinetics. This study provides insights into the development of functional composite nanofibers and paves the way for the exploitation of real-time room-temperature gas sensing applications.

Photosynthetic nano fibers: Living microalgae packaging into polyvinyl alcohol nanofibers using an electrospinning method

AbstractAlthough microalgae are often studied for their biochemical extracts, utilizing them in a viable state opens new avenues for sustainable oxygenation in various systems. This study addresses the challenges of maintaining system homeostasis and presents an effective method for immobilizing live microalgae within poly(vinyl alcohol) (PVA) nanofibers using electrospinning technology. Characterization techniques, including scanning electron microscopy (SEM), fluorescence microscopy, Fourier‐transform infrared (FTIR) spectroscopy, and differential scanning calorimetry (DSC), were used to validate successful immobilization. Rheological studies were performed to investigate the influence of microalgae on the fiber morphology. Changing the PVA concentration, the fiber diameter could be regulated between 150 and 650 nm in the spinnable range. The addition of microalgae to the solution increased the viscosity of the prepared solution and reduced the resulting fiber diameter by approximately 2/3. Our results show that PVA nanofibers effectively encapsulate living microalgae and allow for sustained transport of nutrients and metabolites. The photosynthetic efficacy of the encapsulated microalgae was evaluated using dissolved oxygen measurements and showed two times higher rates of oxygen production and consumption compared with a film‐based approach. Our results show that PVA nanofibers effectively encapsulated living microalgae and allowed for the sustained transport of nutrients and metabolites. This innovative methodology provides a robust platform for immobilizing living microorganisms, with broad implications for applications ranging from regenerative medicine to sustainable agriculture.

Zero-Strain Sodium Lanthanum Titanate Perovskite Embedded in Flexible Carbon Fibers as a Long-Span Anode for Lithium-Ion Batteries.

"High-capacity" graphite and "zero-strain" spinel Li4Ti5O12 (LTO) occupy the majority market of anode materials for Li+ storage in commercial applications. Nevertheless, their intrinsic drawbacks including the unsafe potential of graphite and unsatisfactory capacity of LTO limit the further development of lithium-ion batteries (LIBs), which is unable to satisfy the ever-increasing demands. Here, a novel Na0.35La0.55TiO3 perovskite embedded in multichannel carbon fibers (NLTO-NF) is rationally designed and synthesized through an electrospinning method. It not only has the advantages of a respectable specific capacity of 265 mAh g-1 at 0.1 A g-1 and superb rate capability, but it also possesses the zero-strain characteristic. Impressively, an ultralong cycling life with 96.3% capacity retention after 9000 cycles at 2 A g-1 is achieved in the half cell, and 90.3% of capacity retention ratio is obtained after even 2500 cycles at 1 A g-1 in the coupled LiFePO4/NLTO-NF full cell. This study introduces a new member with excellent performance to the zero-strain materials family for next-generation LIBs.

Chrysin loaded polycaprolactone-chitosan electrospun nanofibers as potential antimicrobial wound dressing

In this study, various concentrations of chrysin (chry) were loaded into polycaprolactone-chitosan (PCL-CTS) nanofibers to develop a potential wound dressing materials using electrospinning method. The structural composition and the morphology of the produced PCL-CTS5, PCL-CTS10 and PCL-CTS15 were analyzed by FE-SEM and FTIR, respectively. By increasing the amount of chry, the average diameter of the nanofibres was also increased to 191 ± 65 nm, 203 ± 72 nm, and 313 ± 69 nm for PCL-CTS5, PCL-CTS10, and PCL-CTS15, respectively. Moreover, the physicochemical characteristics and biological properties of synthesized nanofibers such as tensile testing, in-vitro drug release, porosity, decomposition rate, water absorption rate, water vapor permeability rate, cell viability, antioxidant and antibacterial activity were evaluated. By using Korsmeyer-Peppas and Higuchi kinetic models, the chry release mechanism in all nanofibers was studied in PBS solution, which suggested a Fick's diffusion. In-vitro antioxidant experiments by DPPH assay indicated 24, 43, 61 and 78 % free radical scavenging activity for PCL-CTS, PCL-CTS5, PCL-CTS10 and PCL-CTS15. In-vitro antibacterial examination showed that chry-loaded nanofibers had high antibacterial activity in which were comparable with the standard reagents. In-vitro cytotoxicity results obtained by MTT assay indicated a desired cytocompatibility towards fibroblast cells.

Catalytic CO Oxidation on the Cu+-Ov-Ce3+ Interface Constructed by an Electrospinning Method for Enhanced CO Adsorption at Low Temperature.

It is crucial to eliminate CO emissions using non-noble catalysts. Cu-based catalysts have been widely applied in CO oxidation, but their activity and stability at low temperatures are still challenging. This study reports the preparation and application of an efficient copper-doped ceria electrospun fiber catalyst prepared by a facile electrospinning method. The obtained 10Cu-Ce fiber catalyst achieved complete CO oxidation at a temperature as low as 90 °C. However, a reference 10Cu/Ce catalyst prepared by the impregnation method needed 110 °C to achieve complete CO oxidation under identical reaction conditions. Asymmetric oxygen vacancies (ASOV) at the interface between copper and cerium were constructed, to effectively absorb gas molecules involved in the reaction, leading to the enhanced oxidation of CO. The exceptional ability of the 10Cu-Ce catalyst to adsorb CO is attributed to its unique structure and surface interaction phase Cu+-Ov-Ce3+, as demonstrated by a series of characterizations and DFT calculations. This novel approach of using electrospinning offers a promising technique for developing low-temperature and non-noble metal-based catalysts.

A Novel BST@TPU Membrane with Superior UV Durability for Highly Efficient Daytime Radiative Cooling

AbstractPassive radiative cooling technologies play an integral role in advancing sustainable development. While the potential of polymer‐based radiative cooling materials is increasingly recognized, they often degrade under prolonged ultraviolet (UV) radiation exposure, which undermines both their mechanical and radiative cooling performance. To address this challenge, a coaxial electrospinning method to prepare a BST@TPU membrane, with a core layer of strontium barium titanate nanorods (BST NRs) and a shell layer of thermoplastic polyurethane (TPU) is employed. Capitalizing on the UV absorption and free radical adsorption properties of BST NRs, the UV stability of the TPU membrane is significantly increased. Additionally, the inclusion of high refractive index BST NRs compensates for the decrease in reflectivity caused by their UV absorption. After 216 h of continuous 0.7 kW m−2 UV irradiation, the BST@TPU membrane, which initially exhibits a reflectance of 97.2%, demonstrated a modest decline to 92.1%. Its net radiative cooling power maintains 85.78 W m−2 from the initial of 125.21 W m−2, extending the useful lifetime of the TPU membrane threefold. This innovation extends promise for enhancing the efficiency and durability of radiative cooling materials, contributing to sustainable cooling solutions across various applications.

Achieving a Quasi‐Solid‐State Conversion of Polysulfides via Building High Efficiency Heterostructure for Room Temperature Na–S Batteries

AbstractThe practical application of room temperature sodium–sulfur (RT Na–S) batteries are prevented by the sulfur insulation, the severe shuttling effect of high‐order sodium polysulfides (Na2Sn, 4 ≤ n ≤ 8), and the sluggish reaction kinetics. Therefore, designing an ideal host material to suppress the polysulfides shuttle process and accelerate the redox reactions of soluble NaPSs to Na2S2/Na2S is of paramount importance for RT Na–S batteries. Here, a quasi‐solid‐state transformation of NaPSs is realized by building high efficiency MoC‐W2C heterostructure in freestanding multichannel carbon nanofibers via electrospinning and calcination methods (MoC‐W2C‐MCNFs). The multichannel carbon nanofibers are interlinked micro‐mesoporous structures that can accommodate volume change of electrode materials and confine the entire redox process of NaPSs (restraining the polysulfides shuttle process). Meanwhile, the MoC‐W2C heterostructure with abundant heterointerfaces can facilitate electron/ion transport and accelerate conversion of NaPSs. Consequently, the S/MoC‐W2C‐MCNFs cathode delivers a high capacity of 640 mAh g−1 after 500 cycles at 0.2 A g−1 and an excellent reversible performance of 200 mAh g−1 after ultralong 3500 cycles at 4 A g−1. What's more, the heterostructure catalytic mechanism (a quasi‐solid‐state transformation) is proposed and confirmed in carbonate electrolyte by combining experimentally and theoretically.

Ultrasensitive and Exclusive Chemiresistors with a ZIF-67-Derived Oxide Cage/Nanofiber Co3O4/In2O3 Heterostructure for Acetone Detection.

Gas sensors for acetone detection have received considerable attention because acetone has a significant influence on both the environment and human health, e.g., it is flammable and toxic and may be related to blood glucose levels. However, achieving high sensitivity and selectivity at low concentrations is still a great challenge to date. Here, we report a unique chemiresistive gas sensor for acetone detection, which is composed of In2O3 nanofibers loaded with a porous Co-based zeolitic imidazolate framework (ZIF-67)-derived Co3O4 cage prepared by simple electrospinning and solvothermal methods. The ZIF-67-derived oxide cage/nanofiber Co3O4/In2O3 heterostructure has abundant reversible active adsorption/reaction sites and a type-I heterojunction, resulting in an ultrasensitive response of 954-50 ppm acetone at 300 °C. In addition, it demonstrates a low detection limit of 18.8 ppb, a fast response time of 4 s, good selectivity and repeatability, acceptable humidity interference, and long-term stability. With such excellent sensing performance to acetone, our chemiresistive gas sensor could be potentially applied for environmental monitoring and early diagnosis of diabetes.

Manufacturing 3D Biomimetic Tissue: A Strategy Involving the Integration of Electrospun Nanofibers with a 3D-Printed Framework for Enhanced Tissue Regeneration.

3D printing and electrospinning are versatile techniques employed to produce 3D structures, such as scaffolds and ultrathin fibers, facilitating the creation of a cellular microenvironment in vitro. These two approaches operate on distinct working principles and utilize different polymeric materials to generate the desired structure. This review provides an extensive overview of these techniques and their potential roles in biomedical applications. Despite their potential role in fabricating complex structures, each technique has its own limitations. Electrospun fibers may have ambiguous geometry, while 3D-printed constructs may exhibit poor resolution with limited mechanical complexity. Consequently, the integration of electrospinning and 3D-printing methods may be explored to maximize the benefits and overcome the individual limitations of these techniques. This review highlights recent advancements in combined techniques for generating structures with controlled porosities on the micro-nano scale, leading to improved mechanical structural integrity. Collectively, these techniques also allow the fabrication of nature-inspired structures, contributing to a paradigm shift in research and technology. Finally, the review concludes by examining the advantages, disadvantages, and future outlooks of existing technologies in addressing challenges and exploring potential opportunities.

A novel optical dual sensor based on a coaxial electrospinning method for simultaneous sensing of oxygen and ammonia

The coaxial electrospinning method is widely used in a wide range of applications, including medical devices and sensing technology. This study proposes a novel optical dual sensor for simultaneous detection of oxygen (O2) and ammonia (NH3) based on coaxial electrospinning method to produce core-shell fiber membrane doped fluorescent dyes. The O2 (core) and NH3 (shell) sensitive dye membranes were successfully fabricated using coaxial electrospinning method by dissolving a polymer matrix, cellulose acetate (CA), with platinum (II) meso-tetrakis (pentafluorophenyl) porphyrin (PtTFPP) and Eosin-Y, respectively. The optical dual sensor was illuminated by an UV LED to monitor the intensity change and wavelength shift in the presence of selected analyte gases. The experimental data show that the sensitivities of optical dual sensor were found to be 6.4 and 3.2 for O2 and NH3, respectively. The response and recovery times of O2 and NH3 sensing probes were measured to be 12 s/29 s and 65 s/66 s, respectively. Also, when exposed to NH3 gas gradually from 0 to 500 ppm, the wavelength shift data of Eosin-Y was started at 569.5 nm, 573.9 nm, 578.4 nm, 579.4 nm, 580.8 nm, and 582.2 nm, respectively. In applications, the proposed optical dual sensor based on coaxial electrospinning method can detect O2 and NH3 gases simultaneously.

Robust design of starch composite nanofibrous films for active food packaging: Towards improved mechanical, antioxidant, and antibacterial properties

Developing efficient and biodegradable packaging films is of paramount significance owing to the scarcity of petroleum based resources. However, their applications in food packaging are limited due to their poor mechanical properties and inadequate biological activities. This study proposes a novel approach to develop the starch composite nanofibrous films (SNFs/TA/Fe3+) consisting of starch, tannic acid, and Fe3+ using the temperature-assisted electrospinning method. The addition of TA resulted in a decrease in the rate of thermal degradation, indicating an improvement in the thermal stability of SNFs. However, the incorporation of TA or TA/Fe3+ showed only a slight impact on the internal structure of SNFs. SNFs/TA/Fe3+ loaded with 0.1 wt% of Fe3+ demonstrated a significantly higher tensile strength compared to SNFs and those loaded with TA alone. The presence of TA enhances the antioxidant activity of SNFs, and the robust SNFs/TA/Fe3+ exhibited comparable antioxidant activity to SNFs/TA. However, the SNFs/TA/Fe3+ showed a reduction in antibacterial activity, possibly due to the high valence state of the metal ions. Overall, these findings highlighted that a simple electrospinning method was used to produce SNFs/TA/Fe3+ resulted in improved mechanical properties and antioxidant activity, offering a new strategy for the development of active food packaging using SNFs.

Soluble molecular switches in electrospun nanofibers

Compounds that exhibit the spin crossover effect are known to show a change of spin states through external stimuli. This reversible switching of spin states is accompanied by a change of the properties of the compound. Complexes, like iron (II)-triazole complexes, that exhibit this behavior at ambient temperature are often discussed for potential applications. In previous studies we synthesized iron (II)-triazole complexes and implemented them into electrospun nanofibers. We used Mössbauer spectroscopy in first studies to prove a successful implementation with maintaining spin crossover properties. Further studies from us showed that it is possible to use different electrospinning methods to either do a implementation or a deposition of the synthesized solid SCO material into or onto the polymer nanofibers. We now used a solvent in which both, the used iron (II)-triazole complex [Fe(atrz)3](2 ns)2 and three different polymers (Polyacrylonitrile, Polymethylmethacrylate and Polyvinylpyrrolidone), are soluble. This shall lead to a higher homogeneous distribution of the complex along the nanofibers. Mössbauer spectroscopy and other measurements are therefore in use to show a successful implementation without any significant changes to the complex.

Co-delivery of VEGF and amoxicillin using LP-coated co-axial electrospun fibres for the potential treatment of diabetic wounds

Diabetic complications present throughout a wide range of body tissues, however one of the most widely recognised complications remains to be chronic diabetic wounds. Current treatment options largely rely on standard wound treatment routines which provide no promotion of wound healing mechanisms at different physiological stages of repair. Recently materials produced using novel additive manufacturing techniques have been receiving attention for applications in wound care and tissue repair. Additive manufacturing techniques have recently been used in the interest of targeted drug delivery and production of novel materials resembling characteristics of native tissues. The potential to exploit these highly tailorable manufacturing techniques for the design of novel wound care remedies is highly desirable.In the present study two additive manufacturing techniques are combined to produce a scaffold for the treatment of diabetic wounds. The combination of microfluidic manufacturing of an antimicrobial liposome (LP) formulation and a coaxial electrospinning method incorporating both antimicrobial and proangiogenic factors allowed dual delivery of therapeutics to target both infection and lack of vascularisation at wound sites. The coaxial fibres comprised of a polyvinyl alcohol (PVA) core containing vascular endothelial growth factor (VEGF) and a poly (l-lactide-co-ε-caprolactone) (PLCL) shell blended with amoxicillin (Amox). Additionally, a liposomal formulation was produced to incorporate Amox and adhered to the surface of fibres loaded with Amox and VEGF. The liposomal loading provided the potential to deliver a much higher, more clinically relevant dose of Amox without detrimentally changing the mechanical properties of the material. The growth factor release was sustained up to 7-days in vitro. The therapeutic effect of the antibiotic loading was analysed using a disk diffusion method with a significant increase in zone diameter following LP adhesion, proving the full scaffold system had improved efficacy against both Gram-positive and Gram-negative strains. Additionally, the dual-loaded scaffolds show enhanced potential for supporting vascular growth in vitro, as demonstrated via a viability assay and tubule formation studies. Results showed a significant increase in the average total number of tubes from 10 in control samples to 77 in samples fully-loaded with Amox and VEGF.

Preparation of Zeolitic Imidazolate Framework and Carbon Nanofiber Composites for Nitrofurazone Detection

Metal–organic frame (MOF) materials may have the advantages of a regular pore structure, large porosity, and large specific surface area, which could provide better catalytic activity, but they have some disadvantages in electrocatalysis. In contrast, carbon nanofibers (CNFs) prepared by electrospinning methods have good conductivity and stability. Therefore, this research aimed to generate MOF/CNFs composite materials to improve the electrochemical properties of MOF materials and apply them to the field of electrochemical sensing. This experiment was based on the preparation of straight unidirectional CNFs by an electrospinning method at 2000 RPM. The original method of preparing zeolitic imidazolate frameworks (ZIF-8) was improved and ZIF-8 was uniformly dispersed on the surface of CNFs to form a ZIF-8/CNF composite with a fiber diameter of about 0.10 to 0.35 µm. The specific surface area of the CNFs was about 42.28 m2/g, while that of the ZIF-8/CNF composite was about 999.82 m2/g. The specific surface area of the ZIF-8/CNF composite was significantly larger than that of CNFs. The GCE/ZIF-8/CNF electrode had an excellent electrochemical reaction, with an oxidation peak at about 216 μA, which proved that the ZIF-8/CNF composite material would have good catalytic activity and excellent electrochemical properties for the detection of nitrofurazone compared to other modified electrodes.

Hierarchically nanofibers embedded with NiMnS nanocrystals as anode for high-performance lithium-ion batteries: Experimental and theoretical studies

Transition metal sulfides (TMSs) have been appraised as promising anode materials for lithium-ion batteries (LIBs), however, the average conductivity and drastic pulverization produced by specific volume variation during discharge–charge cycles limit their practical application. To resolve these critical issues, an in-situ fabrication approach has been utilized to develop binary TMS-embedded carbon nanofibers (CFs) by regulating the loading of metallic (cationic) components. Herein, a series of NiMnS/CFs-n composites was prepared by controlling Ni/Mn feeding ratios (n) via successive electrospinning, carbonization and sulfidation method. The inventive engineering procedure provides excellent durability (∼99 % compared to 2nd cycle) up to 250 cycles at 1 A g−1 and superb rate performance for NiMnS/CFs-2.0 anode. The final discharge capacities of NiMnS/CFs-2.0 are 730, 608, 562, 468, 370, and 306 mA h g−1 at 0.1, 0.3, 0.5, 1, 3, and 5 A g−1, respectively. Theoretical calculations enable us to understand the role of typical Ni/Mn feeding ratio on electronic properties and confirm that the hybrid NiMnS/CFs-2.0 surface provides enhanced material conductivity, improved Li adsorption energies for S-top sites, and fast discharge–charge rate with low diffusion energy barrier. Meanwhile, the full-cell containing NiMnS/CFs-2.0 anode outperforms the commercialized graphite anode with a high specific energy of ∼529 W h kg−1 and stable durability, which also successfully enlightens a light bulb. The present study will provide a scalable and simple method to fabricate the integrated composite of binary TMS/CFs by proper cationic regulation and offer useful guidelines for commercial applications of TMS-based anode.

Dual phase change separator combining cooling and thermal shutdown functions for Li-ion battery with enhanced safety

The rapid growth of electric vehicles raises an unmet need to enhance high-temperature performance and safety of Li-ion battery (LIB). Herein, polyethylene glycol/polyvinylidene fluoride (PEG/PVDF) core @ polybutylene succinate (PBS) shell separator with cooling and thermal shutdown functions was fabricated using a one-step coaxial electrospinning method. The separator exhibited superior electrochemical performance even at room temperature due to good wettability and high porosity. When battery temperature rises as discharging, PEG with 50 °C melting point (m.p.) will melt to store heat temporarily. Thus, the separator with cooling function can effectively enhance ion conductivity to alleviate specific capacity drop and polarization voltage increase. As temperature decreases after battery discharging, the separator will release thermal energy to prepare for the next working cycle. When thermal runaway happens and raises temperate above 100 °C rapidly, the PBS shell will melt at 110 °C without skeleton thermal shrinkage. Separator pores can be blocked by the melted PBS and Li+ ions transfer can be inhibited in time to prevent disastrous consequence. Thus, dual phase change of the separator provides a novel and effective strategy for synergistic performance and safety enhancement of high temperature LIB.