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To buffer the unavoidable volume expansion and structure collapse problems of transitional metal sulfides during lithiation process, herein, nanosized α-MnS homogenously embedded in axial multichannel carbon nanofibers was well designed and directly used as freestanding anodes for lithium-ion batteries (LIBs). The obtained carbon nanofibers were interwoven into a flexible and cross-linked film, which offered a 3D successive conductive networks and guaranteed sufficient contact interface for electrode/electrolyte. The nanosized α-MnS was homogenously embedded into the carbon nanofiber framework and surrounded with a thin protective carbon layer, which effectively maintained the structural integrity for a satisfied cycling performance. The high aspect ratio carbon nanofibers with axial open channels supplied sufficient active sites and formed long-range electronic pathways along the axial carbon wall. Meanwhile, the radial voids provided enormous accommodation space to alleviate volume expansion and shortened diffusion paths for faster ionic transfer. Benefitting from the above unique merits, the freestanding electrodes delivered excellent lithium storage performances and remarkable long-term cycling stability, including a high initial reversible capacity of 772 mAh g−1 and excellent cycling capacity retention of 93.4% after 100 cycles at a current density of 0.5 A g−1. [ABSTRACT FROM AUTHOR]

• The metal sulfide nanoparticles are strongly bridged to fiber skeleton. • The interconnected porous structure offers enough elastic space for volume change. • The protective macro-porous skin prevents the shedding of active nanoparticles. An innovative structure of metal sulfide nanoparticles locked in interconnected porous carbon nanofiber with protective macro-porous skin (M x S y @MPCNF) is successfully prepared by electro-blowing spinning technique and subsequent one-step sulfurization/carbonization process. The obtained film is directly used as freestanding anodes for lithium ion batteries (LIBs), which provides a three-dimensional (3D) crosslinked conductive network and ensures the fast penetration of electrolyte. Meanwhile, the interconnected porous structure of fibers provides enough active sites for Li+ storage and shortens the pathways for Li+ transport. Moreover, the protective skin with macro-porous structure endows a fast access pathway for electrolyte and prevents the active nanoparticles from shedding. Most importantly, the metal sulfide nanoparticles are locked in a carbon cage which immobilized by the interconnected porous structure, and strongly bridged to the fiber skeleton through a carbon coating layer. Such a well-designed structure offers enough space for volume change and makes the metal sulfide nanoparticles difficult to detach from the carbon nanofiber support. Benefiting from the above advantages, the optimized freestanding Fe 7 S 8 @MPCNF -15 anodes deliver a high reversible capacity of 776 mAh g−1 at 0.2 A g−1 after 200 cycles, and exhibits an excellent cycling stability after 500 cycles with 86% capacity retention at a high current density of 1 A g−1. Extraordinarily, the synthetic method is very versatile and can be easily extended to fabricate Co 9 S 8 @MPCNF and Ni 9 S 8 @MPCNF composites with excellent electrochemical performances, which will shed some lights on the development of flexible anodes for various energy conversion and storage systems. [ABSTRACT FROM AUTHOR]

Abstract Al 2 O 3 fibers, especially with unique morphology and structure, are a fascinating class of ceramics that have been widely used as catalyst supports. In this work, smooth, porous and needle-like Al 2 O 3 fibers are successfully prepared by electro-blowing spinning (EBS) method. Effects of calcination temperature, calcination rate and pore forming agent content (Polytetrafluoroethylene, PTFE) on the morphology and structure of Al 2 O 3 fibers are systematically studied. Most importantly, Al 2 O 3 fibers with different morphologies are particular suitable to be used as CuO supports for selective oxidation of 5-hydroxymethyl-2-furfural (HMF) to 2,5-furandicarboxylic acid (FDCA). Benefiting from the unique structure, FDCA synthesis over the needle-like CuO/Al 2 O 3 fibers achieves 98.6% yield, which is much higher than the yields over smooth and porous CuO/Al 2 O 3 fibers. Moreover, the fiber catalysts could be easily recovered and reused without the loss of its activity. It is anticipated that Al 2 O 3 fibers with needle-like mullite will shed some light on the development of profiled ceramic fibers for various applications. [ABSTRACT FROM AUTHOR]

In this paper, flexible mesoporous Si-doped Al 2 O 3 ultrafine fibers were successfully prepared by electro-blow spinning (EBS) technology followed by a calcination process. The effects of spinning parameters, including air pressure, voltage, and solution injection rate on the morphology and diameter of fibers were investigated. The results showed that the spinning parameters played a key role on determining the morphology and diameter of fibers, and the specific surface area of fibers significantly increased with the increasing content of pore forming agents (polytetrafluoroethylene, PTFE), at the same time the pore size distribution was mainly concentrated at ~5 nm. Most importantly, Si(OC 2 H 5 ) 4 was introduced to act as the flexible regulator which could inhibit the growth of alumina crystal, decrease the crystal size, and thus the flexibility of obtained mesoporous Si-doped Al 2 O 3 ultrafine fibers can be improved. Moreover, the fibers productivity by EBS method was higher than that of traditional electro-spinning. In the future, the mesoporous Si-doped Al 2 O 3 ultrafine fibers may perform desired function and spread their applications in different areas. [ABSTRACT FROM AUTHOR]

Porous CeO 2 /CuO/Al 2 O 3 fibers were successfully prepared, for the first time by electro-blown spinning method. The size of fibers diameter and the number of pores on fibers surface could be controlled by adjusting spinning parameters. The composite fibers showed continuous line feature and porous morphologies after heat treatment. To obtain the optimum spinning parameters, the effects of polyvinyl pyrrolidone (PVP) concentrations, air pressures, high voltages, injection rates, polytetrafluoroethylene (PTFE) contents and calcination temperatures were investigated. The morphologies and structures of the CeO 2 /CuO/Al 2 O 3 fibers were investigated by Scanning electron microscopy (SEM), Energy dispersive spectrometer (EDS) and X-ray diffraction (XRD). This novel electro-blown spinning method may realize the industrialized production of high performance ceramics fibers. [ABSTRACT FROM AUTHOR]

A new strategy was developed to fabricate superhydrophobic nylon 6 nanofibers, in which the blend solutions of poly(dimethylsiloxane) (PDMS) prepolymer and nylon 6 was spun using an innovative solution blowing process, and then the PDMS prepolymer contianning nanofibers were cured to obtain PDMS/nylon 6 nanofiber mats. Morphology, surface composition, non-wetting property and protective performance were investigated. The results showed that the addition of PDMS prepolymer improved the spinnability of the spinning solutions, and the PDMS/nylon 6 nanofibers had smooth surfaces and diameters from 100 nm to 350 nm. The presence of PDMS effectively enhanced the hydrophobicity of the nanofiber mats, showing water contact angles of 132° to 161° for PDMS contents of 1 wt% to 3 wt%. The PDMS/nylon 6 mats also possessed excellent protective and transport properties. The results indicated the potential application of the novel nanofiber mats in protective clothing. [ABSTRACT FROM AUTHOR]

[Display omitted] • The ZnF 2 -PCNFs interlayer was successfully prepared. • The PCNFs and ZnF 2 produced an excellent synergistic effect to suppress the Li dendrite growth. • The interlayer provided a high Li ions and electronic transmission channel. • The Li||LFP battery and Li symmetric battery with the interlayer displayed stable long cycle performance. • The interlayer could absorb lithium polysulfides and enhance the cycle stability of Li||S batteries. In this work, the ZnF 2 doped three-dimensional (3D) porous carbon nanofibers (ZnF 2 -PCNFs) were prepared via the electro-blow spinning (EBS) and carbonization strategy. And its applications as promising interlayer to hybridize with metal Li as composite anode for lithium metal batteries (LMBs) were systematically investigated and researched. The 3D interconnected porous skeleton with a high electrical conductivity and large surface area could reduce the local current density and endow the significantly enhanced interfacial compatibility between the interlayer and lithium electrode including a high lithium-loading capacity. Moreover, the lithiophilic ZnF 2 nanoparticles formed in-situ during carbonization process could provide more active sites to trigger an analogous alloying reaction with Li to guide the Li plating/stripping more homogeneous. For the assembled Li||LiFePO 4 (LFP) batteries with ZnF 2 -PCNFs, the optimal initial discharge capacity and capacity retention after 500 cycles at 1C were 142.70 mAh g−1 and 96.42%, respectively. The symmetric Li||Li batteries further showed that the ZnF 2 -PCNFs coating interlayer could hinder Li dendrite growth and improve the cycling stability. In addition, the obtained Li||S battery with ZnF 2 -PCNFs also delivered the outstanding cycle performance among the various samples based on the convenient transport channels of Li ions and the strong adsorption or captured ability of ZnF 2 -PCNFs to species. These facts demonstrated that the prepared ZnF 2 -PCNFs coating acting as interlayer between separator and anode could effectively enhance safety and electrochemical performance of LMBs. [ABSTRACT FROM AUTHOR]

A novel method for fabricating highly ordered porous anodic alumina (PAA) with continuously tunable interpore distance using phosphoric/oxalic acid mixed electrolyte was presented. PAA films with different pore diameters and interpore distances were fabricated by changing anodizing potential and concentration of oxalic acid, characterized by field emission scanning electron microscope (FESEM). Experimental results showed oxalic acid in mixed electrolyte could not only suppress the breakdown of PAA at high potential but also enlarge the continuously tunable interpore distance from 300 to 500 nm. The proportionality constant between interpore distance and anodizing potential is 2.48 at the potential from 180 to 200 V, 2.31 at the potential from 130 to 170 V. The optimal content of oxalic acid and potential has a second power function relationship. Our results could extend the applications of PAA templates in ordered nano-material fabrication field. [ABSTRACT FROM AUTHOR]

The bionic design of MnO 2 @PVDF/TBAC LVNM as gel polymer electrolyte matrix for LIC with excellent cycle performance and thermal stability. • A leaf-vein-like nanofiber gel polymer Electrolyte membrane coated MnO 2 nanosheets was fabricated. • The membrane possessed good mechanical property and excellent electrolyte uptake. • The membrane exhibited outstanding cycle stability and excellent thermal stability. Many anode materials are fabricated and their behaviors in Li-ion capacitors (LIC) are investigated to reduce the imbalance of the power capability between the electrodes, which greatly affects the cycle performance of LIC. Yet, the separator of LIC was left out of this contribution. In this work, the in-situ growth of manganese dioxide@polyvinylidene fluoride/tetrabutylammonium chloride (MnO 2 @PVDF/TBAC) leaf-vein-like nanofiber membrane (LVNM) with enhanced mechanical properties and excellent porosity was developed to effectively improve the ionic conductivity of the matrix and to improve the cycle performance of the LIC. Multi-walled carbon nanotubes (MWCNTs) was employed as reducing agent to produce in-situ growth of MnO 2 nanosheets as the shell of the nanofibers, which not only further enhanced the LIC cyclability by providing additional capacity for LIC, but also avoided short circuit problem. The leaf-vein-like structure could greatly enhance the porosity and electrolyte retention of the matrix to accelerate ion transport between the two electrodes. Meanwhile, the in-situ growth of MnO 2 nanosheets could promote the thermal stability of the gel polymer electrolyte (GPE) matrix and improve the LIC cycle stability. The MnO 2 @PVDF/TBAC matrix possessed excellent thermal stability (rose to 170 °C), high porosity (73%) and good ionic conductivity (2.95 * 10−3 S/cm). The LIC assembled with MnO 2 @PVDF/TBAC LVNM showed enhanced specific capacitance (19.5 F g−1), good rate capability, superior cycling stability (67.20% capacity retention after 10,000 cycles at 0.5 C), and high coulombic efficiency (~100%). Thus, our work provides an effective strategy for enhancing the thermal stability and cyclability of LIC. [ABSTRACT FROM AUTHOR]