Advanced Fiber Materials最新文献

Lithium–sulfur (Li–S) batteries can potentially outperform state-of-the-art lithium-ion batteries, but their further development is hindered by challenges, such as poor electrical conductivity of sulfur and lithium sulfide, shuttle phenomena of lithium polysulfides, and uneven distribution of solid reaction products. Herein, free-standing carbon nanofibers embedded with oxygen-deficient titanium dioxide nanoparticles (TiO_2-x/CNFs) has been fabricated by a facile electrospinning method, which can support active electrode materials without the need for conductive carbon and binders. By carefully controlling the calcination temperature, a mixed phase of rutile and anatase was achieved in the TiO_2-x nanoparticles. The hybridization of anatase/rutile TiO_2-x and the oxygen vacancy in TiO_2-x play a crucial role in enhancing the conversion kinetics of lithium polysulfides (LiPSs), mitigating the shuttle effect of LiPSs, and enhancing the overall efficiency of the Li–S battery system. Additionally, the free-standing TiO_2-x/CNFs facilitate uniform deposition of reaction products during cycling, as confirmed by synchrotron X-ray imaging. As a result of these advantageous features, the TiO_2-x/CNFs-based cathode demonstrates an initial specific discharge capacity of 787.4 mAh g⁻¹ at 0.5 C in the Li–S coin cells, and a final specific discharge capacity of 584.0 mAh g⁻¹ after 300 cycles. Furthermore, soft-packaged Li–S pouch cells were constructed using the TiO_2-x/CNFs-based cathode, exhibiting excellent mechanical properties at different bending states. This study presents an innovative approach to developing free-standing sulfur host materials that are well suited for flexible Li–S batteries as well as for various other energy applications.

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The demand for wearable electronics is still growing, and the rapid development of new electrochemical materials and manufacturing processes allows for innovative approaches to power these devices. Here, three-dimensional (3D) self-supported reduced graphene oxide/poly(3,4-ethylenedioxythiophene) (rGO/PEDOT) hybrid fiber fabrics are systematically designed and constructed via phase inversion-based microfluidic-fiber-spinning assembly (MFSA) method, followed by concentrated sulfuric acid treatment and chemical reduction. The rGO/PEDOT fiber fabrics demonstrate favorable flexibility, interconnected hierarchical network, large specific surface area, high charge storage capacity, and high electrical conductivity. In addition, the all-solid-state supercapacitor made of these rGO/PEDOT fiber fabrics proves large specific capacitance (1028.2 mF cm⁻²), ultrahigh energy density (22.7 μWh cm⁻²), long-term cycling stability, and excellent flexibility (capacitance retention remains at 84%, after 5000 cycles of continuous deformation at 180^o bending angles). Further considering those remarkable electrochemical properties, a wearable self-powered device with a sandwich-shaped supercapacitor (SC) is designed to impressively light up LEDs and power mini game console, suggesting its practical applications in flexible and portable smart electronics.

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The green preparation of highly dispersed carbon nanotube (CNT) conductive inks remains a critical challenge in the field of flexible electronics. Herein, a waterborne CNT dispersion approach mediated by carboxylated cellulose nanofibers (C-CNFs) was proposed. CNFs, special biomass materials with excellent nanostructures and abundant active surface groups, are used as green dispersants. During the dispersion process, benefiting from chemical charge and dimensional matching, C-CNF/CNT wicking-driven stable composite structures (CCNTs) were co-assembled via hydrogen bonding, electrostatic stabilization and π–π stacking between the interfaces, generating controlled orientational structures and promoting stable dispersion and conductivity of CNTs, which were demonstrated via molecular dynamics simulations combined with a variety of physicochemical characterization methods. The dispersion concentration of CNTs in a CCNT slurry can reach 80 wt%, and the obtained CCNT slurry has a low zeta potential (less than − 60 mV) and good stability. Due to the film-forming properties of CNFs and in-plane oriented self-assembly of CCNT, the composite self-supporting films were fabricated with high electrical conductivity (67 S cm⁻¹) and mechanical performance (tensile strength of 153 MPa). In addition, the resulting biobased CCNT ink is compatible with a variety of printing processes and adaptable to various substrates. Moreover, this ink can be used to construct multifunctional advanced sensors with electrochemical, electrothermal, and deformation/piezoresistive responses, which demonstrate excellent performance in monitoring human health.

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An advance in the integration of high-performing semiconductors into fibers enables innovative fiber devices and fabric systems that sense, communicate and interact, paving the way for unprecedented applications in wearable technology, fabric computation, and ambient intelligence.

The insufficient comprehensive mechanical properties and inadequate flexibility of wearable sensors limit their body-protection capability, durability, and comfort. There are challenges in using flexible wearable devices for high-performance practical applications, especially on large scales. Here, an ultrahigh-strength ultra-high-molecular-weight polyethylene braided smart yarn (UBSY) has been designed and mass produced. It is based on triboelectric nanogenerators and prepared by combining commercial ultra-high-molecular-weight polyethylene yarn and conductive yarn with a cored biaxial braided structure. Structural parameters, including the ultra-high-molecular-weight polyethylene yarn diameter, twist, and braiding pitch, are optimized to balance the mechanical properties and electrical outputs. The prepared UBSYs are characterized based on a range of reliable properties, including ultrahigh tensile strength (194.83 N), excellent abrasive resistance (up to 306 abrasive cycles), great hydrophobicity (water contact angle of 115.49°), acid and alkali splash resistance, and decent triboelectric outputs (1.5 V, 3.0 nA, and 0.5 nC). An intelligent weft-knitted textile wearable sensor is fabricated with UBSY using a matured flat-knitting technique, which provides excellent mechanical strength, physical protection and comfort. Furthermore, a pair of smart elbow guards have been demonstrated to highlight UBSY-based wearable sensors’ potential in outdoor sports management. In addition, equipped with a satisfactory body protective capacity against various risks and matured preparation technologies, the UBSY-based wearable sensor provides a practical solution for large-scale applications of high-performance motion sensing in complex environments.

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Sulfurized polyacrylonitrile (SPAN) has emerged as an excellent cathode material for lithium–sulfur batteries (LiSBs), and it addresses the shuttle effect through a solid‒solid reaction. However, the actual sulfur loadings in SPAN often remain below 40 wt%. Due to the susceptibility of polysulfides-to-nucleophilic reactions with electrolytes, achieving physical encapsulation of elemental sulfur is a challenging task. In this study, a free-standing cathode material with a high sulfur/selenium (S/Se) loading of 55 wt% was fabricated by introducing SeS_x into the unique lotus root-like pores of porous SeS_xPAN nanofiber membranes by electrospinning and a two-step heat treatment. Insoluble compounds were formed due to nucleophilic interactions between lithium polyselenosulfides (LiSeS_x) and the electrolyte, which potently blocked the existing lotus root-like pores and facilitated the creation of a thin cathode–electrolyte interphase on the fiber surface. This dual functionality of LiSeS_x safeguarded the active material embedded within the porous structure. The SeS₁₅PAN cathode exhibited remarkable cycling stability with almost no degradation after 200 cycles at 0.2 C, along with a high discharge capacity of 580 mAh/g. This approach presents a solution for addressing the insufficient sulfur content in SPAN.

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With the rapid development of 5G communication and artificial intelligence (AI) technology, electromagnetic radiation pollution is emerging as a serious issue. Achieving both uniform dispersion and controllable loading of absorbers and obtaining functional wearable absorbers with high electromagnetic response are still considered great challenges. In this work, a flexible fiber-based absorber (VF_T2h/MF/PPy) with a rich interfacial polarization relaxation was obtained by integrating heterostructures and performing nanostructure design and introducing π-conjugated polymer components. Electrons migrated and redistributed between nanoparticles and nitrogen-carbon lattices with different electrostatic states. The formed heterogeneous interface promoted the electromagnetic attenuation response in the high-frequency region. More specifically, the effective absorption frequency bandwidth was up to 5.6 GHz (corresponds to the Ku-band with a matching thickness range up to 2.55–4.85 mm). Impressively, the abundant modification sites on the fiber surface adjusted the content and dispersion of the magnetic nanoparticles and enhanced the vector superposition effect generated by the structural distribution of the magnetic/electric fields. The introduction of dielectric components improved the interfacial polarization strength of the heterojunction surface and the synergistic effect of the dipolar polarization. The high-efficiency electromagnetic attenuation performance was attributed to multiple loss mechanisms. Our work provides a reference path for the microscopic regulation of the high-efficiency electromagnetic response mechanism of fiber-based flexible absorbing materials.

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The development of wood adhesives using biomass resources holds significant importance for sustainable resource utilization and public health. Utilizing non-condensed lignin directly as a wood adhesive provides a new approach for the green, low-cost, and large-scale production of high-performance wood adhesives. This innovation has the potential to drive the green and low-carbon development of the wood/plant products industry.

Substantial challenges remain in developing fiber devices to achieve uniform and customizable photochromic lighting effects using lightweight hardware. A recent publication in Light Science & Application, spearheaded by Prof. Yan-Qing Lu and Prof. Guangming Tao presents a methodical approach to surmount the limitations in photochromic fibers. They integrated controllable photochromic fibers into various wearable devices, providing a promising path for future exploration and advancement in the field of human–machine interaction.

Organic thermoelectric fibers have great potential as wearable thermoelectric textiles because of their one-dimensional structure and high flexibility. However, the insufficient thermoelectric performance, high fabrication cost, and mechanical fragility of most organic thermoelectric fibers significantly limit their practical applications. Here, we employ a rapid and cost-effective wet-spinning method to prepare dimethyl sulfoxide-doped poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) fiber bundles, followed by rational post-treatment with concentrated sulfuric acid (98% H₂SO₄) to enhance their thermoelectric performance. The wearable fiber bundles composed of multiple individual PEDOT:PSS fibers have effectively reduced resistance and overall high tensile strength and stability. Rational treatment with H₂SO₄ partially removes excessive PSS, thereby increasing the electrical conductivity to 4464 S cm^‒1, while the parallel bundle is also a major factor in improving the power factor of up to 80.8 μW m^‒1 K^‒2, which is super-competitive compared with those of currently published studies. Besides, the thermoelectric device based on these fiber bundles exhibits high flexibility and promising output power of 2.25 nW at a temperature difference of 25 K. Our work provides insights into the fabrication of all-organic flexible high-conductivity textiles with high thermoelectric properties.

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