Recent advancements in next-generation rechargeable batteries have focused on solid-state batteries (SSBs) due to their promising potential for improved energy density and safety. Among the various types of solid electrolytes, composite solid electrolytes (CSEs), composed of fillers and salts dispersed within a polymer matrix, have gained significant attention for their balanced properties of ionic conductivity and stability toward both electrodes, making them more suitable for practical SSB applications. In CSEs, the relationship between structure, properties, and performance is crucial. Unfortunately, conventional CSEs are still limited by randomly distributed fillers and agglomeration phenomena, which may impede ion transportation. Nanofiber fillers, characterized by their long-range structure, high surface area-to-volume ratios, and high aspect ratios, have the potential to significantly enhance CSE properties. Furthermore, they can shorten the ion-migration pathway and be aligned in a single direction. In this review, current technologies related to nanofiber-based CSEs are summarized. Typically, recent strategies for nanofiber structural design and synthesis, from principles to practical applications, are systematically reviewed. Subsequently, promising approaches to implementing nanofiber-based CSEs in SSBs with superior electrochemical performance and cyclability are discussed. Thus, this review provides a comprehensive overview of the state-of-the-art nanofiber-based CSEs for high-performance SSBs, which have the potential to safely accelerate the development of next-generation rechargeable batteries.
Although the application of solar-driven interfacial evaporation technology in the field of seawater desalination has seen rapid progress in recent years, mediocre water evaporation rates remain a longstanding bottleneck. The key to resolving this bottleneck is leveraging strong hydrogen bonding to reduce the enthalpy of evaporation for water molecules and inputting environmental energy. This study presents a novel approach for reducing the enthalpy of vaporization by introducing a hydrophilic inorganic material Al(H2PO4)3 (AP) on the surface of cellulose nanofibers (CNF) to form an inorganic‒organic hydrogen-bonded network in cellulose-based hydrogels (labeled 3DL Metagel). This network structure accelerates the diffusion of water molecules between CNF, as confirmed by molecular dynamics simulations. Specifically, inspired by multiple biological traits found in nature, the 3DL Metagel evaporator integrates a lotus shape, Janus wettability (the superhydrophilic lotus-like flower with hydrophobic lotus-like leaves) and plant transpiration, resulting in superior water evaporation rates of up to 3.61 kg·m−2·h−1 under 1.0 solar radiation (exceeding the limit of two-dimensional evaporators). The unique lotus shape enables 3DL Metagel to draw additional energy from the environment during desalination, resulting in a maximum water evaporation efficiency of 94.94%. The dual porous structure with Janus wettability endows the evaporator with self-floating ability and a unidirectional salt ion reflux channel during the evaporation process, providing a salt-resistant technology for seawater desalination. Noteworthy, evaporator can be used for efficient outdoor water purification in arid areas with extremely low humidity and is biodegradable and biocompatible. The integration of an inorganic‒organic hydrogen-bonded cross-linked network and biomimetic features achieves high-efficiency photothermal water evaporation, offering novel insights for the rational design of efficient evaporators for solar desalination and wastewater purification.
Flexible multifunctional sensors have attracted much attention in applications such as physiological monitoring, smart clothing, and electronic skin. However, the visual and multifunctional humidity-strain sensors following integration face the challenges of suboptimal sensing performance, inferior durability, mutual interference, and difficulties on large-scale production. Herein, a flexible, visual, and multifunctional humidity-strain sensor based on ultra-stable perovskite luminescent filament (carbon nanotubes/sodium polyacrylate (PAAS)/perovskite/thermoplastic polyurethane (CPPT)) with coaxial structure is first introduced by the environmental-friendly wet-spinning and dip-coating method. The CPPT filaments display homogeneous and bright luminescence under 200% deformations, tunable emission spectrum, wide color gamut, and high stability due to the polymer-encapsulation effect and uniform distribution of perovskite nanocrystals. The carbon nanotubes/PAAS as the outer layer undertakes radial thickness expansion upon moisture exposure. The elastic perovskite/thermoplastic polyurethane as the core bears large deformation during stretching. The CPPT filaments achieve a resistance change of 130% in the relative humidity of 95%, fast response/recovery (3.2/4.0 s), small hysteresis (3.5%), high durability, and weak interference from temperature. Besides, it obtains a Gauge factor of 27.0 at a strain of 95–200%, fast response/recovery (0.2/0.3 s), and negligible interference from temperature. The flexible CPPT filaments not only show great potential in humidity sensing, strain sensing, and information encryption but also open up new opportunities for facile integration into more complex scenarios, such as human physiological activity monitoring with an early hazard warning.
High tensile and compressive strengths are essential for fiber-reinforced plastic utilized in complex loading conditions. However, it is challenging to produce aramid fibers with both high tensile and compressive strengths. In the present work, graphene oxide modified with p-phenylenediamine (GO-PPDA) was introduced to simultaneously increase the tensile strength (up to 6.75 GPa) and compressive strength (up to 676.8 MPa) of the heterocyclic aramid fibers. GO-PPDA covalently links polymer molecular chains via amine groups, inducing a regular alignment that enhances crystallinity and orientation. Multi-scale characterization indicates that the two-dimensional graphene oxide (GO) enhances interfacial interactions among molecular chains, nanofibers, and fibril bundles, resulting in reduced sheath-core structural disparity and increased fiber densification. Atomistic simulations demonstrate that the enhancements in orientation, densification, and interfacial interactions of the building blocks contribute to the simultaneous improvement in both the tensile and compressive strengths of composite fibers. Finally, we demonstrate that the exceptional mechanical properties of these fibers can be effectively transferred to their composite materials, which is crucial for practical applications.
The novel heterocyclic aramid fibers containing GO were prepared via in-situ polymerization and wet spinning. GO-PPDA-2/AF exhibits an ultra-high tensile strength of 6.75 GPa and compressive strength of 676.8 MPa, with high-performance tows produced in batches. These exceptional mechanical properties can be effectively transferred to composite materials.
Electromagnetic interference (EMI) is becoming commonplace with the development of modern electronics. In this work, a series of conductive polymer composite fabrics that have high EMI shielding effectiveness (SE), high mechanical strength, and resilience to adverse conditions were prepared. Crosslinked hyperbranched polyamidoamine (referred to as xHP-Qy) was used to create a conductive Ag layer tightly bound to the underlying matrix of poly(meta-phenylene isophthalamide) (PMIA). The morphology and physicochemical properties of the starting materials, intermediates, and the final PMIA/xHP-Qy/Ag fabrics were characterized extensively. The PMIA matrix and the Ag layer were connected by the xHP-Qy that had a distinct antenna-shaped structure. The lowest resistivity and highest EMI SE of the fabrics were 2.37 × 10−3 Ω·cm and 107.66 dB, respectively. It was further verified by finite element simulation that the PMIA/xHP-Qy/Ag had an exceptional EMI shielding performance. The fabrics maintained their superior performance despite harsh environments (high/low temperature, high humidity, strong acid/alkali, solvents, salt spray corrosion) or mechanical deformations (bending-stretching, winding-releasing, abrading). The developed strategy thus created access to resilient functional materials suitable for use in highly demanding scenarios.
Developing high-performance aerogels has long been a hot topic in the fields of insulation and thermal protection. Nanofiber aerogels with ultralight weight and high porosity have recently emerged as promising candidates. However, the weak inter-fiber interaction hampers the robustness of the three-dimensional network, resulting in poor overall mechanical properties that hinder their wide adoption. Herein, we propose a novel template-anchored strategy for constructing polyimide hybrid nanofiber aerogels. By utilizing self-supporting chitosan as a sacrificial template, polyimide (PI) nanofibers are directionally interconnected by chemical pre-anchoring and heat treatment, which endows the three-dimensional fiber network with good structural stability. These directly assembled nanofiber aerogels exhibit an adjustable low-density range (12.3–31.5 mg/cm3), excellent compressive resilience and fatigue resistance (with only 7.2% permanent deformation after 100 cycles at 60% strain), demonstrating good shape recovery. Moreover, the complex nanofiber pathway and porous network structure contribute to superior thermal insulation performance with low thermal conductivity (28.5–31.8 mW m−1 K−1). Furthermore, the incorporation of polyimide and silica (SiO2) imparts these hybrid aerogels with remarkable high-temperature resistance and flame retardancy. This study introduces and validates a novel approach for obtaining superelastic and lightweight aerogels, highlighting its promising potential in the realm of high-temperature thermal insulation.
Fabrics have attracted significant attention in the field of electromagnetic shielding due to their unique grid structure, high electrical conductivity, and flexibility. To enrich the research of textiles for microwave absorption, two-dimensional transition metal carbide (MXene)-enhanced reduced graphene oxide-based fabrics (MXene/RGO fabrics) were synthesized in this paper by using wet spinning–ionic cross-linking–chemical reduction strategy. MXene/RGO fabrics achieve a minimum reflection loss of − 58.3 dB at 17.6 GHz and a thickness of 2.4 mm, with an effective absorption bandwidth of 4.92 GHz. In addition, the combination of electromagnetic finite element simulation technology and test results was used to further elucidate the response mode and loss mechanism of MXene/RGO fabrics. The MXene/RGO composite fibers exhibit a tuned attenuation ability and impedance matching performance, which is attributed to the increased polarization relaxation loss caused by the large number of heterogeneous interfaces between RGO, MXene, and TiO2 particles, as well as the appropriate electrical conductivity (16.6 S/cm). MXene/RGO fibers exhibit excellent microwave absorption performance, mechanical strength (534 MPa), easy modification, and fatigue resistance, promising stable absorption of electromagnetic waves in complex environments, thereby expanding the application scenarios of fabrics in the field of microwave absorption.
A natural user interface (NUI) with ample information perception capability is a crucial element for the next-generation human–machine interaction and the development of the intelligent era. However, significant challenges remain to be solved in developing intelligent and natural interfaces with satisfactory smart sensing performance. Here, we report an NUI based on an intelligent fabric bracelet empowered with wide-range pressure detectability, enabling invisible and efficient human–machine interaction. The wide-range pressure-sensing ability of the fiber-based pressure sensor can be attributed to the coupling mechanism of contact resistance change and quantum tunneling effect. The fiber-based sensor array is then integrated with a miniaturized wireless flexible printed circuit board, forming an intelligent and compact fabric bracelet system for natural interactive applications in wireless smart home control and virtual reality. It is envisioned that the NUI based on the pressure-sensitive and intelligent fabric bracelet will significantly contribute to the development of next-generation NUIs for more diversified control and interactive applications.
Passive radiative cooling fabrics with high solar reflectance and mid-IR emissivity hold great promise for personal cooling applications. Nevertheless, most current passive radiative cooling fabrics overlook their inherent thermal conductivity, resulting in ineffective heat transfer from human skin to the environment. Herein, by constructing highly anisotropic thermal conductive thermoplastic polyurethane/boron nitride nanosheet (TPU/BNNS) fabrics via one-step electrospinning, thermal conductive cooling mechanism was introduced into passive radiative cooling fabrics. The stacked TPU/BNNS nanofibers with aligned BNNS along the fiber direction and the porous fiber network with high contact thermal resistance resulted in high thermal conductivity along the in-plane direction but low thermal conductivity along the out-of-plane direction. This high anisotropy enables rapid heat transfer along the in-plane direction to dissipate heat while blocking external heat penetration along the out-of-plane direction, thus achieving an effective conductive cooling effect. Moreover, the incorporation of BNNS increased the scattering sites for solar radiation, further improving the fabric’s solar reflectivity to 95%. Combined with the high emissivity (92.9%) provided by the intrinsic groups of TPU and BNNS, the fabric demonstrates excellent radiative cooling ability. Therefore, under the dual action of passive radiative cooling and conductive cooling, the TPU/BNNS fabric achieved a sub-environmental cooling of 12.4 °C and a personal cooling of 10.7 °C. Along with excellent breathability, stretchability, and waterproof properties, the TPU/BNNS fabric exhibits outstanding potential for outdoor personal thermal management applications.
Silicon carbide (SiC) porous materials possess exceptional electromagnetic wave absorption capabilities. In recent years, various SiC-based wave-absorbing materials have been developed. However, their inherent brittleness restricts their applications, posing an ongoing challenge in balancing wave absorption with mechanical performance. Herein, a templated chemical vapor deposition strategy was employed to fabricate hierarchical hollow SiC micro/nanofiber sponges (HHSMSs). The directional growth and orderly arrangement of SiC nanorods on the template fibers construct a micro–nano-structured SiC shell layer. By controlling the reaction time, the thickness of this shell layer can be tuned between 0.4 and 3.1 µm. Moreover, during the deposition process, an amorphous SiOx structure tends to form on the outer surface of the fibers. Owing to this amorphous SiOx structure, HHSMSs demonstrate excellent flexibility and elasticity, allowing them to be bent by 180° and compressed by 60%. In addition, the hierarchical hollow structure enhances impedance matching, resulting in superior electromagnetic wave absorption with a minimum reflection loss of −51.8 dB and an ultra-wide effective absorption bandwidth (EAB) of 8.6 GHz. These properties highlight the potential of these flexible, broadband-absorbing sponges for stealth and electromagnetic interference shielding in high-temperature environments.
Compared with those traditional initiating devices of anti-scalding systems, ionic thermoelectric sensors with energy-autonomous performance show higher reliability. However, the current ionic thermoelectric materials (i-TEs) suffer from complex nano-/micro-channel design, high production costs, environmentally unfriendly, weak mechanical properties, as well as the low moving speed of ions. Herein, the functional leather collagen fibers-bearing natural channels are employed as the polymer matrixes, while the trisodium citrate (SC) organic acid salt exhibits the function of cationic moving self-enhancement as the primary mobile ions for signaling. Including numerous and suitable nano-/micro-channels together with fast-moving cations, the leather-based i-TEs (LITE), LITE-SC0.75 M, possess excellent thermoelectric properties, achieving a Seebeck coefficient of 6.23 mV/K, a figure of merit of 0.084, and an energy conversion efficiency of 2.12%. Combined with its excellent thermal stability, mechanical performance, flexibility, durability, low cost, and outstanding capabilities for low-grade heat harvesting and thermal sensing, the LITE-SC0.75 M detector bearing long service life would show great promise in automatic anti-scalding alarm suitable for multiple scenarios and extreme environments. Therefore, the present work aims to design an efficient, robust, and energy-autonomous leather collagen fibers-based thermoelectric detector to address the limitation of current anti-scalding alarm technology as well as drive advancements in the nano-energy and its effective conversion field.
The robust leather collagen fibers-based ionic thermoelectric (i-TEs) detectors with numerous nano-/micro-channels and fast-moving cations are successfully constructed, which demonstrate great potential for automatic anti-scalding applications in various scenarios and extreme environments
The development of the highly stretchable and strain-insensitive conductive fibers exhibiting extremely small resistance change under large deformation is crucial for the electronic signal stability in the smart wearable fields. In this paper, an all-polymeric conductive microfiber (PU@PVA-PEDOT:PSS SI-CF) with desirable performances has been developed by using microfluidic spinning technology (MST), during which process the instinct strain-insensitive conductive polymer hydrogel core with semi-interpenetrating network is constructed into the helical structure. The configuration and performances of the PU@PVA-PEDOT:PSS SI-CF have been optimized by regulating the processing parameters of MST, and the fabricated microfiber exhibits excellent stretchability (up to 500%), high conductivity (147 S cm−1), super conductance strain insensitivity (ultra-low resistance change of 5% at 100% strain), as well as excellent durability (2000 stretching-releasing cycles). The PU@PVA-PEDOT:PSS SI-CF shows great smart wearable application potential as the stretchable wire, the self-powered sensor, and the electro-thermal heater.
Rehabilitation devices that integrate pressure sensors can measure vital metrics such as muscle activities and body posture, allowing patients to perform rehabilitation exercises independently without the need for constant professional oversight. However, traditional devices are commonly constructed based on thin-film plastics and rely on external power sources that are housed in bulky encapsulation cases, compromising user inconvenience and discomfort when worn for rehabilitation activities. While textile-based sensors with self-powering capabilities offer comfort and mobility without external power sources, their sensitivity and sensing range for pressure changes fall short compared to those counterparts. To address this challenge, we herein introduce a skin-inspired, permeable, structure-gradient fiber mat (SGFM) for triboelectric pressure-sensing textiles. Permeable SGFM, created through template-assisted layer-by-layer electrospinning, mimics human skin's rigidity-to-softness mechanical transition. Such a structural design can effectively enhance the dielectric and compressive properties of SGFM, thereby significantly enhancing the sensitivity of the SGFM-based triboelectric pressure sensing textiles over a broad sensing range (0.068 kPa−1 in 0–53 kPa, 0.013 kPa−1 in 53–660 kPa). Notably, the electrospun fibrous structure of SGFM provides pressure sensing textiles with promising moisture permeability, ensuring a comfortable wearing experience. As a proof-of-concept demonstration of applications, SGFM was incorporated into a wearable rehabilitation monitoring system to detect quadriceps, pulse, and plantar pressures for posture tracking and correction, displaying substantial potential for enhancing the efficiency of rehabilitation assistance.
A permeable, multilayered structure-gradient fiber mat (SGFM) for triboelectric pressure-sensing textiles is proposed. Permeable SGFM, created through template-assisted layer-by-layer electrospinning, mimics human skin's rigidity-to-softness mechanical transition. Such a structural design can effectively enhance the sensitivity of the SGFM-based triboelectric pressure sensing textiles over a broad sensing range. As a proof-of-concept demonstration of applications, SGFM was incorporated into a wearable rehabilitation monitoring system to detect quadriceps, pulse, and plantar pressures for posture tracking and correction, displaying substantial potential for enhancing the efficiency of rehabilitation assistance.
Stretchable organic light-emitting diodes (OLEDs) are emerging as a key technology for next-generation wearable devices due to their uniform light emission, stable performance under stretching conditions, and various flexible substrates. This paper introduces stretchable OLEDs fabricated with laser-cut kirigami patterns and a multifunctional encapsulation multilayer (MEM) barrier. These OLEDs were subsequently transferred onto textiles. These stretchable OLEDs achieved a remarkable stretchability of up to 150% through optimized kirigami pattern and maintained 100% stretchability when integrated with textiles, preserving the flexibility of a textile substrate. Additionally, the MEM barrier provided ultraviolet (UV) reflection and waterproof properties, ensuring reliable performance in harsh environments. Stretchable OLEDs and stretchable fabric OLEDs demonstrated a high luminance of 18,983 cd/m2 and 10,205 cd/m2, with minimal emission variation under stretched conditions. Furthermore, the potential of stretchable fabric OLEDs for wearable healthcare applications was evaluated by measuring photoplethysmography (PPG) signals. Stable PPG signals were successfully obtained at a 20% stretched state. Adjusting light source intensity effectively compensated for signal quality degradation caused by stretching. These findings highlight the significant potential of stretchable fabric OLEDs for wearable devices and photodiagnostic platforms, offering broad applicability across diverse fields.
As emerging wearables, triboelectric textiles offer dual functionalities for sensing and energy harvesting, but often encounter challenges of alternating signal generation and high internal impedance. Recent advancements in tribovoltaic textile development still show limitations in device configuration and garment integration, and consequently in human motion tracking. Herein, we report a stretchable and robust all-in-one tribovoltaic textile (SR-ATVT) featuring a three-dimensional braided core–shell architecture. Due to the Schottky contact between the metal core and semiconductor shell, SR-ATVTs consistently produce self-rectifying direct current output throughout stretching–releasing cycles. The demonstrated SR-ATVT exhibits remarkable output stability under real-use-oriented scenarios (within 10 washing rounds, after 2600 continuous cycles, and over a 4-month storage period) and serves as both angle sensor and fitness tracker when further integrated into clothing. This study presents a pioneering approach to device configuration and wearable application of tribovoltaic textiles, paving the way for the development of next-generation smart triboelectric wearables.
Lead-free barium titanate (BaTiO3) nanofiber material is an attractive functional material. However, as a ceramic material, its inherent brittleness significantly limits its widespread application. Herein, we optimized the solution blow spinning process using aerodynamic simulations, enabling the efficient fabrication of layered barium titanate/aluminum oxide (BaTiO3/Al2O3) ceramic nanofiber aerogels. The incorporation of amorphous Al2O3 repaired the defects in the nanofibers, providing aerogels with outstanding mechanical properties. For example, these aerogels can support nearly 1000 times their own weight, exhibit a tensile strain of 11%, and demonstrate exceptional compressive resilience and fatigue resistance. Additionally, the aerogels demonstrated superior performance in flexible electronics, thermal protection, sound absorption, and high-temperature filtration. This research paves the way for the large-scale production and extensive application of flexible piezoelectric ceramic aerogels.
Major challenge of developing bifunctional electrocatalyst for rechargeable Zn–air batteries (ZABs) is their structural instability and inferior electrochemical performance. To solve these issues, we propose the strategy of anchoring ZIF-derived CrFe-codoped Co nanoparticles (NPs) into the wrinkled graphene nanoscroll-fibers (WGNF) to synthesize the CoCrFe@WGNF as bifunctional catalysts for ZABs. The CoCrFe@WGNF catalyst exhibits decent oxygen evolution and reduction performance in an alkaline medium, and the resulting ZABs deliver exceptional cycling stability up to 1140 h at 5 mA·cm−2, superior to the ones based on CoCrFe (340 h) and Pt/C + RuO2 (220 h). Meanwhile, the assembled solid-state ZABs with PAM hydrogel as electrolytes exhibit excellent cycling durability and high-power density at both room-temperature and -40 ºC. The excellent stability originates from the unique wrinkled structure of graphene nanoscroll-fibers and CrFe co-doping. The graphene nanoscroll-fibers with abundant wrinkles and tubular channel can serve as a platform for anchoring to NPs by avoiding aggregation and dissolution of NPs, while the co-dopping of Cr and Fe may optimize the electronic structure of Co to boost the performance of ZABs with wide-temperature range. In short, we believe that the WGNF can be considered as an excellent support platform to encapsulate NPs for other target reactions.
CrFe-doping Co NPs were anchored into ultralong graphene nanoscroll-fibers with 1D wrinkles and ultrathin layer (CoCrFe@WGNF). The assembled liquid and solid-state ZABs showed long-life durability and high-power density even under deformation and at − 40 °C, mainly attributed to the carrier and protection effect of wrinkled graphene nanoscroll-fibers and the CrFe co-doping induced electronic coupling
Silver-based materials are renowned for their superior electrical conductivity and dielectric loss, which enhance electromagnetic (EM) shielding. However, challenges such as poor impedance matching and lack of flexibility limit their practical deployment. Microstructural engineering may hold the key to overcoming these hurdles by allowing precise control over impedance and loss properties, yet developing such materials that are both lightweight and flexible remains a formidable challenge. Herein, we developed a silver-doped flexible electromagnetic (EM) shielding porous membrane (PMA-3-1000) using a dynamic pyrolysis approach applied to a metal-azolate polymer. This method precisely controls porosity and conductivity, enhancing silver integration for exceptional EM shielding, achieving − 57 dB effectiveness and 99.998% efficiency. The membrane also demonstrates excellent performance in Joule heating and rapid photothermal conversion, reaching 110 °C in just 10 s under 1 kW/m2. The Ag-doped porous fibers in a 3D dense structure synergistically enhance multi-reflection attenuation and electrical conductivity, while the localized surface plasmon resonance (LSPR) effect from silver nanoparticles boosts Joule heating and photothermal properties. This lightweight and versatile membrane shows immense potential for military, aerospace and other high-performance applications, heralding new opportunities for multifunctional electromagnetic shielding solutions.
TOC The utility model pertains to a multifunctional porous nanofiber film that integrates electromagnetic shielding capabilities, Joule heating properties, photothermal characteristics, and light hydrophobicity.