Solid-state Fiber Research Articles

High-performance flexible zinc-ion battery: Slurry-coated on carbon fiber

Aqueous zinc-ion batteries (ZIBs) have garnered remarkable attention owing to high safety, low price, environmental friendliness, and versatile adaptability. In this paper, we present the fabrication of a fiber-based ZIB using a slurry composed of ZnVOH and carbon black as the cathode material. This battery demonstrates high capacity and a robust bonding interface. Notably, the binding strength and uniformity of the slurry on the fiber surface play a pivotal role in energy-storage capabilities. Carbon black serves the dual purpose of providing a conductive medium and a viscosity adherence to the fiber surface. ZIBs containing 15 % carbon black exhibit a high capacity of 319.8 mAh g−1 at a current density of 0.5 A g−1. In addition, the fully solid-state fiber battery demonstrates superior electrochemical performance under various bending deformations coupled with optimized electrical conductivity. Importantly, its seamless integration with textiles underscores its potential for large-scale industrial production of flexible fiber-shaped ZIBs, providing a compelling solution for flexible energy storage.

Electrochemically exfoliated graphene oxide enhanced hybrid fibers with high rate performance for fibrous supercapacitors

In this study, a composite graphene fiber was created using electrochemically exfoliated graphene oxide (EGO) and chemically oxidized graphene oxide (GO) through a simple wet spinning process. The incorporation of EGO sheets in the fiber forms a highly conductive network, significantly enhancing its conductivity. The optimized EGO/GO fiber exhibits both high areal capacitance (532 mF cm−2) and volumetric capacitance (103 F cm−3). Moreover, the EGO/GO composite fiber demonstrates superior capacitance retention and increased fiber length compared to the GO fiber. A solid-state device was also constructed by the optimized EGO/GO fiber using PVA/H2SO4 gel electrolyte which demonstrates excellent flexibility. And the as prepared solid-state fiber shaped supercapacitor demonstrates an areal capacitance of 246 mF cm−2 at a current density of 0.69 mA cm−2, while maintains 185 mF cm−2 at a current density of 34.7 mA cm−2 showcasing excellent rate performance.

Multi-functional zeolitic imidazolate framework-67 (ZIF-67) for solid-state fiber energy harvesting and storage devices

Wearable electronic devices using energy device-based smart fibers have brought changes in Internet of Things (IoT) technology paradigms. Since electric power is essential to drive all current electronic devices, a flexible energy device is essential to construct a wearable energy systems. Herein, two different types of the fiber-based energy devices were manufactured using ZIF-67, which can improve catalytic properties. First of all, it was confirmed that ZIF-67 was adsorbed on the electrodes of the solid-state fiber-shaped supercapacitor (SS-FSC) and the catalytic property was enhanced, thereby improving the specific capacitance. Second, it was verified that ZIF-67 was adsorbed on the surface of Pt wire, which is the counter electrode (CE) of the solid-state fiber dye-sensitized solar cell (SS-FDSSC), to improve the catalytic properties, resulting in the improvement of the power conversion efficiency (PCE) of the SS-FDSSCs. The optimized SS-FDSSC demonstrated enhanced electrocatalytic activity, with a PCE of up to 7.03%, which is about 40% greater than that of the pristine Pt wire electrode (5.02%). Therefore, the fiber-based energy devices functionalized with ZIF-67 with excellent catalytic properties and high surface area have been identified as having great potential for producing novel and efficient power sources for wearable electronic devices to be utilized in IoT applications.

Generation of 48 fs, 1 GHz Fundamentally Mode-Locked Pulses Directly from an Yb-doped “Solid-State Fiber Laser”

We demonstrate a fundamentally mode-locked Yb-doped “solid-state fiber laser” with a repetition rate of 1 GHz and a pulse duration of 48 fs. The nonlinear-polarization-evolution (NPE) mode-locking of the “solid-state fiber laser” enables up to 286 mW of average power and a 26 nm spectrum bandwidth, which supports a 48 fs pulse duration. The laser self-starts and the central wavelength can be tuned from 1032.4 nm to 1035.6 nm. To the best of our knowledge, it is the shortest pulse duration directly obtained by GHz fundamentally mode-locked Yb-fiber lasers.

Efficient charge transport in a solid electrolyte with percolated Pt for solid-state fiber dye-sensitized solar cells

Percolation effect introduced solid-state electrolyte is fabricated by metal sputtering process on the surface of Li-TFSI film. The percolation effect could provide efficient electron extraction through the solid electrolyte surface.

Solid-State Fiber Laser of the Yellow Spectral Range on the Rhodamine 6G Dye with an Optical Fiber Amplifier for the Formation of Sodium “Laser Guide Stars”

Solid-State Fiber Laser of the Yellow Spectral Range on the Rhodamine 6G Dye with an Optical Fiber Amplifier for the Formation of Sodium “Laser Guide Stars”

Attosecond timing jitter from high repetition rate femtosecond “solid-state fiber lasers”

Compact, high repetition rate ( ∼ G H z level) femtosecond fiber lasers are attractive for high-precision, high-speed scientific and engineering fields. However, the noise of such a laser seems far higher than low repetition rate ones, which limits its application. Motivated by this challenge, we combined the solid state and the fiber laser into a novel and highly stable “solid-state fiber laser” operating at 840 MHz repetition rate. Benefitting from the robust architecture of “optical cubes,” the laser shows an ultralow timing jitter (130 as) in free-running operation. This is the first time the timing jitter of a high repetition rate fiber laser has been brought to the attosecond level, to the best of our knowledge. This breakthrough makes an impact on the concept that the high repetition rate is associated with high timing jitter in fiber lasers and opens the way for real-world applications of these lasers.

High efficiency and stable solid-state fiber dye-sensitized solar cells obtained using TiO2 photoanodes enhanced with metal organic frameworks

Solid-state fiber dye-sensitized solar cells (SS-FDSSCs) have been the subject of intensive attention and development in recent years. Although this field is only in its infancy, metal–organic frameworks (MOFs) are one such material that has been utilized to further improve the power conversion efficiency of solar cells. In this study, MOF-integrated DSSCs were shown to have potential in the development of solar cell devices with efficiency comparable to or better than that of conventional solar cells. The power conversion efficiency (PCE) of SS-FDSSCs was improved by embedding MOF-801 into a mesoporous-TiO2 (mp-TiO2) layer, which was used as a photoanode in SS-FDSSCs, which are inherently flexible. The PCE of the MOF-integrated SS-FDSSCs was 6.50%, which is comparable to that of the reference devices (4.19%). The MOF-801 enhanced SS-FDSSCs decreased the series resistance (Rs) value, resulting in effective electron extraction with improved short-circuit current density (JSC), while also increasing the shunt resistance (Rsh) value to prevent the recombination of photo-induced electrons. The result is an improved fill factor and, consequently, a higher value for the PCE.

Highly efficient and stable solid-state fiber dye-sensitized solar cells with Ag-decorated SiO2 nanoparticles

Highly efficient and stable solid-state fiber dye-sensitized solar cells with Ag-decorated SiO2 nanoparticles

Research progress of high power semiconductor laser pump source

High power semiconductor lasers are the main pump source for solid-state lasers and fiber lasers. The improvement in the performance of laser pump sources directly promotes the development of solid-state lasers, fiber lasers and other lasers. The article introduces the latest research progress of 8xx nm and 9xx nm semiconductor laser pump sources. The output power research level of 8xx nm single-emitter laser has reached 18.8 W@95 µm, the output power research level of 8xx nm laser bar has reached 1.8 kW(QCW), the output power research level of 9xx nm single-emitter laser has reached 35 W@100 µm, the output power research level of 9xx nm laser bar has reached 1.98 kW(QCW). The output power of a narrow linewidth semiconductor laser with a linewidth ＜1 nm can reach 14 W. The development trend of semiconductor laser pump source in the future is forecasted.

Synthesis, processability and photoluminescence of pyrene-containing polyimides

Summary Four different contents of pyrene group were introduced in polyimide (PI) backbone via one step polycondensation procedure. The chemical structure, thermal property, process ability, and photophysical performance of polymers were characterized and analyzed. The obtained PIs exhibited high glass-transition temperatures from 270 to 285 °C, and weight remainder rates of PIs were all above 50% at 800 °C in N2. Fluorescence detection of metal ions was taken by adding Cu2+, Pb2+, Cr3+, Cd2+, Fe3+, Co2+, and Ni2+ to polymer solutions. It was interesting to found that the polymer exhibited significant luminescence emission “turn-on” response to Cu2+ and fluorescence emission quenching to Fe3+. Furthermore, the uniform morphologies of pyrene-containing PI fibers were prepared via electrospinning technique for investigating their optical properties in solid state. The fluorescent images and optical photographs indicated that the luminescence stability of polymers in fiber solid state was decided by both the chromophore in macromolecular chain and effective draft of polymer chains during spinning process. This study provided a facility strategy for controlling the morphology structure of materials and keeping the PL emission intensity in flexible devices.

Pt-free, cost-effective and efficient counter electrode with carbon nanotube yarn for solid-state fiber dye-sensitized solar cells

Fiber-shaped solar cells have attracted significant attention for their potential applications in portable and wearable electronics. Developing highly efficient and stable counter electrodes (CEs) to replace rare and expensive noble metals in dye-sensitized solar cells (DSSCs) is a research challenge. The low cost, excellent activity, and stability of carbon materials make them the most qualified noble-metal-free CEs for the commercialization of photovoltaic devices. In this study, we incorporated a carbon nanotube yarn (CNTY) as a CE for efficient and stable solid-state fiber-shaped DSSCs. After device optimization, the power conversion efficiency with the CNTY fiber-shaped DSSCs was approximately 4.00%, which is comparable to that of devices with platinum electrodes (2.64%). The superior mechanical property and performance stability after repeated bending, cleaning, and high output voltage for in-series connection suggest that the proposed CNTY fiber-shaped DSSCs may find applications as flexible power sources in next-generation flexible/wearable fiber electronics and energy textiles.

Continuous wave Fe2+:ZnSe mid-IR optical fiber lasers.

Today fiber lasers in the visible to near-infrared region of the spectrum are well known, however mid-infrared fiber lasers have only recently approached the same commercial availability and power output. There has been a push to fabricate optical fiber lasers out of crystalline materials which have superior mid-IR performance and the ability to directly generate mid-IR light. However, these materials cannot currently be fabricated into an optical fiber via traditional means. We have used high pressure chemical vapor deposition (HPCVD) to deposit Fe2+:ZnSe into a silica optical fiber template. These deposited structures have been found to exhibit laser threshold behavior and emit CW mid-IR laser light with a central wavelength of 4.12 µm. This is the first reported solid state fiber laser with direct laser emission generated beyond 4 µm and represents a new frontier of possibility in mid-IR laser development.

6.16% Efficiency of Solid-State Fiber Dye-Sensitized Solar Cells Based on LiTFSI Electrolytes with Novel TEMPOL Derivatives

Dye-sensitized solar cells (DSSCs) have attracted intense scientific interest due to their low cost, environmentally friendly operation, and relatively high efficiency. In particular, solid-state f...

Scalable preparation of high performance fibrous electrodes with bio-inspired compact core-fluffy sheath structure for wearable supercapacitors

Thanks to their light-weight, wearing comfort, and amenability to be woven into textiles, solid-state fiber supercapacitors (FSCs) have been considered as promising energy storage devices for wearable electronics. Carbon fibers (CFs) have the merits of both superior mechanical strength and conductivity, excellent flexibility, doped by heteroatoms, good knittability/weavability, and most importantly have already been produced in ton-scale in form of continuous tows; however, their applications in FSCs are limited to current collectors or conductive scaffolds as a result of the inert surface composed of highly compacted and well-aligned graphitic sheath. Inspired by Cattail’s unique compact core-fluffy sheath structure, herein, we develop an electrochemical method to directly transform CFs into high performance electrode by controllably swelling the well-aligned graphitic sheath without disturbing the core fiber of interlinked randomly-orientated carbon nanocrystals. Compared to pristine CFs, the obtained fiber electrode delivers more than two-order improved capacitance (87.2 F cm−3 at 1.0 A cm−3) with excellent rate capability and cycling stability, enabling the as-fabricated solid-state supercapacitor much enhanced energy density. The scalability of our method is demonstrated, which is believed to be compatible with the state-of-art commercial processing techniques, thus holds great promise for future development of electronic-textiles.

Improving the rate capability of ultrathin NiCo-LDH nanoflakes and FeOOH nanosheets on surface electrochemically modified graphite fibers for flexible asymmetric supercapacitors

A fiber asymmetric supercapacitor system is designed with NiCo-LDH nanoflakes and FeOOH nanosheets anchored on electrochemically activated graphite fibers as positive electrode and negative electrode, respectively. Due to the formation of COMetal bonding, the oxygen-functionalized carbon on electrochemically activated graphite fibers can bind strongly with NiCo-LDH and FeOOH, which assists in establishing the fast electron transfer routes and fluent ion transport avenues. Both NiCo-LDH and FeOOH anchored on electrochemically activated graphite fibers display a high rate performance, 80% and 87.3% of the electric capacity can be reserved with the current density increasing from 2 to 20 A g−1 and 2 to 10 A g−1, respectively, while the NiCo-LDH and FeOOH deposited on untreated graphite fibers can only retain 45% and 40%. The fabricated novel solid-state fiber asymmetric supercapacitor device exhibits an expanded operation potential window of 1.8 V with a maximum energy density (130 W h kg−1) when the power density is 1.8 kW kg−1. Furthermore, a high energy density (81 W h kg−1) is still achieved at a superhigh power density (10.8 kW kg−1). Additionally, a good cycling stability of the solid-state fiber asymmetric supercapacitor can be obtained (90% capacity retention after 10,000 cycles).

A core-sheath holey graphene/graphite composite fiber intercalated with MoS2 nanosheets for high-performance fiber supercapacitors

One-dimensional fiber-shaped supercapacitors have recently attracted lots of attention as a potential energy storage solution for emerging wearable devices. However, fiber supercapacitors often exhibit low energy storage capacity and poor rate capability due to their small volume, low specific volumetric capacitance, and poor electrode electrical conductivity. Here we demonstrate a novel hydrothermally assembled core-sheath fiber comprised of a graphite fiber core and a MoS2 nanosheet intercalated holey graphene oxide (HGO) sheath as electrodes for fiber supercapacitors. HGO and MoS2 nanosheets self-assemble around the graphite fiber core in a space-confined reactor during the hydrothermal synthesis. HGO nanosheets supply abundance channels for electrolyte ion transfer, MoS2 nanosheets provide large pseudocapacitance, and graphite fibers serve as faster electron transfer highways. The mass loading of MoS2 is easily tunable. The optimized composite fiber with 34.9 wt% MoS2 delivers a high volumetric capacitance 421 F cm−3 at the CV scan rate of 5 mV s−1 and the capacitance retention of 51.0% when the scan rate increases from 2 to 100 mV s−1. The core-sheath fiber enables fast reversible redox kinetics, and its surface capacitive energy storage contributes ∼75–80% of its total energy storage. The assembled solid-state fiber supercapacitor delivers a high device volumetric capacitance of 94 F cm−3 at 0.1 A cm−3 and an energy density of 8.2 mWh cm−3 at the power density of 40 mW cm−3, outperforming many recently reported fiber supercapacitors. The core-sheath fiber electrode design based on HGO, MoS2 and graphite fiber cores provides an efficient platform for designing various novel fiber electrodes for potential electrochemical applications.

Effects of laser heat treatment combined with ultrasonic impact treatment on the surface topography and hardness of carbon steel AISI 1045

The surface layers of medium-carbon steel AISI 1045 were hardened by laser heat treatment (LHT) and by ultrasonic impact treatment (UIT) applied separately and in different sequences. The advantages of the two latter combined laser-ultrasonic hardening and finishing methods (the LHT + UIT and UIT + LHT combined treatments) are also analyzed in this work. The laser transformation hardening process was implemented using a 1 kW solid-state fiber laser with scanning optics and a proportional integral derivative (PID) closed-loop temperature control. The ultrasonic strain hardening process was carried out by means of a 0.3 kW ultrasonic generator and an ultrasonic oscillatory system, which contained a piezoceramic transducer, step-like horn and the impact head with seven cylindrical pins. The single-path processes were studied. The separately applied LHT and UIT process were firstly analyzed using a response surface method (RSM) and the analysis of variance (ANOVA). The effects of the heating temperature (1050–1300 °C) and the specimen feed rate (40–140 mm/min) used at the LHT process on the features of the hardened zone and surface hardness/microhardness of subsurface layer were assessed. The effects of the vibration amplitude of ultrasonic horn (15–18 μm) and treatment duration (60–240 s) at UIT on the surface roughness/waviness and hardness were also investigated. The experimental plan is based on a miscellaneous design matrix method. The quadratic regression equations for predicting the studied output parameters were developed and the optimum regimes of the LHT and UIT processes were determined based on the highest surface hardness and minimum roughness/waviness. Then, the influences of the combined treatments on the surface topography and hardness were analyzed and compared to those of single LHT and single UIT processes. Results show that the combined treatments provide more than triple increase in the surface hardness in comparison with that of the initial state, as well as formation a regular microrelief with minimum surface roughness.

Hierarchical nanothorns MnCo2O4 grown on porous/dense Ni bi-layers coated Cu wire current collectors for high performance flexible solid-state fiber supercapacitors

Cu wires are coated by porous/dense Ni bi-layers as current collectors through electroless plating and hydrogen bubble dynamic template electrodepostion methods. The unique coaxial composite current collectors can be beneficial from the high electrical/thermal conductivity of metal Cu core and high corrosion resistance of dense metal Ni coating as well as porous Ni substrate for growth of active materials. Furthermore, the metal wire current collectors have excellent flexibility and mechanical strength. Highly flexible solid-state fiber supercapacitors are then fabricated by binder-free integrated electrodes of hierarchical MnCo2O4 nanothorns grown on porous/dense Ni bi-layers coated Cu wires. The fiber supercapacitors reach capacitance of 20.6 mF cm−1 (54.8 mF cm−2) and energy density of 4.8 μWh cm−1 (12.8 μWh cm−2) at a power density of 32.25 μW cm−1 (110 μW cm−2). Moreover, the twist fiber supercapacitors show good rate capability and cycling stability. The outstanding performances of the fiber supercapacitors might be attributed to the hierarchically nanothorns MnCo2O4 active materials and the unique porous/dense Ni coated Cu wire current collectors. Our results can provide a novel strategy to design flexible nanostructure fiber supercapacitors for energy storage applications in future wearable electronics.

All-fibre Q-switching YDFL operation with bismuth-doped fibre as saturable absorber

We demonstrate the generation of a passively Q-switched ytterbium-doped fibre laser (YDFL) using a bismuth-doped fibre (BDF) as a solid-state fibre saturable absorber (FSA) in a ring cavity. The BDF used has a wide and low absorption band of 5 dB/m at the 1.0 μm region due to the ion transition of that occurs around the region. When introduced into a YDFL laser cavity, a stable Q-switched pulse operation was observed and the pulse repetition rate was proportional to the input pump power. It was limited to 72.99 kHz by the maximum power that the laser diode could supply. Meanwhile, the pulse width decreased from 12.22 to 4.85 μs as the pump power was increased from 215.6 to 475.6 mW. The finding suggests that BDF could be used as a potential SA for the development of robust, compact, efficient and low cost Q-switched fibre lasers operating at 1 micron region.