Fiber Anode Research Articles

Free-standing medium-entropy porous needle-like FeCoCuNi phosphide nanowires-formed flower clusters/carbon fiber anode with high capacity and long durability for sodium-ion batteries

The drastic volume expansion and slow sodium-ion kinetics hinder the practical application of phosphides with high specific capacity and low discharge voltage in sodium-ion batteries (SIBs). Herein, we introduced entropy configuration into nanostructures and prepared a novel free-standing, three-dimensional, porous needle-like medium-entropy Fe, Co, Cu, Ni phosphide (ME-FCCNP) nanowires-formed flower clusters/carbon fiber cloth (CFC) anode (ME-FCCNP@CFC) for SIBs. The distorted lattices caused by medium-entropy configuration provide abundant sites for sodium-ion reactions and improve the electron transfer rate. The medium-entropy effects improve the mechanical stability, while the three-dimensional networks and porous needle-like nanowires provide sufficient space for the volume expansion. These combined properties enable the ME-FCCNP@CFC electrode to exhibit a high-rate capability of 170.8 mAh g−1 at 5.0 A g−1 and deliver a specific capacity of 325.8 mAh g−1 after 2000 cycles at 2.0 A g−1, far surpassing most of reported transition-metal phosphides. Moreover, the Na3V2(PO4)3 || ME-FCCNP@CFC full cell showcases a high-energy density of 256.8 Wh kg−1 and a long cycling life (267.8 mAh g−1 at 2.0 A g−1 with a capacity retention of 83.2 % after 1000 cycles). These results provide significantly promising implications for the anode design of SIBs by employing self-supporting and medium-entropy structures.

Investigation of the Durability of a Water Electrolysis Cell with Iridium Fiber Anode Against Voltage Fluctuations Simulating Wind Power

Durability of a water electrolysis cell against the voltage fluctuations is focused on in this study. An accelerated potential fluctuation test was performed for a newly developed MEA with Iridium fiber anode in our lab. In the first 40 sets of the test, no positive effect of the fiber structure was seen, and rather the fast current loss related to gas stagnation was observed. That was assumed to be owing to the coverage on inter-fiber pores by extra Nafion® ionomer. However, in the latter 40 sets, the expansion of the anode layer was confirmed by SEM images, and the rate of gas stagnation was decreased. Furthermore, the recovery of I-V performance after the rest period was sufficiently good, and almost no irreversible degradation was considered. Therefore, the Iridium fiber anode most likely has high durability against the increased internal pressure in the anode layer derived by stagnated gases.

Highly matched electrode for all-solid-state sodium-ion fiber hybrid supercapacitor with wide temperature and high energy density

In order to solve the kinetic mismatch problem of hybrid supercapacitors, a simple and effective assembly technology for wide temperature all-solid-state sodium-ion fiber hybrid supercapacitor is proposed based on anode and cathode with optimal volume capacity ratio and complementary potential windows. Ti3C2Tx fiber anode is produced by wet spinning in acetic acid bath. It reveals an excellent volume capacity of 406 F cm−3, good cycle stability of 90 % retention in 1 M NaClO4 electrolyte, high conductivity of 3303 S cm−1, and tensile strength of 80 MPa. NaV3O8/rGO (NVO/rGO) fiber cathode is obtained by wet spinning and hydrothermal treating, exhibiting high matched volumetric capacitance and improved rate performance. Moreover, a wide temperature all-solid-state sodium-ion fiber hybrid supercapacitor (PVA EGHG NVO/rGO//Ti3C2Tx AFSIC) is assembled using polyvinyl alcohol ethylene glycol hydrogel (PVA EGHG) as separator and electrolyte. The AFSIC shows an outstanding volumetric specific capacitance of 76 F cm−3 at 0.1 A cm−3, and a maximum volumetric energy density of 30.6 mWh cm−3 at a power density of 83.2 mW cm−3. In addition, it can be bend to diverse degrees without significant change in its electrochemical performance. In addition, the AFSIC exhibites exceptional capacitance and outstanding flexibility in a wide temperature range of −40 to 60 °C, showing that the PVA EGHG NVO/rGO//Ti3C2Tx AFSIC has wide prospect in the area of wearable electronic components.

Effect of Supporting Carbon Fiber Anode by Activated Coconut Carbon in the Microbial Fuel Cell Fed by Molasses Decoction from Yeast Production

A microbial fuel cell (MFC) is a bioelectrochemical system that generates electrical energy using electroactive micro-organisms. These micro-organisms convert chemical energy found in substances like wastewater into electrical energy while simultaneously treating the wastewater. Thus, MFCs serve a dual purpose, generating energy and enhancing wastewater treatment processes. Due to the high construction costs of MFCs, there is an ongoing search for alternative solutions to improve their efficiency and reduce production costs. This study aimed to improvement of MFC operation and minimize MFC costs by using anode material derived from by-products. Therefore, the proton exchange membrane (PEM) was abandoned, and a stainless steel cathode and a carbon anode were used. To improve the cell’s efficiency, a carbon fiber anode supplemented with activated coconut carbon (ACCcfA) was utilized. Micro-organisms were provided with molasses decoction (a by-product of yeast production) to supply the necessary nutrients for optimal functioning. For comparison, an anode made solely of carbon fibers (CFA) and an anode composed of activated carbon grains without carbon fibers (ACCgA) were also tested. The results indicated that the ACCcfA system achieved the highest cell voltage, power density, and COD reduction efficiency (compared to the CFA and ACCgA electrodes). Additionally, the study demonstrated that incorporating activated coconut carbon significantly enhances the performance of the MFC when powered by a by-product of yeast production.

Multifunctional performances of structural battery composite full-cells based on carbon fiber anode and LiFePO4 loaded carbon fiber cathode

In this work, the structural battery composite (SBC) full-cells based on carbon fiber (CFs) were fabricated using a three-step hot pressing method. LiFePO4 (LFP) was loaded onto CF fabrics considering the influences of hot pressing parameters including the pressure and the temperature. The SBC full-cells were subsequently fabricated using the LFP loaded CF cathode, the CF anode, the glass fiber (GF) separator via a structural electrolyte (SE) filming process, followed by the second hot pressing. The multifunctional efficiencies were assessed for SBCs with SE containing different components. To reduce the capacity loss, the SBC was eventually encapsulated with the GF/Vinyl Ester prepreg and thermally cured in the third hot pressing. The capacity retention of the SBC was significantly improved after encapsulation. This work could be seen as a further step forward the engineering fabrication of the SBC full-cells based on both CF anodes and cathodes.

Insight into roles of carbon anodes for removal of refractory organic contaminants in electro-peroxone system: Mechanism, performance and stability

Electro-peroxone (EP) is a novel technique for the removal of refractory organic contaminants (ROCs), while the role of anode in this system is neglected. In this work, the EP system with graphite felt anode (EP-GF) and activated carbon fiber anode (EP-ACF) was developed to enhance ibuprofen (IBP) removal. The results showed that 91.2% and 98.6% of IBP was removed within 20 min in EP-GF and EP-ACF, respectively. Hydroxy radical (O⋅H) was identified as the dominant reactive species, contributing 80.9% and 54.0% of IBP removal in EP-ACF and EP-GF systems, respectively. The roles of adsorption in EP-ACF and direct electron transfer in EP-GF cannot be ignored. Due to the differences in mechanism, EP-GF and EP-ACF systems were suitable for the removal of O⋅H-resistant ROCs (e.g., oxalic acid and pyruvic acid) and non-O⋅H-resistant ROCs (e.g., IBP and nitrobenzene), respectively. Both systems had excellent stability relying on the introduction of oxygen functional groups on the anode, and their electrolysis energy consumption was significantly lower than that of EP-Pt system. The three degradation pathways of IBP were proposed, and the toxicity of intermediates were evaluated. In general, carbon anodes have a good application prospect in the removal of ROCs in EP systems.

Poly (vinyl alcohol) based carbon nanofibers as freestanding anodes for lithium‐ion batteries

AbstractIn this study, we investigated the iodination process for the preparation of water‐soluble polyvinyl alcohol (PVA)‐based carbon nanofibers (CNFs) and their electrochemical properties. Iodinated nanofibers were carbonized at different temperatures (600°C, 800°C) under an argon (Ar) atmosphere. Morphology and physical properties of fiber mats were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and thermogravimetric analysis (TGA), while electrical conductivity measurements were done using four probes. As a freestanding anode in half‐cell lithium batteries, the CNFs were prepared by electrospinning of PVA and PVA–CNT blend, which was exposed to iodine vapor at various temperatures (60, 80, and 100°C). Iodine vapor treatment at 80°C and subsequent carbonization at 800°C provided a 29% carbon yield. The resulting CNT‐containing optimized CNFs exhibited superior flexibility, electrical conductivity (2.16 S/cm), and handleability, making them a promising, binder‐free environmentally friendly carbon source for lithium‐ion batteries with high capacity (672 mAh/g at 50 mA/g). The study clearly showed that PVA might be an alternative precursor for the production of carbon micro‐ and nanofibers.Highlights Anodic performance of PVA‐based carbon nanofibers was analyzed. PVA precursor offers economic and environmental option for binder‐free electrodes. PVA–CNT composite nanofibers with optimized iodination and carbonization time identified as a promising high carbon yield carbon source for lithium‐ion batteries. CNT‐containing optimized carbon nanofibers exhibited superior flexibility and electrical conductivity (2.16 S/cm). Freestanding fiber anodes exhibited a higher capacity of 672 mAh/g, at 50 mA/g compared to conventional graphite anode (372 mAh/g).

Fiber‐Based Flexible Ionic Diode with High Robustness and Rectifying Performance: Toward Electronic Textile Circuits

AbstractIn response to the growing demand for wearable devices designed for seamless integration with 3D bio‐surfaces, fiber‐based devices have gained prominence in textile‐based wearable electronics due to their flexibility and unique structure. In particular, though diodes with rectifying properties are crucial for a range of electronic systems, there has been scant reporting on diodes with a fiber structure. This study introduces a fiber‐based flexible ionic diode that exhibits a rectification ratio of 2773 and an output current of 28.2 mA at 3 V. The diode is composed of a double helical Zn‐based fiber anode, a Ti‐based fiber cathode on Au nanoparticle‐based flexible fiber electrodes, and a LiCl hydrogel electrolyte. By modulating the double helical design and the ionic conductivity of the hydrogel, the electrical performance of the diode to achieve varying rectification ratios and output currents can be tailored. Owing to the remarkable flexibility and stability of the fiber electrodes, the fiber‐based ionic diode consistently upholds its rectifying capabilities, even under washing procedures and significant bending deformation. Furthermore, this diode seamlessly integrates into various electronic circuits, including half‐wave rectifiers, capacitor–diode filters, and logic gate systems.

(Energy Technology Division Walter van Schalkwijk Award in Sustainable Energy Technology Address) Exploring New Electrode Designs with Nanofibers

In recent years, electrospinning has been gaining popularity as a robust and scalable technique for the fabrication of non-woven mats of sub-micron diameter polymer fibers. Although not as well studied, the technique can also be used to prepare particle/polymer fiber networks with high intra- and inter-fiber porosity. Such fibrous mats can be used as porous electrodes in fuel cells and batteries, where a high electrode/electrolyte interfacial area is needed. In this talk, particle/polymer electrospinning will be presented as a platform technique to fabricate a variety of electrode and membrane-electrode-assembly (MEA) products with unique and desirable compositions, architectures, and performance characteristics. Laboratory results will be presented for: (1) hydrogen/air fuel cell cathodes with Pt/C and PGM-free catalysts, (2) Pt/C hydrogen electrodes in a H2/Br2 redox flow battery, and (3) Si anodes for lithium-ion batteries.High particle content fibers containing Pt/C or Pt-alloy catalyst powder and a Nafion®perfluorosulfonic acid binder have shown great promise as electrodes in H2/air fuel cells. During electrospinning, Nafion ionomer migrates to the outer edges of the fiber, effectively creating a core-shell fiber morphology, with a low I/C ratio in the fiber interior. Additionally, the interior of the fiber contains nm-size pores and the outer surface of the Nafion shell exhibits enhanced hydrophobicity, due presumably to an accumulation of the polytetrafluoroethylene backbone chains (-CF2-CF2-) of Nafion. The resulting structure is advantageous in that the majority of catalyst particles are in a low I/C environment, nanopores in the fiber interior trap electro-generated water via capillary condensation, and the hydrophobic surface of the fibers facilitates electrogenerated water removal from the mat during fuel cell operation. The fuel cell power output using fiber mat anodes and cathodes is very high for a low Pt loading (0.10 -0.20 mg/cm2), near or above 1.0 W/cm2 for H2/air feeds in the range of 60-100% relative humidity.1,2 Additionally, the fiber mat cathodes exhibit excellent durability, with minimal power loss after accelerated voltage cycling tests. The hydrophobicity of fibers can be enhanced by adding polyvinylidene fluoride (PVDF) directly to the Nafion binder. Such blended binders in fiber/particle hybrid electrodes extend the operational lifetime of fuel cells with iron-based PGM-free cathode MEAs.As an extension of the fuel cell electrode work, electrospun Pt/C-Nafion nanofiber mat hydrogen electrodes have been made and tested for a H2-Br2 redox flow battery.3 The hydrophobic surface coating of core-shell fibers effectively blocks bromine species from poisoning the hydrogen electrode. In a 6.6 M HBr electrolyte lab-scale redox flow battery, the fiber mat electrodes worked extraordinarily well, with: (i) high power at low Pt loading, e.g., 650 mW/cm2 at 0.70 Vfor a loading of 0.11 mgPt/cm2 (6.4 kW/gPt) and 550 mW/cm2 at 0.65 V for a loading of 0.048 mgPt/cm2 (11.5 kW/gPt), (ii) no loss in power for more than 170 charge/discharge cycles, and (iii) a roundtrip current efficiency of 95%at both 0.2 and 0.3 A/cm2.For Li-ion battery applications, single and dual fiber anode mats have been prepared and evaluated, where the fibers contain a polymer binder (e.g., polyacrylic acid, polyamidimide, or polyvinylidene fluoride), Si nanoparticles as the electrochemically active material, and carbon powder as an electron conductor.4 Here, the gravimetric and areal capacities of the fiber anode are considerably higher than those of a conventional carbon particle anode. Inter-fiber voids allow for volume changes in Si during lithiation/delithiation, thus minimizing capacity fade during charge/discharge cycling (up to 600 cycles).AcknowledgmentsThis work was funded by the U.S. Department of Energy, Contract No. DE-EE0007653 from the Fuel Cell Technologies Office, through the Fuel Cell Performance and Durability Consortium (Fuel Cells Program Manager: Dimitrios Papageoropoulos) and Contract No. DE-EE0007215 from the Vehicle Technology Office.

Electrochemical oxidation and mechanism of sulfanilamide from groundwater in a flow-through system using carbon fiber (CF) anode

Metal-based anodes have been used for a long time in the electrochemical oxidation processes to remediate groundwater. However, the high cost of this technique as well as the release of potentially toxic metals (ex, lead), are major barriers being fully implemented. As an alternative of metal-based anodes, in recent years, carbon-based anodes have been paid attention due to their eco-friendliness and cost-effectiveness. This study evaluated the oxidation performance of carbon fiber (CF) anode in a flow-through system. The CF anode degraded 45–87% of the target pollutant (sulfanilamide), depending on the current intensity applied. However, no further degradation of sulfanilamide was observed after the cathode, indicating that sulfanilamide degradation occurred mainly at the anode. This study also determined the effect of electrolytes on electrochemical oxidation using chloride (Cl−), sulfate (SO42−), bicarbonate (CO3−), and synthetic groundwater. Cl− and SO42− electrolytes were converted electrochemically into active species, thereby enhancing sulfanilamide degradation, while the bicarbonate and groundwater electrolytes inhibited oxidation performance by scavenging hydroxyl radicals. A series of scavenger tests and characterization showed that the direct oxidation and hydroxyl radicals involved the sulfanilamide degradation. Especially, the production of hydroxyl radicals is more favorable in high currents than in low currents. That is, CF anode contributed to the degradation by direct oxidation of carbon-based electrodes and generation of hydroxyl radicals. In summary, this study highlights how a CF anode is capable of effectively degrading organic pollutants via anodic oxidation.

Electrospun Si and Si/C Fiber Anodes for Li-Ion Batteries

Due to structural changes in silicon during lithiation/delithiation, most Li-ion battery anodes containing silicon show rapid gravimetric capacity fade upon charge/discharge cycling. Herein, we report on a new Si powder anode in the form of electrospun fibers with only poly(acrylic acid) (PAA) binder and no electrically conductive carbon. The performance of this anode was contrasted to a fiber mat composed of Si powder, PAA binder, and a small amount of carbon powder. Fiber mat electrodes were evaluated in half-cells with a Li metal counter/reference electrode. Without the addition of conductive carbon, a stable capacity of about 1500 mAh/g (normalized to the total weight of the anode) was obtained at 1C for 50 charge/discharge cycles when the areal loading of silicon was 0.30 mgSi/cm2, whereas a capacity of 800 mAh/g was obtained when the Si loading was increased to ~1.0 mgSi/cm2. On a Si weight basis, these capacities correspond to >3500 mAh/gSi. The capacities were significantly higher than those found with a slurry-cast powdered Si anode with PAA binder. There was no change in fiber anode performance (gravimetric capacity and constant capacity with cycling) when a small amount of electrically conductive carbon was added to the electrospun fiber anodes when the Si loading was ≤1.0 mgSi/cm2.

Architectural engineering of MoS2/Fe2O3@carbon fiber heterostructures to obtain ultra-stable anodes for sodium-ion batteries

Metal sulfides based on a conversion mechanism possess high theoretical specific capacity, making them suitable for high-energy-density sodium-ion batteries (SIBs). However, they suffer from rapid capacity decay when assembled into full batteries due to dynamic hysteresis and large volume expansion. In this paper, the architectural engineering approach to construct MoS2/Fe2O3 @ carbon fiber heterostructures is proposed to overcome the above issues. The heterojunction formed by MoS2 and Fe2O3 would promote ion/electron transfer, while the carbon nano-fibers serve as a holder to maintain structural stability and ensure the rapid transport of electrons. The full battery in which the as-prepared MoS2/Fe2O3 @ carbon fiber anode is paired with a Na3V2(PO4)3/C cathode delivers a reversible capacity of 61.1 mAh g−1 at 500 mA g−1 for 1600 cycles without attenuation. Experimental characterization and theoretical calculation results show that this structural engineering approach improves the ion diffusion efficiency, enhances the conductivity, provides a more appropriate sodium ion adsorption energy, and thus extends the cycling life of the SIB. This work demonstrates the efficiency of architectural engineering and paves the way to design ultra-long-cycling Na-ion batteries.

Functional Laminated Fiber Scaffold Based on Titanium Monoxide for Lithium Metal-Based Batteries.

Lithium metal-based rechargeable batteries are attracting increasing attention due to their high theoretical specific capacity and energy density. However, the dendrite growth leads to short circuits or even explosions and rapid depletion of active materials and electrolytes. Here, a functionalized and laminated scaffold (PVDF/TiO@C fiber) based on lithiophilic titanium monoxide is rationally designed to inhibit dendrite growth. Specifically, the bottom TiO@C fiber sublayer provides rich Li nucleation sites and facilitates the formation of stable solid electrolyte interphase. Together with the top lithiophobic PVDF sublayer, the prepared freestanding scaffold can effectively suppress the growth of Li dendrite and ensure stable Li plating/stripping. Based on the dendrite-free deposition, the Li/PVDF/TiO@ C fiber anode enables over 1000h at a current density of 1mA cm-2 in a symmetrical cell and delivers superior electrochemical performance in both Li || LFP and Li-S batteries. The functional laminated fiber scaffold design provides essential insights for obtaining high-performance lithium metal anodes.

Selective Electrophoretic Deposition of Silicon Nanoparticles onto PAN‐Based Carbon Fiber as a Prospective Anode for Structural Li‐Ion Batteries

AbstractThe demand for revolutionizing the lightweight design of Li‐ion batteries has become inevitable due to the ever‐increasing development of electric transportation modes. Integration of structural and energy storage functionalities into a single structural battery device can be a smart way to improve the overall performance of electric vehicles. In this study, we propose a facile and cost‐effective approach to develop a prospective anode for structural Li‐ion batteries through electrophoretic deposition of silicon (Si) particles onto polyacrylonitrile (PAN)‐based carbon fiber. The synthesis method is able to selectively deposit small‐sized silicon particles on the surface of carbon fiber, producing a thin, continuous, and porous coating of silicon nanoparticles on commercial PAN‐based carbon fiber. The synthesized Si/PAN‐based carbon fiber electrode exhibits remarkable mechanical properties, delivering a tensile strength of 2.57 GPa and a tensile modulus of 118.2 GPa. Benefitting from the morphology of the deposited silicon, the discharge capacity of silicon/PAN‐based carbon fiber anode can reach 565 mAh g−1 with 81 % capacity retention after 50 cycles. This work highlights the potential of silicon‐modified carbon fiber electrodes obtained via a simple and cost‐effective deposition method for structural Li‐ion battery applications.

Enhancing microbial fuel cell performance for sustainable treatment of palm oil mill wastewater using carbon cloth anode coated with activated carbon

Microbial fuel cells (MFCs) are a viable source of clean and renewable energy from wastewater and gaining attention on a global scale. Thus, this research work focuses on the energy production from high-strength palm oil mill wastewater using MFCs. A state-of-the-art technique for improving the performance of MFCs by covering a carbon fibre anode with various sized powdered activated carbon (PAC) particles was investigated. In addition, the MFCs were tested at various hydraulic retention times (HRT) to assess the performance displayed by modified MFCs. Results showed that a relatively smaller amount of PAC with a diameter of 13 μm coated at the anode during the cultivation stage at a shorter hydraulic retention time (4 days) would produce 504.1 ± 8.7 mW m−3 of power, 39.9 ± 2.9% of chemical oxygen demand removal efficiency, and 299 ± 63 mL of biogas. While, MFC running at a longer hydraulic retention time (12 days) was able to produce more power and had better effluent quality than those operating at a shorter hydraulic retention period.

High‐Performance Neutral Zinc‐Air Batteries Based on Hybrid Zinc/Carbon Nanotube Fiber Anodes

AbstractNeutral zinc‐air batteries are considered potential wearable energy storage devices due to their high theoretical energy density, superior safety, and low cost. However, the current performance of neutral zinc‐air batteries is severely influenced by the zinc anodes. The pure zinc anode can be comminuted during charge and discharge cycles due to its unstable electrode structure, resulting in the failure of electrical contact. As a result, the battery exhibits low capacity and short cycle life. In addition, the pure zinc anodes show slow reaction kinetics in neutral electrolytes, which causes the battery to perform low power density and poor energy efficiency. Besides, pure zinc anodes own high bending stiffness, which cannot meet the demands for powering flexible electronics. Herein, a new kind of hybrid zinc/carbon nanotube fiber anode with a stable electrode structure, high reaction activity, as well as high flexibility is proposed to produce high‐performance neutral zinc‐air batteries. The fabricated fiber battery showed a high specific capacity and maximum power density of 645.3 mAh g−1 and 615.8 mW g−1, respectively. Furthermore, a high energy efficiency of 71% is achieved, the highest among the reported neutral zinc‐air batteries. The entire fiber battery is highly flexible, highlighting its potential for wearable energy storage applications.

Constructing globally consecutive 3D conductive network using P-doped biochar cotton fiber for superior performance of silicon-based anodes

The inferior conductivity and drastic volume expansion of silicon still remain the bottleneck in achieving high energy density Lithium-ion Batteries (LIBs). The design of the three-dimensional structure of electrodes by compositing silicon and carbon materials has been employed to tackle the above challenges, however, the exorbitant costs and the uncertainty of the conductive structure persist, leaving ample room for improvement. Herein, silicon nanoparticles were innovatively composited with eco-friendly biochar sourced from cotton to fabricate a 3D globally consecutive conductive network. The network serves a dual purpose: enhancing overall electrode conductivity and serving as a scaffold to maintain electrode integrity. The conductivity of the network was further augmented by introducing P-doping at the optimum doping temperature of 350 °C. Unlike the local conductive sites formed by the mere mixing of silicon and conductive agents, the consecutive network can affirm the improvement of the conductivity at a macro level. Moreover, first-principle calculations further validated that the rapid diffusion of Li+ is attributed to the tailored electronic microstructure and charge rearrangement of the fiber. The prepared consecutive conductive Si@P-doped carbonized cotton fiber anode outperforms the inconsecutive Si@Graphite anode in both cycling performance (capacity retention of 1777.15 mAh g–1 vs. 682.56 mAh g–1 after 150 cycles at 0.3 C) and rate performance (1244.24 mAh g–1 vs. 370.28 mAh g–1 at 2.0 C). The findings of this study may open up new avenues for the development of globally interconnected conductive networks in Si-based anodes, thereby enabling the fabrication of high-performance LIBs.

Study on the Construction of Interlayer Adjustable C@MoS2 Fiber Anode by Biomass Confining and its Lithium/Sodium Storage Mechanism.

Building a stable and controllable interlayer structure is the key to improving the sodium storage cycling stability and rate performance of two-dimensional anode materials. This study explored the rich functional groups in bacterial cellulose culture medium in the way of biological self-assembly. Mo precursors were used to produce chemical bond in bacterial cellulose culture medium, and intercalation groups are introduced to achieve MoS2 localized nucleation and in situ localized construction of carbon intercalation stable interlaminar structure, thus improving ion transport dynamics and cycle stability. In order to avoid structural irreversibility of MoS2 at low potential, an extended voltage window of 1.5-4 V was selected for lithium/sodium intercalation testing. It was found that there was a significant improvement in sodium storage capacity and stability. During the electrochemical cycling process, in-situ Raman testing revealed that the structure of MoS2 was completely reversible, and the intensity changes of MoS2 characteristic peaks showed in-plane vibration without involving interlayer bonding fracture. Moreover, after the lithium sodium was removed from the intercalation C@MoS2 all structures have good retention.

Degradation of the Three-Phase Boundary Zone of Carbon Fiber Anodes in an Electrochemical System.

The electrochemical recycling nanoarchitectonics of graphene oxide from carbon fiber reinforced polymers (CFRPs) is a promising approach due to its economic and environmental benefits. However, the rapid degradation of the CFRP anode during the recycling process reduces its overall efficiency. Although previous studies have investigated the electrochemical oxidation of carbon fibers (CFs) and bonding of CFs to the matrix, few researchers have explicitly studied the electrochemical activity of CFs and the possible fracture caused by strong electrochemical reactions. To address this gap, this study investigates the degradation mechanism of CF anodes by analyzing changes in overall mechanical properties, hardness, elastic modulus, functional groups, and elemental composition of individual fibers. The experimental results demonstrate that the three-phase boundary region experiences the most severe degradation, primarily due to the number of oxygen-containing functional groups, which is the most important factor affecting the degree of degradation. This continuous decrease in the hardness and elastic modulus of individual fibers eventually leads to the fracture of CF anodes.

Investigating the Activity of Carbon Fiber Electrode for Electricity Generation from Waste Potatoes in a Single-Chambered Microbial Fuel Cell

Microbial fuel cells (MFCs), a technology that converts chemical energy into electrical energy, have been regarded as the most suitable method for sustainable energy production. However, most MFCs generate a low power output, limiting their large-scale industrial applications. Here, we introduce a high-performancesingle-chambered microbial fuel cell (SCMFC) based on carbon fiber anode and zinc oxide nanoparticle (ZnO NP)-fabricated copper cathode. Furthermore, best optimized conditions of temperature, pH, substrate, external resistance, and cathode fabrication were also considered to evaluate the performance of this SCMFC in treating potato wastewater along with bioenergy production. Results indicated that chemical oxygen demand (COD) could be effectively removed (80%) and maximum voltage, current density, and power density were 1.58 V, 0.235 mA/cm2, and 0.3714 mW/cm2, respectively. Hence, the SCMFC used in this study has a higher potential to treat potato wastewater along with high power production.