Search Results (365)

A flexible integrated composite electrode is fabricated using NiV-layered double hydroxide (NiV-LDH) nanosheets grown perpendicularly onto a Ti₃C₂T_x MXene-incorporated carbon nanofiber scaffold (MXene/CNFs). This hybrid structure, prepared by electrospinning and a hydrothermal treatment, is referred to as NiV-LDH@MXene/CNFs. Constructed from a conductive MXene/CNF scaffold and vertically aligned NiV-LDH nanosheets, the integrated flexible electrode offers uninterrupted electron transport, good flexibility, abundant active sites, and strong interfacial cohesion, thereby obviating the use of polymeric binders and conductive additives. The hydrophilic nature of MXene and the three-dimensionally interconnected porous structure favor rapid electrolyte uptake and ion diffusion. As a result of these synergistic effects, the composite exhibits a specific capacitance of 614 F g⁻¹ at 1 A g⁻¹ and retains 60% of its initial capacitance after 10,000 cycles at 5 A g⁻¹ in a three-electrode cell. An asymmetric supercapacitor made of this material and activated carbon achieves 68.75% capacitance retention under the same cycling protocol at 5 A g⁻¹ and shows a stable open-circuit voltage of 1.37 V. Two cells in series are capable of lighting a 3 V LED strip. Overall, this work validates an effective strategy to prepare high-capacity, robust, and binder-free flexible electrodes for advanced energy-storage applications. Full article

The corrosion-protection performance of zinc oxide-hybrid polymeric coatings is traditionally attributed to the individual contributions of their constituent phases. This study reveals that the calcination temperature of zinc oxide (ZnO) filler is a critical, previously overlooked processing parameter that dictates not only filler crystallinity but also the collective synergistic failure mechanism of the entire coating system. Herein, we demonstrate that incorporating ZnO calcined at 500 °C yields a ternary chitosan–graphene oxide–zinc oxide/epoxy (CS–GO–ZnO/EP) composite coating with a highly compact, dense morphology, minimal internal porosity, and exceptional filler dispersion, as validated by FTIR, XRD, and SEM analyses. The optimized CS–GO–ZnO/EP coating applied to carbon steel exhibits outstanding dry and wet pull-off adhesion strengths, the highest surface hydrophobicity (102.2°), and superior electrochemical barrier protection. Notably, after a 120-h immersion period in an aggressive 3.5 wt.% NaCl electrolyte, the CS–GO–ZnO/EP (500 °C) maintains excellent coating resistance (R_coat = 1.06 × 10⁵ Ω) and a minimized corrosion rate (CR = 0.074 mm/y). This thermal threshold is a key processing window that improves chemical bonding and compatibility between the different parts of the hybrid matrix without causing the severe nanoparticle sintering, phase aggregation, and micro-cracking that happen at 650 °C. This work offers a significant advancement in the design of eco-friendly, high-performance hybrid coatings, demonstrating that precise control of the inorganic phase’s thermal history provides a direct pathway toward superior durability, hydrophobicity, and electrochemical stability for carbon steel protection in aggressive marine environments. Full article

The electrolytic composition plays an important role in the structure and corrosion protection performance of electro-polymerized coating. In the present work, oxalic acid, hydrochloric acid, sulfuric acid, phosphoric acid and benzoic acid were utilized as electrodeposition electrolytes to prepare a PANI coating. The PANI coating deposited in benzoic acid showed a compact and uniform structure with an adhesion grade of 0. Electrochemical tests revealed that the benzoic acid-doped PANI coating exhibited the smallest value of corrosion current density of 2.571 μA·cm⁻² and the largest inhibition efficiency of 92.6% among the investigated acidic electrolytes. Moreover, the influence of co-electrodeposition conditions, including cerium nitrate concentration, ammonium acetate concentration and electrolyte pH value on the corrosion protection performance of co-electrodeposited PANI/CeO₂ was investigated and the optimal co-electrodeposition condition was found to be 0.3 mol/L aniline, 0.04 mol/L benzoic acid, 0.10 mol/L cerium nitrate, 0.10 mol/L ammonium acetate and pH of 5.5, under which condition the corrosion current density was decreased to 0.199 μA·cm⁻² and the inhibition efficiency reached 99.4%. Full article

The evolution of electronic technology has intensified the demand for lithium-ion batteries to achieve elevated energy density, prolonged cycling longevity, and enhanced safety. Traditional graphite anodes are inadequate in meeting these requirements. α-Fe₂O₃ possesses a high theoretical capacity and is abundantly available; however, its poor conductivity and significant volume expansion during charge–discharge cycles restrict its practical applicability. This study addresses these issues by developing a three-layer cooperative structural anode material composed of foam nickel (NF), α-Fe₂O₃, and polypyrrole (PPY). Employing a hydrothermal method, α-Fe₂O₃ nanowires were in-situ grown on the 3D framework of foam nickel, followed by electro-polymerization to achieve a dense PPY coating. The foam nickel offers a highly conductive scaffold and mechanical support, while PPY enhances conductivity, provides structural buffering, and facilitates in-situ nitrogen doping. Collectively, these components synergistically improve conductivity, mitigate volume expansion, and optimize the solid electrolyte interphase. This composite material demonstrates comprehensive enhancements in conductivity, structural stability, and interface compatibility, as evidenced by the well-preserved structural integrity after prolonged cycling, thereby overcoming the performance limitations associated with singular α-Fe₂O₃ and simplistic composite systems, and presenting novel insights and technical support for the advancement of high-energy-density lithium-ion battery anodes. Full article

Constructing core–shell structured carbon-coated alloy nanoparticles represents an effective strategy to enhance the electrocatalytic performance. In this work, CoFe-based Prussian blue analogs (PBAs) with hollow structures are firstly coated with phenolic resin via the in situ polymerization method. A subsequent carbonization treatment yields N-doped carbon-encapsulated CoFe alloy nanocubes (denoted as CoFe-NC@C). The carbon shell suppresses the structural collapse and particle aggregation of CoFe nanocubes while enhancing the electrical conductivity, thereby facilitating fast reaction kinetics. Meanwhile, the etching-induced hierarchical pore structure increases the specific surface area with a Brunauer–Emmett–Teller (BET) value of 57 m² g⁻¹, which exposes more accessible active sites and facilitates mass transport. Owing to the synergistic effect between the two components, the CoFe-NC@C catalyst exhibits an outstanding oxygen evolution reaction (OER) performance in an alkaline electrolyte, achieving a low overpotential of 278 mV (vs. RHE) at a current density of 10 mA cm⁻² along with superb durability. This work demonstrates that the OER performance of PBA-derived alloys can be boosted through an integrated strategy of etching and carbon coating. Full article

The dewatering of cyanobacteria-laden sludge remains a challenge. Extracellular polymeric substances (EPS) mainly consist of polysaccharides and proteins, which form a stable gel network with water through hydrogen bonding and other interactions. To address this bottleneck, a low-voltage (5 V) electrochlorination system was constructed, employing a Ti/IrO₂/RuO₂ electrode as the anode, iron as the cathode, and calcium chloride dihydrate (CaCl₂·2H₂O) as the electrolyte. The results showed that the active chlorine generated during electrolysis degraded the highly water-retentive loosely bound EPS (LB-EPS) and tightly bound EPS (TB-EPS), converting them into low-viscosity, easily removable soluble EPS (S-EPS). Moreover, the total contents of polysaccharides and proteins in EPS decreased. Three-dimensional excitation-emission matrix fluorescence spectroscopy revealed that in the EPS of the algal sludge, the relative proportion of humic-like substances increased, while that of protein-like products decreased. At a CaCl₂·2H₂O dosage of 1 g/L, the dewatering performance of the algal sludge was significantly improved: the capillary suction time (CST) of the algal suspension decreased from 10.30 ± 0.1 s to 4.1 ± 0.05 s, the proportion of bound water decreased from 43.5% to 9.8%, and the cake solids content increased to 9.48%. The residual water quality of this process was also favorable, with total phosphorus (TP) and total nitrogen (TN) concentrations stabilized at 0.166 ± 0.040 mg/L and 9.0 ± 1.1 mg/L, respectively. Therefore, this study provides an efficient, low-energy electrochemical pretreatment strategy to overcome the dewatering bottleneck in cyanobacteria-laden sludge, thereby reducing the treatment load and cost of downstream mechanical dewatering. Full article

The introduction of a quantitative definition of fish freshness enables the determination of the remaining storage time of raw fish materials. To measure this value, a virtual array of electrochemical chemotransistor-based chemical sensors was developed. The electrolyte used to electrically connect the four measurement electrodes and the reference electrode was optimized. To achieve the high stability, high electrochemical activity of chemosensitive material, and reversible potential of the silver/silver chloride reference electrode, a chloride-containing ionic liquid and polymeric acid mixture was used as the electrolyte. Polyaniline in different redox states was applied as the chemosensitive material with electrically controlled affinity. First, the sensor was evaluated for trimethylammonium detection, and then it was applied to fish samples. Unlike the response observed for trimethylammonium, the sensor’s response to fish samples exhibited complex, non-exponential kinetics and a non-monotonic dependence on the storage duration of fish samples. To characterize these responses, a set of descriptors was introduced. The storage time was estimated by minimizing the Euclidean distance between the descriptors values obtained from fish samples and those determined during calibration. Based on the quantitative definition of freshness, this approach categorizes the current stage of fish products and predicts the remaining storage duration quantitatively. Full article

Actin cytoskeleton is a fundamental cellular structure governing stress signal transduction and cellular homeostasis in plants. While its involvement in heat stress adaptation has been documented, the transcriptional and cytoskeletal regulatory networks underlying rice thermotolerance remain poorly defined. Here, we report that the actin-depolymerizing factor OsADF7 acts as a negative regulator of rice heat acclimation through modulating microfilament dynamics, and is transcriptionally controlled by the R2R3-MYB transcription factor OsMYB30. Heat stress markedly suppresses the expression of both OsMYB30 and OsADF7. Functional characterization demonstrated that knockout of Osadf significantly enhances heat acclimation by preserving microfilament polymerization, whereas overexpression (OE) of OsADF7 confers heat acclimation in rice seedlings. Physiological analyses including survival rate, electrolyte leakage, MDA, ROS, chlorophyll content and Fv/Fm further validated the heat acclimation phenotypes. Mechanistically, OsMYB30 directly binds to the TATCC cis-element in the OsADF7 promoter and may positively regulate OsADF7 transcription. Consequently, knockout of Osmyb30 enhances heat tolerance, while OE of OsMYB30 induces OsADF7 expression and leads to heat hypersensitivity. Genetic epistasis analyses support that the OsMYB30-OsADF7 transcriptional module may serve as a potential regulatory module involved in actin cytoskeleton-associated heat acclimation in rice. Collectively, our findings provide preliminary mechanistic clues linking MYB-related transcriptional regulation to actin cytoskeletal dynamics during rice thermotolerance responses, and provide a promising target for genetic improvement of heat-resistant rice varieties. Full article

This study proposed an effective capacitance (C_ec) for bare and conducting polymer-covered electrodes using electrochemical impedance spectroscopy (EIS). Bare electrodes show three regimes: potential-dependent Helmholtz capacitance, Gouy–Chapman–Stern diffusion capacitance (1 MHz–10 Hz), and complex low-frequency responses, deviating from semi-infinite Warburg diffusion (1 Hz–10 mHz). Polyaniline (PANI) and poly(3,4-ethylenedioxythiophene) PEDOT-based electrodes exhibit larger potential-dependent diffusion pseudocapacitance (1 MHz–10 Hz) and the absence of a Warburg tail or a nearly horizontal low-frequency slope at 0.01–0.026 (1 Hz–10 mHz). A high-frequency C_ec of a PANI membrane correlates with bulk electrolyte concentration, while bare electrodes are less affected and dominated by Helmholtz capacitance. The equivalent circuit of the time-dependent EIS impedance spectrum for bare electrodes and PANI and PEDOT-based electrodes shows parallel capacitor behavior in combination with high-frequency capacitance (1 MHz–10 Hz) and a low-frequency response (1 Hz–10 mHz). The mathematical simulation of effective capacitance C_ec with respect to time period t (f⁻¹) follows two time constants (τ = RC), representing double-layer capacitance or pseudocapacitance (τ₁) and complex low-frequency responses or Warburg diffusion (τ₂) for bare electrodes and conducting polymer-based electrodes, respectively. This simulation analysis also elucidates the frequency dependence of the Warburg characteristic frequency (ω) and the extension of the double-layer capacitance diffuse distance L_D for H⁺ with GC electrodes to approximately 7.37–15.15 μm over a time interval of ca. 1 s (t = f⁻¹). The diffusion coefficient D_i of K⁺ ion transfer through a PEDOT solid contact from 1 mC (0.1 µm) to 10 mC (1 µm) is in the range of 0.57–12 × 10⁻¹⁰ cm²·s⁻¹, following a power law with an exponent of 1.75 with respect to the polymerization time of PEDOT, which is inconsistent with Fick’s law. Full article

Limited ionic conductivity and unstable interfaces, primarily caused by poor solid–solid contact, pose significant challenges to the stable cycling of solid-state batteries. In this study, an interfacial in situ polymerization strategy is proposed to construct a poly(1,3-dioxolane) (PDOL) gel electrolyte layer between a poly(vinylidene fluoride) (PVDF)-based solid polymer electrolyte and the electrodes. This approach aims to address interfacial compatibility issues in solid-state lithium metal batteries. By precisely tuning the composition of the gel precursor and employing characterization techniques such as FTIR and NMR, the efficient ring-opening polymerization of 1,3-dioxolane (DOL) was confirmed, achieving a high conversion rate of 90%. The precursor was drop-cast onto the PVDF-based electrolyte/electrode interfaces before cell assembly. Electrochemical evaluations revealed that the in situ formed solidified interlayer significantly enhanced interfacial compatibility and ion transport, yielding a high Li⁺ transference number (0.341), an exceptional critical current density (1.4 mA cm⁻²), and remarkable cycling stability exceeding 1600 h in Li||Li symmetric cells. Furthermore, full cells incorporating LiFePO₄ cathodes demonstrated excellent rate capability and long-term cyclability, retaining 98.7% of their capacity after 1000 cycles. These results collectively underscore the effectiveness of this in situ solidification strategy in optimizing the interface structure and improving the overall performance of PVDF-based solid-state batteries. Full article

A polymer electrolyte is developed by integrating a poly(methyl methacrylate) (PMMA)/eutectic electrolyte (EE) phase into a porous polyethylene (PE) scaffold via a solution-casting strategy. In this rigid–flexible coupled architecture, the PMMA matrix serves as a solid host that coordinates with Li⁺ through its polar carbonyl groups, thereby promoting lithium salt dissociation and establishing a stable ion transport network. The incorporated EE, composed of ethylene carbonate and LiTFSI, effectively reduces the glassy rigidity of PMMA and provides continuous pathways for fast ionic conduction. Meanwhile, the porous PE scaffold reinforces mechanical strength and resists lithium dendrite penetration, enabling a thin electrolyte membrane with excellent flexibility. The resulting electrolyte achieves an ionic conductivity of 1.59 × 10⁻⁴ S cm⁻¹ at 30 °C, a lithium-ion transference number of 0.45, and an electrochemical stability window up to 4.75 V. In Li||LiFePO₄ cells, it delivers stable cycling at 3 C for 1000 cycles with 76.8% capacity retention and a Coulombic efficiency exceeding 99.9%. The monomer-free design eliminates residual reactive species that commonly compromise interfacial stability, offering a reliable pathway toward high-voltage solid-state lithium-metal batteries. Full article

As the global demand for lithium-ion batteries (LIBs) continues to rise, battery recycling has become a critical strategy for mitigating resource depletion, minimising environmental impact, and advancing a circular economy. However, recycled electrode materials, particularly cathode and anode powders, often contain residual impurities such as transition metals (e.g., Cu, Fe, Al), polymeric binders (e.g., PVDF), and electrolyte decomposition products. These contaminants can significantly impair the electrochemical performance, thermal stability, and overall safety of newly manufactured cells. This study aims to systematically investigate the nature, origin, and impact of impurities in recycled cathode and anode materials. A suite of analytical techniques, including inductively coupled plasma mass spectrometry (ICP-MS), infrared spectroscopy (IR), scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS), and thermogravimetric analysis (TGA), will be employed to quantify impurity levels and assess material integrity across various recycling streams. The findings are expected to inform the establishment of impurity threshold limits for battery-grade recycled materials and guide the development of enhanced purification protocols. Ultimately, this research will support the production of safer and more reliable second-life batteries, offering valuable insights to recyclers, manufacturers, and regulatory bodies committed to sustainable energy storage technologies. Full article

Perylene bisimide derivatives are typical n-type semiconductors as well as redox-active materials. However, it has been difficult to produce thin films by solution processes because of their low solubilities in organic solvents. Perylene bisimide derivatives bearing oligosiloxane moieties exhibit columnar phases over wide temperature ranges, including room temperature and high solubilities in organic solvents. The columnar phases are stabilized by nanosegregation between crystal-like one-dimensional π-stacks and liquid-like mantle consisting of oligosiloxane moieties. The electron mobility at room temperature exceeded 0.1 cm²V⁻¹s⁻¹ in the ordered columnar phases of perylene bisimide derivatives bearing four disiloxane chains. Uniaxially aligned thin films of the perylene bisimide derivatives bearing oligosiloxane moieties could be produced by a spin-coating method. The spin-coated films of the perylene bisimide derivatives bearing cyclotetrasiloxane rings could be insolubilized via in situ ring-opening polymerization by the exposure of the thin films to trifluoromethanesulfonic acid vapors. Uniaxially aligned thin films of perylene bisimide derivatives bearing an ethylene oxide chain as well as cyclotetrasiloxane rings could be doped in an aqueous solution of sodium dithionate, resulting in an anisotropic electrical conductivity. Polymerized thin films of perylene bisimide derivatives bearing a crown ether ring exhibited electrochromism in electrolyte solutions. These compounds formed 1:1 complexes with lithium triflate, exhibiting columnar phases at room temperature. The nanostructures of the complexes were stabilized by the electrostatic interaction between cationic crown-metal units and triflate anions. Full article

Nd₂NiO_4+δ was investigated as a Ruddlesden–Popper (RP) cathode material for intermediate-temperature solid oxide fuel cells (IT-SOFCs), with particular emphasis on its electrochemical performance and oxygen reduction reaction mechanism. The material was synthesized via a polymeric sol–gel route derived from Pechini’s method and evaluated in symmetric cells using Ce_0.9Gd_0.1O_2−δ (GDC) as the electrolyte. X-ray diffraction confirmed the formation of a single RP phase and good chemical compatibility with GDC after thermal treatments at 800 °C. Cathode layers with thicknesses of 8–12 µm were deposited by dip-coating. Electrical conductivity measurements revealed a thermally activated semiconducting behavior governed by Ni²⁺/Ni³⁺ small-polaron hopping, with an activation energy of ~1.08 eV. Electrochemical impedance spectroscopy showed a strong temperature dependence of the area-specific resistance, decreasing from 9.18 Ω·cm² at 600 °C to 0.39 Ω·cm² at 800 °C. Distribution of relaxation times (DRT) analysis enabled the identification of the dominant electrochemical processes, indicating that oxygen surface exchange reactions are more favorable than charge transfer at the cathode–electrolyte interface, which remains the main limiting step. These results demonstrate that Nd₂NiO_4+δ is a promising cathode for IT-SOFC operation, while further optimization of the electrode–electrolyte interface is required to enhance its oxygen reduction kinetics. Full article

Hazardous compounds from used batteries pose a great threat to the environment. To prevent pollution and to recover critical materials from battery waste, efficient recycling is required. Until now, battery recycling has focused on the recovery of valuable metals from cathode materials, while organic fractions have often been neglected due to their low material value. New approaches to battery recycling are therefore necessary, where recycling methods based on supercritical carbon dioxide (SC-CO₂) extraction show great potential. In this work, a SC-CO₂ method was implemented to extract electrolyte solvents for the purification and recovery of a separator waste material (SWM) sorted out from lithium-ion battery (LIB)-based black mass. In addition, two other separation routes (ultrasonic washing and thermal treatment) were used for comparison. Based on the results from the three routes, mass balances revealed the gravimetric composition of the SWM, which includes separator, electrolyte, and electrode powder. The composition of electrolyte solvents was determined via Gas Chromatography-Mass Spectroscopy analysis. Furthermore, the polymeric separator was analyzed using Fourier Transform Infrared Spectroscopy, Thermogravimetric Analysis, and Differential Scanning Calorimetry analysis to evaluate the effects of SC-CO₂ extraction on the physicochemical properties. The recovery of electrolyte by the SC-CO₂ route is more efficient than the others, with extraction yields of 162 mg of electrolyte per gram of SWM. Moreover, no changes are observed in the analyzed properties of the polymeric separator material due to the SC-CO₂ extraction. Thus, the SC-CO₂ process proves to be a promising method for an efficient and sustainable recycling of electrolyte solvent and purifying of separator material from LIB waste. Full article