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The current collector, one of the main components in the manufacture of composite electrodes, is mainly used to enhance the mechanical stability and improve the performance and cycle performance of the electrodes. During the electrochemical reaction, the lithium diffusion can induce compressive stress and affect the mechanical performance, lifespan, and performance of batteries. Therefore, this study analyzed the influence of copper foil on the mechanical response and degradation performance of electrodes. In addition, a mathematical model was developed to analyze the effect of copper foil on the stress–strain behavior of the electrodes. The results indicated that the stress and modulus of the graphite electrodes have a non-linear increase with the lithiation process. Based on those findings, utilizing a thinner and more compliant current collector could effectively mitigate the in-plane strain and the stress within electrodes. Thus, developing a thinner and softer copper foil could simultaneously enhance the mechanical properties and specific density of composite electrodes for the next-generation LiBs. [ABSTRACT FROM AUTHOR]

Electrochemical Double Layer Capacitors (EDLCs) with ionic liquid electrolytes outperform conventional ones using aqueous and organic electrolytes in energy density and safety. However, understanding the electrochemical behaviors of ionic liquid electrolytes under compressive/tensile strain is essential for the design of flexible EDLCs as well as normal EDLCs, which are subject to external forces during assembly. Despite many experimental studies, the compression/stretching effects on the performance of ionic liquid EDLCs remain inconclusive and controversial. In addition, there is hardly any evidence of prior theoretical work done in this area, which makes the literature on this topic scarce. Herein, for the first time, we developed an atomistic model to study the processes underlying the electrochemical behaviors of ionic liquids in an EDLC under strain. Constant potential non-equilibrium molecular dynamics simulations are conducted for EMIM BF4 placed between two graphene walls as electrodes. Compared to zero strain, low compression of the EDLC resulted in compromised performance as the electrode charge density dropped by 29%, and the performance reduction deteriorated significantly with a further increase in compression. In contrast, stretching is found to enhance the performance by increasing the charge storage in the electrodes by 7%. The performance changes with compression and stretching are due to changes in the double-layer structure. In addition, an increase in the value of the applied potential during the application of strain leads to capacity retention with compression revealed by the newly performed simulations. [ABSTRACT FROM AUTHOR]

Hybrid capacitive deionization (HCDI) emerges as a burgeoning electrochemical desalination technology due to the utilization of profitable pseudocapacitive reactions. Although tunable organic compounds are potential faradaic electrode materials, their insufficient active sites and high water‐solubility restrict practical HCDI applications. Herein, a pseudocapacitive organic polymer (PNDS) is proposed with diverse redox‐active sites for electrochemical deionization. The pronounced molecular aromaticity and strong π‐electron delocalization not only endow PNDS polymer with framework rigidity, but refine its electronic structure to bolster redox activity and electron affinity. As an electrode material, the PNDS polymer demonstrates a substantial pseudocapacitive capacitance of 390 F g−1 and sustains long‐term stability at 96.3% after 5000 cycles, surpassing reported Na+‐capturing organic electrodes. In‐operando monitoring techniques and theoretical calculations reveal efficient Na+ capture at the C═N and C═O redox‐active sites within the PNDS electrode during repeated electrosorption processes. As a conceptual demonstration, a high‐performance HCDI device equipped with the PNDS electrode exhibits an impressive salt removal capacity (66.4 mg g−1), a rapid removal rate (2.2 mg g−1 min−1) and stable regeneration property. More importantly, an integrated desalination system is engineered to rapidly and repeatedly treat saltwater resources for human consumption and agricultural irrigation, highlighting its promising prospects for high‐efficiency desalination applications. [ABSTRACT FROM AUTHOR]

Designing potential architectures by the modification of conventional electrode materials is an effective approach in the development of high performance supercapacitor electrodes. The present study investigated the effect of varying anodization voltages (50, 75, and 100 V) on the morphology and electrochemical properties of titanium nanotubes (TNT). Molybdenum was doped onto TNT using a simple hydrothermal procedure, followed by thermal treatment at 450 °C. The study effectively demonstrated control over the dimensions of the nanotube structure by adjusting the anodization voltage. Additionally, it was found that the tube diameters were increased due to etching during the hydrothermal treatment with the Mo precursor, which potentially enhanced the supercapacitive performance of Mo‐doped TNT. Further, structural analysis revealed that Mo doping improved both crystallinity and electrode stability. With an optimal anodization voltage of 100 V, TNT and Molybdenum‐doped TNT could exhibit capacitance value of 13.34 and 326.54 mF cm−2 respectively, at a current density of 1 mA cm−2. Furthermore, the electrode demonstrated good cyclic stability with 88% capacitance retention and 97% coulombic efficiency after 5000 cycles. An impressive energy density of 87.03 µWh cm−2 and a power density of 799.99 µW cm−2 could be achieved with this sample in an asymmetrical device. [ABSTRACT FROM AUTHOR]

In order to solve the problem of low energy density of previous cement-based supercapacitors, the capacitor performance was optimized in four aspects: positive electrode performance, positive and negative capacity matching, and electrolyte performance. The effects of electrodeposition solution ratio and scan rate on the electrochemical properties of nickel–cobalt double hydroxide were investigated. The microscopic morphology and elements of nickel–cobalt double hydroxide were analyzed by scanning electron microscopy (SEM), Fourier transform infrared (FTIR), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The optimized nickel–cobalt double hydroxide electrode demonstrates an excellent areal capacitance of 10.53 F cm−2 and excellent cycling stability (106% capacitance retention after 10 000 cycles) at a current density of 1 mA cm−2. In this paper, an electrode made of activated carbon was used as the negative electrode and the loading of activated carbon was strictly controlled to better match the high specific capacitance of the nickel–cobalt double hydroxide electrode. An optimally proportioned cementitious-polymer electrolyte was selected as the electrolyte for the supercapacitor. The three-step optimized supercapacitor exhibits a high areal capacitance of 1.442 F cm−2, good cycle retention (69.4%), and a remarkable energy density of 0.444 mW h cm−2 (0.75 mW cm−2). This paper is expected to provide a new way to mitigate the issue of "curtailed light" and to construct large-scale buildings integrating light, electricity, and energy storage. [ABSTRACT FROM AUTHOR]

Solid‐state lithium batteries (SSLBs) offer inherent safety and high energy density for next‐generation energy storage, but the large interfacial resistance and poor physical connection between electrode materials and the solid electrolyte (SE) severely impede their practical applications. This work reports a general strategy to introduce covalent bonds between electrode materials and SE, not only reducing interfacial resistance but also enhancing electrochemical stability and mechanical robustness of SSLBs. The covalent bonding is accomplished by functionalizing electrode surfaces with C═C groups, enabling in situ copolymerization with telechelic polymers in the SE. This approach is applicable to various cathode/anode materials and SEs. Particularly, the SSLBs comprising LiFePO4 cathode, Li6.75La3Zr1.75Ta0.25O12/(polyethylene oxide (PEO)/lithium bis(trifluoromethylsulfonyl)imide (LiTFSI)/silk composite SE and metallic lithium anode exhibit a specific capacity of 158.4 mAh g−1 and can be cycled at 2 C for 2200 times with >80% retention. Additionally, the SSLBs containing the high nickel‐content LiNi0.96Co0.03Mn0.01O2 cathode can afford a high specific capacity of 201.8 mAh g−1. Comprehensive experimental examination and theoretical simulations confirm that the lowered interfacial resistance and intimately contacted electrode materials/electrolyte interfaces facilitate Li+ transport at different stages of charge. Furthermore, the covalently bonded electrode/electrolyte interfaces also endow SSLBs with outstanding mechanical stability, enabling flexible SSLB pouch cells to operate under various bending states without performance decay. [ABSTRACT FROM AUTHOR]

The design of electrochemical sensors is crucial considering important factors such as efficiency, low cost, biocompatibility, and availability. Manganese oxides are readily available, low-cost, and biocompatible materials, but their low conductivity limits their efficiency as sensors. Today, morphology engineering of manganese oxide has been one of the most common research topics, because manganese oxides' electrochemical properties are highly dependent on their morphologies. In this study, a method for reducing the charge transfer resistance (Rct) of MnO2-based electrodes was established by the cyclic voltammetry technique accompanied by step-by-step heat treatment to electrodeposition MnO2 nanofilm, which remarkably improved the Rct. Next, the sensing performance of MnO2/FTO for two separate measurements was examined, one for the simultaneous measurement of paracetamol (PAR) and 4-aminophenol (4-APh), and the other for the measurement of 4-nitrophenol (4-NP). Under the optimum conditions, the linear ranges of 4-APh, PAR, and 4-NP, were 0.8 to 22.0 µM, 2.0 to 55.0 µM, and 0.1–250 µM, with limits of detection (LOD) of 0.19 µM, 0.60 µM, and 0.01 µM, respectively. It also was unaffected by a 200-fold excess of interferences. In addition, the designed sensor was successfully applied to the analysis of real samples. [ABSTRACT FROM AUTHOR]

Electrochemical energy storage devices with high specific capacity are of utmost important for the next-generation electronic devices. Supercapatteries (SCs) are highly demanded energy storage devices nowadays as these bridge the low energy supercapacitors and low power batteries. Herein, we report a rapid synthesis of cobalt manganese phosphate (COMAP) by microwave-assisted hydrothermal method and facile fabrication of SCs using electrodes comprising of COMAP as positrode material. The effect of precursor concentration on the microstructure and surface morphology of the COMAP samples are examined initially. Further, the electrochemical performance of COMAP electrodes is studied systematically in 3 M KOH (aqueous) electrolyte. COMAP exhibits excellent charge storage capabilities where type of charge storage mechanism is found to be battery-type based on the calculation obtained from Dunn's method. The SC electrode fabricated with COMAP synthesized using cobalt: manganese precursor ratio as 80:20 exhibits a highest specific capacity of 191.4 C/g at a scan rate of 1 mV/s. An asymmetric SC (ASC) cell fabricated with COMAP as positrode and activated carbon (AC) as negatrode exhibits a specific capacity of 165.5 C/g at a current density of 1.8 A/g. The COMAP//AC ASC cell exhibits an energy density of 34.1 Wh/kg at a corresponding power density of 1875 W/kg at a current density of 1.8 A/g. [ABSTRACT FROM AUTHOR]

Hydrogen is a renewable and environmentally friendly energy carrier and is considered a viable alternative to fossil fuels. Consequently, developing electrodes with excellent hydrogen evolution electrocatalysis is a top priority in research. However, the use of flat electrodes as cathode substrates by most researchers limits the electrocatalytic active area of the prepared electrode. To address this issue, it is essential to prepare a micro-nano structure on a cathode substrate before electrodeposition. This study introduced a novel Ni nanocone/Grid electrode, obtained through a combined laser-electrodeposition process to investigate its electrocatalytic activity and stability for the hydrogen evolution reaction (HER). Various techniques, including linear sweep voltammetry (LSV), electrochemical impedance spectra (EIS), cyclic voltammetry (CV), and chronopotentiometry (CP) in 1 M KOH solution, were employed to assess the HER electrocatalytic performance of the Ni nanocone/Grid electrodes. The experimental results demonstrated that the electrodes could achieve current densities of -10, -20, and -100 mA/cm2 with corresponding overpotentials of -281, -308, and -390 mV, respectively. Additionally, the Tafel slope of these electrodes was found to be only -82.05 mV/dec. The enhanced catalytic performance of the electrode was attributed to the synergistic effect of the grid-like and nanocone structures, which significantly increased the electrocatalytically active area and improved surface hydrophilicity, thereby boosting electrocatalytic performance. The simplicity of the preparation method and the exceptional performance of the electrode provide a promising new avenue for future research on HER electrocatalysts. • A new laser-electrodeposition combined process was proposed to prepare the catalytic electrode for hydrogen evolution. • Ni nanocone/Grid showed low overpotential and Tafel slope for hydrogen evolution. • The combination of grid structure and nanocone can significantly increase the ECSA of the electrode. • The electrode shows excellent hydrophilicity and extraordinary durability. [ABSTRACT FROM AUTHOR]

Metal organic frameworks (MOF's) have gained considerable attention in the field of energy storage and supercapacitors applications. Herein, we synthesized copper oxide (CuO) through the precipitation method and concurrently derived from the solvothermal prepared copper-benzene dicarboxylate (Cu-BDC) by calcination. The integration of MOF-derived nanostructures with traditional CuO to form a hybrid electrode material, has not been extensively explored. The synthesized materials were characterized using x-ray Diffractometry, FTIR, XPS, Brunauer, Emmett, and Teller and morphological analysis was conducted using scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (HRTEM) affirming the composite's nature. Electrochemical impedance spectroscopy, galvanostatic charge–discharge, and cyclic voltammetry were used to evaluate the electrochemical properties of electrode material. With a specific capacitance of 691 Fg−1 for CuO obtained from Cu-BDC (benzene dicarboxylic acid) and 236 Fg−1 for CuO via the precipitation method, measured at a scan rate of 5 m Vs−1 in 6 M KOH was found to be the optimal performance solution for the electrode material. The mesoporous structures are crucial for their absorption ability and improved ion transport, resulting in optimized electrochemical performance. Finally, we demonstrate significant improvements in specific capacitance and cycling stability compared to pure CuO-based electrodes, highlighting the potential of this composite structure for advanced supercapacitor applications. [ABSTRACT FROM AUTHOR]

Electrodes, which offer sites for mass transfer and redox reactions, play a crucial role in determining the energy efficiencies and power densities of redox flow batteries. This review focuses on various approaches to enhancing electrode performance, particularly the methods of surface etching and catalyst deposition, as well as some other advanced strategies for regulating electrode surface properties. These approaches aim to increase active sites and enhance kinetics for the redox reactions, which are crucial for elevating power density and electrolyte utilization, eventually determining the performance of the flow battery. Highlighting the need for interdisciplinary research, this mini‐review suggests that future advancements in electrode design will significantly impact the commercial viability and adoption of redox flow batteries in sustainable energy storage solutions. [ABSTRACT FROM AUTHOR]

Industrial applications of microbial electrochemical systems will require regular maintenance shutdowns, involving inspections and component replacements to extend the lifespan of the system. Here, we examined the impact of such shutdowns on the performance of three electrode materials (i. e., platinized titanium, graphite, and nickel) as cathodes in a microbial electrochemical system that would be used for electromethanogenesis in power‐to‐gas applications. We focused on methane (CH4) production from hydrogen (H2) and carbon dioxide (CO2) using Methanothermobacter thermautotrophicus. We showed that the platinized titanium cathode resulted in high volumetric CH4 production rates and Coulombic efficiencies. Using a graphite cathode would be more cost‐effective than using the platinized titanium cathode in microbial electrochemical systems, but showed an inferior performance. The microbial electrochemical system with the nickel cathode showed improvements compared to the graphite cathode. Additionally, this system with a nickel cathode demonstrated the fastest recovery during a shutdown experiment compared to the other two cathodes. Fluctuations in pH and nickel concentrations in the catholyte during power interruptions affected CH4 production recovery in the system with the nickel cathode. This research enhances understanding of the integration of biological and electrochemical processes in microbial electrochemical systems, providing insights into electrode selection and operating strategies for effective and sustainable CH4 production. [ABSTRACT FROM AUTHOR]

In the current study, we synthesized copper oxide nanostructures (CuO NSs) via a facile hydrothermal procedure. We characterized them with the help of scanning electron microscopy (SEM) and X-ray diffractometry (XRD). SEM study revealed that CuO NSs inherited nanoneedles-based flowering geometry with a porous nature, while XRD proved the crystalline nature of these NSs. When deposited on a glassy carbon electrode (GCE), these nanostructures are displayed as a sensitive sulfite detection tool in the sample matrix. The results showed that sodium hydroxide, with pH 10.0, was the best-supporting electrolyte among all electrolytes studied. The as-prepared sulfite sensor performed well in a linear working range of 10–100 µM sulfite with the low detection limit (LOD) of the amperometry technique used to evaluate the analytical performance of the electrode, such as a limit of 1.12 µM. The developed sensor was highly stable and reproducible, showing a relative standard deviation of 2.17% for 10 cycles. The sensor also exhibited more selectivity for sulfite in the presence of probable interfering species, including cyanide, sulfate, chloride, and nitrate. The findings further proved the CuO/GCE-Nafion-based sensor as a sensitive diagnostic tool for quantifying or monitoring health-hazardous sulfite in the environmental sample matrices. [ABSTRACT FROM AUTHOR]

Modern sensing technologies are highly required for health monitoring. In this respect, the development of small‐size, high‐performance, and self‐powered biosensors for detecting and quantifying disease markers in biofluids can bring crucial changes and improvements to the concept of health monitoring systems. Clinical trials identify a wide range of biomarkers in biofluids that provide significant health information. Research into novel functional materials with outstanding properties opens up new perspectives for fabricating new‐generation biosensors. Furthermore, energy conversion and storage units are investigated to integrate them into biosensors and develop self‐powered systems. Electrochemical methods are very attractive for applications in biosensor technology, both in terms of biomarker detection and energy generation. Here the recent achievements in research into self‐powered electrochemical biosensors to detect sweat and saliva biomarkers are presented. Potential biomarkers for efficient analysis of these fluids are discussed in light of their importance in identifying various diseases. The influence of electrode materials on the performance of sensors is discussed. Progress in developing operating strategies for self‐powered electrochemical monitoring systems is also discussed. A summary and outlook are presented, mentioning major achievements and current issues to be explored. [ABSTRACT FROM AUTHOR]

The electrochemical performance of gold electrode in sulfuric acid was studied with addition of different concentrations of dissolved fullerenol-d with C60(OH)24 chemical formula. Based on the cyclic voltammetry data, the conclusion of surface complexation of Au(III) with fullerenol was made. The scheme was suggested to describe the electrode process, based on catalysis of anodic Au dissolution by fullerenol molecules. The technique was suggested to detect fullerenol-d (C60(OH)24) in concentration range from 2.6·10–9 M to 2.0·10–7 M by means of cyclic voltammetry of gold in aqueous sulfuric acid solution. [ABSTRACT FROM AUTHOR]

Development of high capacity and long cycle life electrode materials is essential to improving energy storage capacity in electrochemical rechargeable devices. In order to be commercially viable, the synthesis of these materials must be straightforward, cost-effective, and ideally a single-step process. We present a binder-free synthesis method for nickel phosphate hydrate (NiPH) and nickel molybdenum phosphate hydrate (NiMoPH) on nickel foam via a simple hydrothermal process. X-ray diffraction (XRD) patterns confirmed the formation of NiPH and NiMoPH phases, while X-ray photoelectron spectroscopy (XPS) verified the presence of nickel (Ni), molybdenum (Mo), phosphorus (P), and oxygen (O) in the composite. Scanning electron microscopy (FE-SEM) revealed the formation of micro-flowers with plate-like structures in NiPH, which transformed into hexagonal rod-like structures upon the introduction of molybdenum in NiPH. This morphological and phase modification increased the charge storage capacity from 1441 mF/cm2 (NiPH) to 2945 mF/cm2 (NiMoPH) at 20 mA/cm2. The NiMoPH electrode demonstrated excellent capacitance retention of 91.8 % over 10,000 cycles. Additionally, asymmetric supercapacitor (ASS) devices were fabricated using NiPH and NiMoPH as positive electrodes and activated carbon (AC) as the negative electrode. The NiPH//AC and NiMoPH//AC configurations exhibited energy densities of 0.086 and 0.201 mWh/cm2, respectively, with the NiMoPH//AC device maintaining about 90 % capacitance retention over 15,000 cycles. This study demonstrates the potential of incorporating conductive transition metals to enhance electrode material performance in energy storage applications. Hydrothermally synthesized nickel phosphate hydrate (NiPH) and nickel molybdenum phosphate hydrate (NiMoPH) electrode materials for energy storage devices have been reported. The transformation of NiPH microplates into hexagonal rods upon the addition of molybdenum was observed. This structural modification and improved conductivity, induced by the inclusion of molybdenum, enhances the electrochemical energy storage performance of the electrodes. [Display omitted] [ABSTRACT FROM AUTHOR]

This paper presents a comprehensive study and performance analysis of all-oxide thin-film Au/Pt/Ba 0.5 Sr 0.5 TiO 3 /SrMoO 3 varactors with 100 nm Ba 0.5 Sr 0.5 TiO 3 (BST) tunable dielectric layers doped with 1%, 3% and 5% of Mn and Ni grown epitaxially on a 600 nm SrMoO 3 bottom electrode. Performance parameters such as tunability, quality factor, figure-of-merit, leakage current and acoustic resonances of the varactors are investigated. The investigation covers frequencies up to 6 GHz and a broad temperature range from − 40 ∘ to 80 ∘ , using biasing field strengths of up to ± 100 V/μm, in order to evaluate the feasibility and the performances of BST-doped all-oxide varactors for sub-6 GHz applications. Results confirm the anticipated advantages of Mn and Ni doping: a substantial reduction in leakage current along with an increase in quality factor, however, at the cost of reduced tunability. The observed acoustic resonances are shifted towards higher frequencies as compared to those for varactors with undoped BST, which implies in a larger frequency operating range for doped all-oxide varactors. In addition, the amplitudes of the acoustic resonances decline with doping. Moreover, they can be effectively suppressed for thinner BST layers, which has been proved exemplarily for a varactor with a 25 nm Mn-doped BST layer and a tunability of 55 %, requiring an ultimately low tuning voltage of only 2.9 V. [ABSTRACT FROM AUTHOR]

The increasing demands for precision and efficiency in machining processes, driven by advancements in aerospace, biomedical, and automotive industries, have led to a growing need for highly accurate machined parts. Stainless steel 316, a commonly used material in these sectors, presents specific challenges due to its intended applications, particularly in biomedical and aerospace fields. Electric discharge machining (EDM) is a favored method for working with this alloy. However, EDM has inherent challenges, such as dimensional overcuts, which have limited its applicability. To address these issues, the potential of three different electrode materials, namely, copper (Cu), brass, and aluminum (Al), has been extensively explored. Additionally, the choice of the optimal dielectric is crucial as it directly affects the heat input to the electrode, influencing the melting and vaporization of the tool wear. In this context, the inclusion of graphene as an additive has been explored to minimize radial overcuts. It is worth noting that these concerns have not been comprehensively addressed before. The experimental design by Taguchi has been employed for the research, and the results indicate that the performance of the Cu electrode surpasses that of other dielectrics. The artificial intelligence-based artificial neural network (ANN) was constructed to predict the values of OC. It was found that in the given dataset, the R2 has a value greater than 0.99 for all possible training and validation. Based on the ANN, a multi-objective optimization through genetic algorithm (MOGA) was performed. It was found that the dimensional accuracy achieved by Cu electrode was 70.51% better than the highest OC value given by same electrode. Moreover, the OC suggested by the MOGA for brass and Al electrodes was 40.21% and 34.37% better compared to the highest values of radial overcut obtained during the actual experimentation. [ABSTRACT FROM AUTHOR]

In this article, the review on different modeling approaches used for the dispersion of conductive slurries is presented. It comprises three parts: state‐of‐the‐art dispersion process, physiochemical properties, and different modelling approaches. The first part explains the physical mechanism involved in the mixing process and gives an in‐depth understanding of the applicability of the current techniques available commercially with respect to lab‐scale, pilot plant, and industrially upscaled production of these conductive slurries. The main challenges in slurry formulation prevent the formation of agglomerates and breaking down the preexisting agglomerates. It can be understood by studying the role of process parameters such as mixing time and stirring speed involved in the dispersion process. The second part focusses on the important physiochemical properties such as solid content, particle size distribution, and rheology that influences the electrode performance. The third part focusses on the available modelling approaches based on computational‐fluid‐dynamics‐ and coarse‐grained‐molecular‐dynamics‐based on the need as well as the complexity involved. The important aspects such as accuracy, computational cost, advantages, and limitations for both these approaches are discussed that will help the readers to select an appropriate technique in the modelling paradigm to reduce the energy consumption in the dispersion process. [ABSTRACT FROM AUTHOR]

Cu-based chalcogenide materials exhibit significant promise for the development of Zn-metal-free anode materials for aqueous Zn-ion batteries (AZIBs). Here, we present the establishment of an efficient and universal strategy that capitalizes on the pyrolysis of copper nanoclusters to fabricate conversion-type Cu7S4 anodes engineered for AZIBs, showcasing outstanding electrochemical performance. Furthermore, by exploiting ligand engineering, we enable the precise control of both the type of molecular fragments generated during nanocluster pyrolysis, thus enabling the manipulation of vacancy concentrations and ion/electron migration in the resultant pyrolysis products. In contrast to the direct pyrolysis of metal salts and ligands, the products derived from copper nanoclusters exhibit enhanced specific capacity, rate performance, and overall stability. This research offers valuable insights for the development of novel electrode materials through the pyrolysis of atomically precise nanoclusters. [ABSTRACT FROM AUTHOR]

Compared to nanostructured Si/C materials, micro-sized Si/C anodes for lithium-ion batteries (LIBs) have gained significant attention in recent years due to their higher volumetric energy density, reduced side reactions and low costs. However, they suffer from more severe volume expansion effects, making the construction of stable micro-sized Si/C anode materials crucial. In this study, we proposed a simple wet chemistry method to obtain porous micro-sized silicon (μP-Si) from waste AlSi alloys. Then, the μP-Si@carbon nanotubes (CNT)@C composite anode with high tap density was prepared by wrapping with CNT and coated with polyvinylpyrrolidone (PVP)-derived carbon. Electrochemical tests and finite element (FEM) simulations revealed that the introduction of CNTs and PVP-derived carbon synergistically optimize the stability and overall performance of the μP-Si electrode via construction of tough composite interface networks. As an anode material for LIBs, the μP-Si@CNT@C electrode exhibits boosted reversible capacity (∼ 3500 mAh·g−1 at 0.2 A·g−1), lifetime and rate performance compared to pure μP-Si. Further full cell assembly and testing also indicates that μP-Si@CNT@C is a highly promising anode, with potential applications in future advanced LIBs. It is expected that this work can provide valuable insights for the development of micro-sized Si-based anode materials for high-energy-density LIBs. [ABSTRACT FROM AUTHOR]

Lithium‐sulfur batteries are emerging as sustainable replacements for current lithium‐ion batteries. The commercial viability of this novel type of battery is still under debate due to the extensive use of highly reactive lithium‐metal anodes and the complex electrochemistry of the sulfur cathode. In this research, a novel sulfur‐based battery has been proposed that eliminates the need for metallic lithium anodes and other critical raw materials like cobalt and graphite, replacing them with biomass‐derived materials. This approach presents numerous benefits, encompassing ample availability, cost‐effectiveness, safety, and environmental friendliness. In particular, two types of biochar‐based anode electrodes (non‐activated and activated biochar) derived from spent common ivy have been investigated as alternatives to metallic lithium. We compared their structural and electrochemical properties, both of which exhibited good compatibility with the typical electrolytes used in sulfur batteries. Surprisingly, while steam activation results in an increased specific surface area, the non‐activated ivy biochar demonstrates better performance than the activated biochar, achieving a stable capacity of 400 mA h g−1 at 0.1 A g−1 and a long lifespan (>400 cycles at 0.5 A g−1). Our results demonstrate that the presence of heteroatoms, such as oxygen and nitrogen positively affects the capacity and cycling performance of the electrodes. This led to increased d‐spacing in the graphitic layer, a strong interaction with the solid electrolyte interphase layer, and improved ion transportation. Finally, the non‐activated biochar was successfully coupled with a sulfur cathode to fabricate lithium‐metal‐free sulfur batteries, delivering a specific energy density of ~600 Wh kg−1. [ABSTRACT FROM AUTHOR]

Zinc hydroxide [Zn(OH)2] is a multifaceted substance with significant potential in diverse domains such as energy storage, catalysis, and environmental cleanup. Zn(OH)2 is appropriate for pseudocapacitor applications because of its strong electrochemical activity, cost-effectiveness, and environmentally favorable features. In this investigation, we have effectively synthesized nanoflakes of zinc hydroxide [Zn(OH)2] as electrode material on stainless steel substrates for supercapacitor applications using the successive ionic layer adsorption and reaction (SILAR) technique. The performance of the electrode material is enhanced by nanoflakes, which encourage electrolyte diffusion and provide more channels for ion migration. Optical absorption analysis unveiled a direct band transition, showcasing a band gap of 3.35 eV. The synthesized material underwent characterization through scanning electron microscopy (SEM) and X-ray diffraction (XRD), confirming their well-defined morphology and crystalline structure with uniform distribution. The cyclic voltammetry as well as galvanostatic charge–discharge experiments were performed in a three-electrode configuration using a 1 M KOH aqueous electrolyte. The electrochemical results demonstrated that the Zn(OH)2 nanoflakes thin film electrode revealed a remarkable specific capacitance of 123 F g−1 at a current density of 1 A g−1. Additionally, it displayed an extended cycling lifespan, retaining 72% of its original capacitance even afterward undergoing 5000 cycles at a scan rate of 100 mV s−1. [ABSTRACT FROM AUTHOR]

The article delves into the synthesis and characterization of MoS2-carbon-based materials, holding promise for applications in supercapacitors and ion batteries. The synthesis process entails the preparation of MoS2 and its carbon hybrids through exfoliation, hydrothermal treatment, and subsequent pyrolysis. Various analytical techniques were employed to comprehensively examine the structural, compositional, and morphological properties of the resulting materials. The article explores the electrochemical performance of these electrode materials in supercapacitors and ion batteries (LiB, SiB, KiB). Electrochemical measurements were conducted in aqueous electrolyte for supercapacitors and various aprotic electrolytes for ion batteries. Results highlight the impact of the synthesis process on electrochemical performance, emphasizing factors such as capacitance, rate capability, and charge/discharge cycle performance. Hydrothermally treated MoS2-carbon exhibited a specific capacitance of approximately 150 F g-1 in supercapacitors, attributed to its high surface area and efficient charge storage mechanisms. Additionally, for Li-ion battery materials without hydrothermal treatment showed impressive capacity retention of around 88% after 500 charge-discharge cycles, starting with an initial specific capacity of about 920 mAh/g. Long-term stability was demonstrated in both supercapacitors and lithium-ion batteries, with minimal capacitance degradation even after extensive charge-discharge cycles. This research underscores the potential of MoS2-based materials as effective energy storage solutions. [ABSTRACT FROM AUTHOR]

Transparent electrodes (TEs) are vital in optoelectronic devices, enabling the interaction of light and charges. While indium tin oxide (ITO) has traditionally served as a benchmark TE, its high cost prompts the exploration of alternatives to optimize electrode characteristics and improve device efficiencies. Conducting polymers, which combine polymer advantages with metal‐like conductivity, emerge as a promising solution for TEs. This work introduces a two‐in‐one electron transport layer (ETL) and TE based on films of polyethylenimine ethoxylated (PEIE)‐modified poly(benzodifurandione) (PBFDO). These PEIE‐modified PBFDO layers exhibit a unique combination of properties, including low sheet resistance (130 Ω sq−1), low work function (4.2 eV), and high optical transparency (>85% in the UV–vis‐NIR range). In contrast to commonly used poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), the doping level of PBFDO remains unaffected by the PEIE treatment, as verified through UV–vis‐NIR absorption and X‐ray photoelectron spectroscopy measurements. When employed as a two‐in‐one ETL/TE in organic solar cells, the PEIE‐modified PBFDO electrode exhibits performance comparable to conventional ITO electrodes. Moreover, this work demonstrates all‐organic solar cells with record‐high power conversion efficiencies of >15.1% under indoor lighting conditions. These findings hold promise for the development of fully printed, all‐organic optoelectronic devices. [ABSTRACT FROM AUTHOR]

An iterative design process of polymer fabric from point to line and plane, inspired by the fabric craft, has been rationally designed to improve the electrochemical performance of organic electrode materials (OEMs) in rechargeable metal–organic batteries (MOBs). The evolution from point to line and plane of OEM improves its structure stability, kinetics, and utilization of active sites, benefitting the construction of high-performance MOBs. [Display omitted] Organic electrode materials (OEMs) have attracted significant attention for use in aqueous zinc-ion batteries (AZIBs) because of their abundant resources and flexible designability. However, the development of high-performance OEMs is strongly hindered by their high solubility, poor conductivity, sluggish ion diffusion kinetics, and difficult coordination toward Zn2+. Herein, inspired by fabric crafts, we have designed a robust polymer fabric through the iterative evolution of the building blocks from point to line and plane. The evolution from point to line could not only improve the structural stability and electrical conductivity but also adjust the active site arrangement to enable the storage of Zn2+. In addition to further boosting the aforementioned properties, the evolution from line to plane could also facilitate the construction of noninterference channels for ion migration. Accordingly, the poly(1,4,5,8-naphthalenetetracarboxylic dianhydride/2,3,5,6-tetraaminocyclohexa-2,5-diene-1,4-dione) (PNT) polymer fabric has the most enhanced structural stability, optimized active site arrangement, improved electrical conductivity, and suitable ion channels, resulting in a record-high capacity retention of 96% at a high mass loading of 56.9 mg cm−2 and a stable cycle life of more than 20,000 cycles at 150 C (1 C=200 mA g−1) in AZIBs. In addition, PNT exhibits universality for a wide range of ions in organic electrolyte systems, such as Li/Na/K-ion batteries. Our iterative design of polymer fabric cathode has laid the foundation for the development of advanced OEMs to promote the performance of metal-ion batteries. [ABSTRACT FROM AUTHOR]

To enrich the crystal growth strategies for the booming applications concerning lattice structure, a preferred facet‐growth method is proposed for solvothermal synthesis of target (BiO)2CO3 in the two‐phase system. The dominant crystal phase can be regulated from α‐Fe2O3 to (BiO)2CO3 by properly increasing dosage of Bi feedstock, and the optimized composite is composed of (BiO)2CO3 nanocrystal (≈10 nm) and amorphous iron oxide (defined as "FOB‐50"). Based on experimental characterizations and theoretical calculations, the highly matched lattice between (006)/(0012) facets of α‐Fe2O3 and {010} facet group of (BiO)2CO3 involving orientation of Fe─O─Fe bond and Bi─O─Bi bond is verified to facilitate the interaction between the above facets, resulting in preferred growth of {010} dominated by (040) facet in (BiO)2CO3 and its composites. The structural merits can not only enable the FOB‐50‐based electrodes to achieve a high capacity and unprecedentedly stable cyclic performances for 1500 cycles/a long time‐span of 32 months as anode materials, but also ensure the full‐cell to well inherit the electrochemical features of the cathode in potassium ion batteries (PIBs). This work can provide new insight into lattice regulation for bismuth‐based materials and expand their application as electrodes for high performance PIBs and lithium ion batteries. [ABSTRACT FROM AUTHOR]

The commercialization of high‐capacity silicon materials in lithium‐ion batteries is hindered by significant volume changes. Composite anodes made from silicon and graphite, which increase battery capacity and maintain electrode structural stability, are receiving considerable attention. However, the spatial configuration of the active particles in the electrode is few investigated due to the complexity of experiments at the microscopic scale. Herein, this work focuses on electrochemical, mass transport, and stress coupling mechanisms by considering different spatial configurations of silicon and graphite. In situ electrochemical and stress measurements are first conducted to demonstrate the impact of the active material arrangement. Then, a 2D electrochemical‐mechanical model is developed considering the heterogeneity of electrochemical processes at the particle‐electrolyte interface. The results show that placing silicon in the upper active layer significantly reduces the ion transport resistance, while the graphite layer near the current collector provides a good conductive network for electron transport in the silicon layer, enhancing the performance of the composite electrode structure. By combining electrochemical and mechanical field models with experimental verification, this study deepens the understanding of composite electrode structure design, offering practical guidance for optimizing the spatial configuration of electrode materials to significantly improve battery performance. [ABSTRACT FROM AUTHOR]

An enzyme‐based biofuel cell (EBFC) is widely regarded as one of the most efficient power sources for bio‐friendly and implantable medical devices, capable of converting electrochemical reactions into electrical currents under physiological conditions. However, despite its potential, the practical and commercial use of EBFCs is limited by their low power output and operational instability. Therefore, significant research efforts have focused on increasing power output and stability by improving electron transfer between enzymes and host electrodes and developing efficient enzyme immobilization techniques. However, most EBFCs produced by current methods still deliver unsatisfactory performance. A promising approach to address these challenges is the use of conductive linkers that promote favorable interfacial interactions between adjacent enzymes and between enzymes and host electrodes. These linkers can facilitate electron transfer and ensure robust enzyme immobilization. In addition, designing the host electrode with a 3D structure and a large surface area can further improve the areal energy performance. This perspective reviews the working principles, types, and electron transfer mechanisms of EBFC electrodes and explores how conductive linkers and 3D host electrodes can enhance the performance of EBFC electrodes. Finally, recent advances in integrating EBFCs into biomedical devices are described. [ABSTRACT FROM AUTHOR]

Reversible protonic ceramic electrochemical cell (R-PCEC) has demonstrated high potential as an energy storage and conversion device. Efforts have primarily concentrated on the development of oxygen electrodes being to increase their performance and reduce performance degradation. In this work, three perovskite materials, namely Ba 0.9 Co 0.2 Fe 0.7 Nb 0.1 O 3-δ (BCFN), Ba 0.8 La 0.1 Co 0.2 Fe 0.7 Nb 0.1 O 3-δ (BLCFN), and Ba 0.8 La 0.1 Co 0.2 Fe 0.7 Nb 0.1 F 0.1 O 2.9-δ (BLCFNF) are investigated. Both doping with La and co-doping with La and F lead to a notable reduction in the average valence states of Fe, Co, and Nb elements, further resulting in an increase in oxygen vacancy concentration, thereby enhancing the oxygen migration ability of the material. The H 2 O partial pressure does not have a significant impact on the polarization resistance (R p) of the oxygen electrode. Conversely, the rise in R p is highly correlated with the decrease in oxygen partial pressure, suggesting that the primary factor influencing the reaction rate of the oxygen electrode process is the exchange of oxygen ions on the surface of the electrode. BLCFNF exhibits the best oxygen migration and surface exchange ability, resulting in the lowest R p. When BLCFNF was used as the oxygen electrode in a R-PCEC with the humidity air (10%H 2 O) and humidified H 2 (3%H 2 O) as oxidant and fuel, respectively, it exhibits the highest maximum power density of 472 mW cm−2, and a current density of −682.6 mA cm−2 (1.3 V) at 650 °C. In addition, BLCFNF also shows good durability in both discharge and electrolysis process. The results indicate that La and F co-doped BLCFNF material is a promising oxygen electrode material for R-PCECs. [ABSTRACT FROM AUTHOR]

In this work, Ti/PbO2‐MWCNTs anodes modified with different amount with different amount of Tween 80 (0.0–2.0 g/L) were prepared by the direct current electrodeposition method used as anode materials for Zinc electrowinning. The MWCNTs were dispersed in a lead nitrate solution with Tween 80, and the effects of the amount of added Tween 80 on the morphology, phase composition and electrocatalytical performance of lead dioxide coating were investigated. Physical characterizations show that with the increase of the amount of Tween 80, both grain size of PbO2 and carbon content in PbO2 layer firstly increased and then decreased, the preferential orientation and crystallinity of the PbO2 grain growth in the deposition process changed. Electrochemical tests demonstrate that the optimal modified electrode achieved the minimum Eo value and maximum j0 of 2.038 V and 3.781×10−4 A, respectively, an increase of capacitance to 368.8 μF cm−2, and a decrease of charge transfer resistance to 92.74 Ω cm2, which is mainly attributed to the PbO2 electrode modified with Tween 80, coupled with the synergistic effects of MWCNTs doping. [ABSTRACT FROM AUTHOR]

The binder plays a crucial role in binding the solid electrode components and fixing them to the current collector, ensuring good contact and transformation. The high‐energy‐density cathode poses several challenges for the Polyvinylidene fluoride (PVDF) binder, such as high electrode potential, mass loading, and binding force. Although various new binders are proposed to optimize the electrochemical performance of cathode, the design focus and mechanisms often lack universality. This study introduces a design strategy for the cathode binder from the perspective of molecular structure design. The performance of the binder is optimized by adjusting the soft‐hard and hydrophilic‐hydrophobic balances of the polymer, and the effectiveness of this strategy is verified in the LiCoO2 (LCO) system. The optimized copolymer binder improves the cycling stability of the LCO electrode under high load and low binder content conditions and even achieves stable operation at a high charging voltage of 4.6 V. The mechanism for improving the performance of LCO electrodes is that the optimized binder stabilizes the electrode structure, the active material particle structure, and the active material interface. This design strategy provides a valuable reference for customizing cathode binders. [ABSTRACT FROM AUTHOR]

Designable molecular structures, unique ion‐coordination charge storage mechanisms, and resource sustainability enable organic electrode materials to become potential candidates for alkali metal‐ion batteries (AMIBs). Herein, integrating the excellent π–π stacking ability of Hexaazatriphenylene units and strong electron‐withdrawing properties of cyano (C≡N) groups into one moleuce, a π‐conjugated organic compound 1,4,5,8,9,11‐Hexaazatriphenylenehexacarbonitrile (HAT‐CN) is synthesized and systematically investigated as electrodes in Li/Na/K‐ion batteries. Explored by mechanism characterizations and density functional theory calculations, HAT‐CN can provide nine redox‐active sites for Na/K‐ions to intercalate/de‐intercalate, among which six Na/K‐ions are distributed evenly to both sides of conjugated skeletons through intermolecular intercalation and three Na/K‐ions are stored with the synergistic effect of C≡N groups. Employing HAT‐CN as electrodes, AMIBs are found to exhibit high reversible capacities, excellent rate capabilities, and stable cycle performances. After 100 cycles at the current density of 100 mA g−1, Na‐ion batteries present 415.6 mAh g−1 with a capacity fading rate of 1.2% per cycle. Meanwhile, K‐ion batteries maintain 345 mAh g−1 with a coulombic efficiency ≈100%. Li‐ion batteries display superlithiation performances with ultra‐high reversible capacity. This work emphasizes the necessity of comprehensively studying the electrochemical performance of organic electrodes in different secondary battery systems and is conducive to maximizing electrode functionality. [ABSTRACT FROM AUTHOR]

Solid-state lithium-based batteries offer higher energy density than their Li-ion counterparts. Yet they are limited in terms of negative electrode discharge performance and require high stack pressure during operation. To circumvent these issues, we propose the use of lithium-rich magnesium alloys as suitable negative electrodes in combination with Li6PS5Cl solid-state electrolyte. We synthesise and characterise lithium-rich magnesium alloys, quantifying the changes in mechanical properties, transport, and surface chemistry that impact electrochemical performance. Increases in hardness, stiffness, adhesion, and resistance to creep are quantified by nanoindentation as a function of magnesium content. A decrease in diffusivity is quantified with 6Li pulsed field gradient nuclear magnetic resonance, and only a small increase in interfacial impedance due to the presence of magnesium is identified by electrochemical impedance spectroscopy which is correlated with x-ray photoelectron spectroscopy. The addition of magnesium aids contact retention on discharge, but this must be balanced against a decrease in lithium diffusivity. We demonstrate via electrochemical testing of symmetric cells at 2.5 MPa and 30∘C that 1% magnesium content in the alloy increases the stripping capacity compared to both pure lithium and higher magnesium content alloys by balancing these effects. All-solid-state lithium-based batteries require high stack pressure during operation. Here, we investigate the mechanical, transport, and interfacial properties of Li-rich magnesium alloy and show enhanced performance at low pressure and ambient temperature for alloy-based electrodes with less than 5 at% Mg content. [ABSTRACT FROM AUTHOR]

Developing effective electrocatalysts for the nitrate reduction reaction (NO3RR) is a promising alternative to conventional industrial ammonia (NH3) synthesis. Herein, starting from a flexible laser‐induced graphene (LIG) film with hierarchical and interconnected macroporous architecture, a binder‐free and free‐standing Ru‐modified LIG electrode (Ru‐LIG) is fabricated for electrocatalytic NO3RR via a facile electrodeposition method. The relationship between the laser‐scribing parameters and the NO3RR performance of Ru‐LIG electrodes is studied in‐depth. At −0.59 VRHE, the Ru‐LIG electrode exhibited the optimal and stable NO3RR performance (NH3 yield rate of 655.9 µg cm−2 h−1 with NH3 Faradaic efficiency of up to 93.7%) under a laser defocus setting of +2 mm and an applied laser power of 4.8 W, outperforming most of the reported NO3RR electrodes operated under similar conditions. The optimized laser‐scribing parameters promoted the surface properties of LIG with increased graphitization degree and decreased charge‐transfer resistance, leading to synergistically improved Ru electrodeposition with more exposed NO3RR active sites. This work not only provides a new insight to enhance the electrocatalytic NO3RR performance of LIG‐based electrodes via the coordination with metal electrocatalysts as well as identification of the critical laser‐scribing parameters but also will inspire the rational design of future advanced laser‐induced electrocatalysts for NO3RR. [ABSTRACT FROM AUTHOR]

Water molecules confined in nanoscale spaces of 2D graphene layers have fascinated researchers worldwide for the past several years, especially in the context of energy storage applications. The water molecules exchanged along with ions during the electrochemical process can aid in wetting and stabilizing the layered materials resulting in an anomalous enhancement in the performance of supercapacitor electrodes. Engineering of 2D carbon electrode materials with various functionalities (oxygen (─O), fluorine (─F), nitrile (─C≡N), carboxylic (─COOH), carbonyl (─C═O), nitrogen (─N)) can alter the ion/water organization in graphene derivatives, and eventually their inherent ion storage ability. Thus, in the current study, a comparative set of functionalized graphene derivatives—fluorine‐doped cyanographene (G–F–CN), cyanographene (G–CN), graphene acid (G–COOH), oxidized graphene acid (G‐COOH (O)) and nitrogen superdoped graphene (G–N) is systematically evaluated toward charge storage in various aqueous‐based electrolyte systems. Differences in functionalization on graphene derivatives influence the electrochemical properties, and the real‐time mass exchange during the electrochemical process is monitored by electrochemical quartz crystal microbalance (EQCM). Electrogravimetric assessment revealed that oxidized 2D acid derivatives (G–COOH (O)) are shown to exhibit high ion storage performance along with maximum water transfer during the electrochemical process. The complex understanding of the processes gained during supercapacitor electrode charging in aqueous electrolytes paves the way toward the rational utilization of graphene derivatives in forefront energy storage applications. [ABSTRACT FROM AUTHOR]

Developing an anode material that has better performance efficiency than commercial graphite while keeping the features of economic scalability and environmental safety is highly desirable yet challenging. MOFs are a promising addition to the ongoing efforts, however, the relatively poor performance, chemical instability, and large‐scale economic production of efficiency‐proven pristine MOFs restrict their utility in real‐life energy storage applications. Furthermore, hierarchical porosity for lucid mass diffusion, high‐density lithiophilic sites are some of the structural parameters for improving the electrode performance. Herein, we have demonstrated the potential of economically scalable salicylaldehydate 3D‐conjugated‐MOF (Fe−Tp) as a high‐performance anode in Li‐ion batteries: the anode‐specific capacity achieved up to 1447 mAh g−1 at 0.1 A g−1 and 89 % of cyclic stability after 500 cycles at 1.0 A g−1 for pristine MOF. More importantly, incorporating 10 % Fe−Tp doping in commercial graphite (MOFite) significantly enhanced lithium storage, doubling capacity after 400 cycles. It signifies the potential practical utility of Fe−Tp as a performance booster for commercial anode material. [ABSTRACT FROM AUTHOR]

Designing electrolytes that are compatible with graphite anodes and possess flame‐retardant features is strongly demanded in potassium‐ion batteries (PIBs) to inhibit solvent co‐insertion and graphite exfoliation, and also stabilize the highly active potassium‐based species (e.g., KC8). Herein, a nonflammable electrolyte is designed by introducing the fluoroethers to stabilize graphite anodes, particularly at an ultralow concentration (<0.43 m) that is rarely reported before. It is discovered that intermolecular interactions can form between the 1,1,2,2‐tetrafluoroethyl‐2,2,3,3‐tetrafluoropropyl ether (i.e., HFE) diluent and trimethyl phosphate (TMP) flame‐retardant by electronegative fluorine (δ−F) and electropositive hydrogen (δ+H). The intermolecular interactions can change the potassium ion (K+) solvation structure (e.g., weakening the K+‐TMP interaction), and then determine the properties of the K+‐solvent‐anion complex at the electrode interface. a molecular interfacial model is presented with a new coordination mechanism involving the diluent to elucidate the relationship between the intermolecular interactions and electrode performance (i.e., K+‐solvent co‐insertion, or reversible K+ (de)intercalation) at the molecular scale, facilitating the design of high safety and high energy density potassium‐ion sulfur batteries. This study sheds light on the importance of intermolecular interactions to tune electrolyte properties and also opens new avenues for designing electrolytes for safe and practical PIBs. [ABSTRACT FROM AUTHOR]

Highlights: A novel gradient-layered architecture based on single-pore hollow lignin nanospheres (HLNPs)-intercalated MXene layers was created to fabricate highly stretchable (600%) and durable (1000 cycling) supercapacitor electrodes. The architecture reduced the overstacking of MXene, and the micro-chamber structure of HLNPs better utilized lignin's pseudocapacitive property to improve ion and electron accessibility (specific capacitance reached 1273 mF cm−2). HLNPs enhanced mechanical durability and capacitive stability of the integrated wrinkled electrodes during the stretch-release cycling. With the rapid development of flexible wearable electronics, the demand for stretchable energy storage devices has surged. In this work, a novel gradient-layered architecture was design based on single-pore hollow lignin nanospheres (HLNPs)-intercalated two-dimensional transition metal carbide (Ti3C2Tx MXene) for fabricating highly stretchable and durable supercapacitors. By depositing and inserting HLNPs in the MXene layers with a bottom-up decreasing gradient, a multilayered porous MXene structure with smooth ion channels was constructed by reducing the overstacking of MXene lamella. Moreover, the micro-chamber architecture of thin-walled lignin nanospheres effectively extended the contact area between lignin and MXene to improve ion and electron accessibility, thus better utilizing the pseudocapacitive property of lignin. All these strategies effectively enhanced the capacitive performance of the electrodes. In addition, HLNPs, which acted as a protective phase for MXene layer, enhanced mechanical properties of the wrinkled stretchable electrodes by releasing stress through slip and deformation during the stretch-release cycling and greatly improved the structural integrity and capacitive stability of the electrodes. Flexible electrodes and symmetric flexible all-solid-state supercapacitors capable of enduring 600% uniaxial tensile strain were developed with high specific capacitances of 1273 mF cm−2 (241 F g−1) and 514 mF cm−2 (95 F g−1), respectively. Moreover, their capacitances were well preserved after 1000 times of 600% stretch-release cycling. This study showcased new possibilities of incorporating biobased lignin nanospheres in energy storage devices to fabricate stretchable devices leveraging synergies among various two-dimensional nanomaterials. [ABSTRACT FROM AUTHOR]

This study investigates the reforming of glucose and fructose by photoelectrolyis, employing TiO 2 NTs photoanodes for the selective oxidation of the carbohydrates and Ni foam as cathode. TiO 2 NTs with different structural features were grown on Ti felt via anodizing and annealing to promote their crystallization. These electrodes were tested in aqueous solutions at three different pH values (i.e., 2, 7, and 12) both without and with the addition of biomass. When biomass was present, the hydrogen production rate increased, reaching faradic efficiencies (FEs) ∼ 100% in spite of the use of undivided cell, allowing the simultaneous production of valuable partial oxidation compounds, such as gluconic acid (GA) and formic acid (FA), with FEs of 24% and 55% respectively, and overall quantum yields of 5.67% and 4.36% respectively. The photoanodes used demonstrated high mechanical and chemical stability under all the tested conditions, with electrode performance remaining consistent over time, allowing the reuse of the same electrode for a not limited number of runs after a mild cleaning step.The results demonstrated that this photoelectrocatalytic (PEC) process is promising for both biomass valorization and H 2 production. [Display omitted] • Photoelectroreforming of glucose and fructose to produce H 2 , GA, and FA was studied. • TiO 2 NTs on Ti felt and Pt-free Ni foam were utilized as the photoanode and cathode, respectively. • A H 2 faradaic efficiency of 100% was achieved. • Both electrodes showed high mechanical and chemical stability, allowing reusability. [ABSTRACT FROM AUTHOR]

In this study, we tackle the complex and unresolved challenge of optimizing the performance of membrane electrode assemblies (MEAs) in varying relative humidity environments, which is crucial for practical fuel cell technologies. To address this challenge, we developed an innovative approach by fabricating an asymmetric membrane that integrates an ultrathin layer of hydrophilic carbon nanotubes (HCNTs) on the cathode side of the proton exchange membrane (PEM). The primary objective was to enhance the dimensional stability of the membrane by reducing water flooding-induced swelling on the cathode side. Additionally, the inclusion of the carbon nanotube layer improved the interfacial affinity with the cathode electrode. As a result, the MEA constructed using the asymmetric PEM coated with 0.065 mg cm−2 HCNTs demonstrated impressive current densities of 800 mA cm−2 and 1300 mA cm−2 at 0.7 V and 0.6 V, respectively, while achieving a maximum power density of 818 mW cm−2 under 100% relative humidity (RH). Remarkably, even when the RH was reduced to 0%, the MEA maintained a current density of 1100 mA cm−2 at 0.6 V and a maximum power density of 788 mW cm−2. Furthermore, the inclusion of the HCNTs layer significantly enhanced the stability of the MEA under low RH conditions, representing a crucial advancement in extending the lifespan of fuel cells in harsh environments. The novel structure of the MEA presented in this work offers a practical and effective strategy for enhancing the performance and stability of proton exchange membrane fuel cells (PEMFCs) insensitive to changing relative humidities. • A three-dimensional interface structure is achieved by coating HCNTs onto PEM for enhanced electrochemical performance. • The MEA performance improves in low or zero humidity with an HCNTs layer on the PEM's cathode side. • The HCNTs layer enhances water management by promoting water back diffusion from the cathode to the anode. [ABSTRACT FROM AUTHOR]

The stable and advanced catalytic symmetrical electrode material can reduce the number of electrode exchange in hydrocarbon fuel and extend the service life of symmetrical solid oxide fuel cells (SSOFCs). In this study, Sr 1.95 Fe 1.45 Ru 0.05 Mo 0.5 O 6-δ (SFRM) perovskites were developed and applied as both fuel and air electrode materials for SSOFCs for the first time. The peak power density (PPD) of SSOFC using SFRM electrodes is 583.6 mW cm−2, which is higher than that of SSOFC using SFM electrodes at 800 °C. Additionally, with an increase in reduction time, the maximum power density further increases by 20%–804.9 mW cm−2 with the exsolution of Ru–Fe antiparticles. Importantly, Ru doping results in a significant decrease in the size of exsolved nanoparticles and leads to a larger specific surface area. In the atmosphere of pure methane, Ru doped SFM increased from 130.9 to 185.1 W cm−2 compared with pure phase, and the discharge performance of SFRM electrode at 850 °C was more stable than that of SFM electrode. Thus, SFRM electrodes present a promising and viable option for enhancing the performance of SSOFCs. [Display omitted] • The SFRM symmetrical electrode has lower resistance than the pure phase SFM at both oxidation and reduction conditions. • The smaller and more uniform Ru–Fe alloy nanoparticles have more specific surface area. • Ru–Fe alloy nanoparticles have better catalytic properties and long-term stability for CH 4. • The power density of symmetrical SFRM electrode is increased by 20% with the exsolution of Ru–Fe alloy nanoparticles. [ABSTRACT FROM AUTHOR]

Solar saline water splitting is a promising approach to sustainable hydrogen production, harnessing abundant solar energy and the availability of brine resources, especially in the Atacama Desert. Bischofite salt (MgCl2·6H2O) has garnered significant attention due to its wide range of industrial applications. Efficient hydrogen production in arid or hyper arid locations using bischofite solutions is a novel and revolutionary idea. This work studied the electrochemical performance of Mn2O3 electrodes using a superposition model based on mixed potential theory and evaluated the superficial performance of this electrode in contact with a 0.5 M bischofite salt solution focusing on the hydrogen evolution reaction (HER) and oxygen reduction reaction (ORR) that occur during saline water splitting. The application of the non-linear superposition model provides valuable electrochemical kinetic parameters that complement the understanding of Mn2O3, this being one of the novelties of this work. [ABSTRACT FROM AUTHOR]

Innovations in wearable sweat sensors hold great promise to provide deeper insights into molecular level health information non‐invasively. Lactate, a key metabolite present in sweat, holds immense significance in assessing physiological conditions and performance in sports physiology and health sensing. This paper presents the development and characterization of stretchable electrodes with ultrahigh active surface area of 648 % for lactate sensing. The as‐printed stretchable electrodes were functionalized with an electron transfer layer comprising Toluidine Blue O and multi‐walled carbon nanotubes (MWCNTs), and an enzymatic layer consisting of lactate dehydrogenase with β‐Nicotinamide adenine dinucleotide as the cofactor for lactate selectivity. This sensor achieves a dual‐signal read‐out in which both electrochemical and fluorescence signals were obtained during lactate detection, demonstrating promising sensor performance in terms of sensitivity and reliability. We demonstrate the robustness of the dual‐signal sensor under simulated conditions of physical deformation and shifted excitation. Under these compromised conditions, the performance of the stretchable electrodes remained largely unaffected, showcasing their potential for robust and adaptable sensing platforms in wearable health monitoring applications. [ABSTRACT FROM AUTHOR]

[Display omitted] The rational design and synthesis of carbon nanocages with highly complex porous structures are continuously facing challenges in the development of high-performance supercapacitors (SCs). The electrochemical performance characteristics of electrodes rely on their compositions and fabrication methods. Here, we propose a universal and efficient approach for the in-situ synthesis of zeolitic imidazolate framework-8 (ZIF-8) on porous carbonized wood, where the selective utilization of hexacarbonyl molybdenum protects the structural integrity of the ZIF-8 precursor, preventing collapse during thermal treatment. The subsequent pyrolysis process leads to the formation of small-sized molybdenum carbide (MoC) which are embedded in carbon nanocages (CN). The composite electrode consists of MoC/CN embedded in a porous carbonized wood (PCW), and it shows area-specific capacity of 9.7F cm−2 and 9.4 F cm−2 at 5 mA cm−2 and 30 mA cm−2, respectively. Subsequently, the symmetric supercapacitor, with two MoC/CN@PCW electrodes exhibits a areal specific capacitance of 2.7 F cm−2 at 5 mA cm−2. Moreover, this supercapacitor maintains an capacitance retention rate of 98.5 % after 12,000 discharge cycles. The supercapacitor exhibits a power density of 6.5 mW cm−2, resulting in an energy density of 0.864 mWh cm−2. Therefore, the utilization of wood-based electrodes holds promise for energy storage systems. [ABSTRACT FROM AUTHOR]

The development of composite materials is a key area of research for enhancing the electrochemical performance of electrode materials. In this study, NiCo–S nanostructured hybrid electrode materials were prepared on nickel foam (NF) by using binary metal–organic frameworks (MOFs) as the sacrificial template through a two-step hydrothermal method. Ni–MOF was then deposited on the surface of NiCo–S/NF through the hydrothermal method and subsequently converted into Ni(OH)2 through a subsequent alkalization treatment. The duration of the Ni–MOF hydrothermal process was varied as a parameter. NiCo–S@Ni–MOF/NF was prepared through hydrothermal reaction for 6h, 9h and 12h, followed by heating in a 6M KOH solution at 75∘C for 6h in a water bath. The electrode materials with the best morphology and electrochemical properties were obtained when the hydrothermal reaction time was 6h. The optimized electrode had a specific capacity of 2533.2F ⋅g−1 at 1A ⋅g−1 and a capacity retention rate of 60.8% at 10A ⋅g−1, which indicated good rate performance. Additionally, the electrode material demonstrated excellent cycling stability, with a capacity retention rate of 95.3% after 5000 cycles at 50mV ⋅s−1. The energy density of the hybrid supercapacitor device assembled from this electrode material was 33.5Wh ⋅kg−1 when the power density was 849.89W ⋅kg−1 at a current density of 1A ⋅g−1. [ABSTRACT FROM AUTHOR]

ABSTRACT Energy‐efficient semiconducting BaS:MnS:Sb2S5 has been synthesized using a single source precursor method. The resulting dithiocarbamate metallic sulfide has an average crystallite size of 17.77 nm and a small band gap of 3.82 eV. A functional group investigation revealed the presence of several bonds, including the metal sulfide bond. This sulfide exhibited a double‐step thermal breakdown pattern. BaS:MnS:Sb2S5 particles were formed like cubes and tended to form cube‐like formations. The electrochemical charge‐storing behavior of BaS:MnS:Sb2S5 was investigated using a nickel foam electrode and a sulfide slurry. The fabricated electrode demonstrated a satisfactory capacity for charge storage, with a specific capacitance of 762.83 F g−1. This indicates a substantial amount of potential for long‐term energy storage utilizing electrodes. This electrode has a specific power density of 9084.78 W kg−1 and a low series resistance of (Rs) = 0.71 Ω, as per impedance measurements. Electro‐catalysis produced an OER overpotential and a corresponding Tafel slope of 233 mV and 157 mV/dec from the electrode. Conversely, for HER activity, the obtained overpotential and subsequent Tafel slope were 386 mV and 73 mV dec−1, respectively. [ABSTRACT FROM AUTHOR]

Ionomers based on poly(arylene piperidinium)s with varying ion exchange capacities are evaluated in different combinations of anode and cathode electrodes in anion exchange membrane fuel cells. The operational conditions are chosen with an asymmetrical regime including a dry anode with 50% relative humidity at the inlet, and full humidification at the cathode. Polarization and impedance measurements are carried out in potentiostatic steps within 0.3–0.9 V and distribution of relaxation times analysis is utilized to deconvolute resistance contributions. The results show that the best cell performance is achieved with both electrodes utilizing an ionomer with the highest ion exchange capacity (IEC) of 2.79 meq g−1. Cells built exclusively from this ionomer achieved a peak power density of 1.01 W cm−2. Deconvolution of the resistance contributions revealed the impact of water content on the effective charge transfer resistance in both electrodes and a diffusion resistance associated with the movement of water from anode to cathode side. The higher conductivity and water uptake of the high IEC ionomer resulted in a reduction of both resistance contributions, leading to the highest performance under the conditions evaluated. These findings provide important insights into how to tailor the electrode layers for optimum fuel cell output. [ABSTRACT FROM AUTHOR]

This study investigates the degradation of dark blue reactive azo (DBA) dye using the electro-Fenton process, with a focus on real-time colour monitoring to identify the most effective cathode–anode combinations for dye removal. Various electrode materials, including platinum (Pt), carbon fibre (C), silver (Ag), and copper (Cu), were tested. The combinations involving carbon fibre achieved a 75% colour removal within the first 20 minutes of electrolysis, whereas those with Pt electrodes did not exceed 15% in the same timeframe across different combinations. The results indicated that the carbon–copper (C–Cu) electrode combination, under optimized conditions, led to approximately 88% dye removal within 120 minutes. A kinetic study using a non-linear method demonstrated that the degradation followed a first-order kinetic model. To better understand the degradation mechanism, the degradation pathway of the DBA dye was predicted through a theoretical analysis using the Fukui function and supported by UV-Vis absorbance spectra, which revealed potential degradation by-products. The experimental data aligned with the theoretical spectra of potential by-products, confirming the electro-Fenton process's effectiveness in breaking down organic dye molecules. The study highlights the superior performance of carbon-based electrodes compared to platinum electrodes and underscores the importance of electrode material selection in optimizing the electro-Fenton process for dye degradation. [ABSTRACT FROM AUTHOR]

The successful application of bioelectrochemical systems in the future depends on the improving of electrode performance while decreasing material costs. This study explores the use of chitosan supported on different kinds of carbon materials to modify graphite electrode for the electricity generation performance of Geobacter sulfurreducens. The novel hierarchically carbon composites modified electrodes were obtained by a simple and environment‐friendly method. Among the proposed composites, the optimal composite CS/CB (5 h) possessed a better performance for the promotion of electrochemically active biofilm (EAB) growth and enhancing current generation compared with other composites. Based on morphological, chemical, and electrochemical evidences, we conclude that the CB was coated on the surface of CS to form the CS/CB decorated graphite electrode, and CS/CB (5 h) electrode exhibited significant load‐bearing capacity for bacteria colonization and enhanced the contact between bacteria and electrode, which improved the direct electron transfer process. The microbial three‐electrode system equipped CS/CB (5 h) device delivered a high current density of 1457±69 μA/cm2. The current density was increased to 3 times higher than that of the unmodified electrode. The use of this CS/CB (5 h) composite can substantially improves EAB growth and enhance power production of bioelectrochemical systems. [ABSTRACT FROM AUTHOR]