Electrode Fabrication Method Research Articles

Capacitive deionization and electrochemical performance of a hierarchical porous electrodes enabled by nitrogen and phosphorus doped CNTs and removable NaCl template

Capacitive Deionization (CDI) is an electrochemical desalination technique based on the electrical double layer, which accumulate salts from the water stream; however, achieving higher salt adsorption for low-concentration salt is hindered due to several obstacles, such as low adsorption capacity and slow kinetics on the electrode surface. In this study, we reported a novel electrode fabrication method designed to enhance the hydrophilicity of the electrode material and activate hierarchical porosity, making a more accessible adsorption surface area. This modification enables more than 210 % improvement in salt adsorption capacity, achieving 17.5 mg g-1 in a single pass process with good stability in an 850 mg/L NaCl solution at 1.2 V, surpassing most reported carbon-based electrodes under similar operating conditions. Electrode formulation consists of Nitrogen (N) and Phosphorus (P) doped hierarchical carbon nanotubes (CNTs) network blended with additional NaCl as a green and removable template to reach higher levels of porosity. The electrochemical sorption behavior of the sample was characterized over a voltage range of –0.5 to 0.7 V. Furthermore, the electrode materials were characterized utilizing various characterization methods, including Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-ray Diffraction (XRD), Raman Spectroscopy, Fourier Transformed Infrared (FTIR), X-ray Photoelectron Spectroscopy (XPS), and Brunauer-Emmett-Teller (BET) to explore the correlation between microstructure, morphology, and properties. Our finding reveals that not only N and P can affect adsorption, but also the novel cathode preparation method, which employs a removable NaCl templated hierarchical porous electrode, has a profound effect on the electrochemical and CDI results. This finding will open a new perspective in designing electrodes for all electrochemical systems.

Enhancing electrochemical kinetics in electrophoretic-deposited lithium iron phosphate Li-metal batteries through additives

This study demonstrates that the introduction of additives into the Electrophoretic Deposition (EPD) process significantly enhances the electrochemical performance of Lithium Iron Phosphate (LFP) electrodes. Incorporating these additives resulted in achieving a battery capacity of around 100 mAh/g at a 2 C rate, demonstrating a significantly higher capacity compared to configurations without additives. The additives enhance the surface capacitive effect, thus improving the efficiency of energy storage. This performance boost is attributed to a carefully optimized mixture of binders and conductive agents, resulting in a denser electrode surface. Such a surface facilitates improved Li-ion diffusion and capacitive charge storage, leading to enhanced electrochemical kinetics. These developments highlight the efficacy of the EPD method in advancing LFP electrode technology, providing a significant improvement in performance by enabling pseudocapacitive behavior and better Li-ion transport. Our findings suggest promising avenues for the evolution of future battery technologies, marking a notable step forward in electrode fabrication methods.

Synthesis and Characterization of 3D MnNi2O4@MnNi2S4/NF-MOF-67-rGO nanoflower@nanosheet for ultra-high capacity electrode material

Abstract This study reports a novel 3D MnNi2O4@MnNi2S4/NF-MOF-67-rGO core-shell nanoflower@nanosheet synthesized at very high temperature and pressure shows an outstanding electrode substance for ultra-high super capacitor. The structure of MnNi2O4@MnNi2S4 was determined by using infrad red spectrum, scanning electron microscopic images and cyclic voltammetric techniques. The core (MnNi2O4) and shell (MnNi2S4) are both dynamic resources and they are involved in the Faraday redox processes to make possible the MnNi2O4@MnNi2S4 conducting device to acquire more electrochemical properties. The power capacitance of the MnNi2O4@MnNi2S4 electrode material reaches 805.09 C g−1 while the density of the current is 1.0 A g−1. Furthermore, the preservation rate of specific capacity of the MnNi2O4@MnNi2S4 electrode reaches 91.50% after the five thousand charge - discharge cycles while the density of current is 20.0 A g−1. The energy density for the MnNi2O4@MnNi2S4//AC material attains 74.64 Wh kg−1 at a energy density of 774.05 Wh kg−1. In addition, the MnNi2O4@MnNi2S4 //AC shows exceptional self-discharge properties. Therefore, the MnNi2O4@MnNi2S4 conducting device presents wide-ranging utilities and applications for capacitors of the battery-type. In this work, a novel 3D MnNi2O4@MnNi2S4 /NF-MOF-67-rGO core-shell nano arrangement was effectively grown-up on the Nickel foam via the reaction mixture growth technique, which misplaced the conductive additive and addition of binder and the complex method of electrode fabrication. It is quite remarkable that the maximum energy storage capacity of the 3D MnNi2O4@MnNi2S4/NF-MOF-67-rGO reaches 3579.60 F g−1 at the current density of 1.0 A g−1 and 1008.50 F g−1 at the current density of 20.0 A g−1. At a given density of current of 15.0 A g−1, the retention rate of maximum energy storage capacity reaches 94.10 % after 5 cycles, showing excellent cycling performances.

Binder-free, multidentate bonding-induced carbon nano-oligomer assembly for boosting charge transfer and capacitance of energy nanoparticle-based textile pseudocapacitors

Energy storage performance of pseudocapacitors (PCs) critically depends on the integration and distribution of electrochemically active materials and conductive fillers as well as the intrinsic energy storage capacity of active materials. This is particularly challenging for nano-sized pseudocapacitive materials that offer high energy density but suffer from low electrical conductivity. Additionally, conventional electrode fabrication methods often neglect crucial interfacial interactions and electrolyte wettability essential for nanoparticle-based PC electrodes in a 3D structure, which can lead to performance degradation. Here, we present a novel approach to fabricate 3D-structured pseudocapacitor electrodes by directly and sequentially assembling hydrophobic energy nanoparticles (NPs) and hydrophilic carbon nano-oligomers (CNOs) with branched space arms onto 3D textile current collectors, eliminating the need of insulating and hydrophobic organic components. This assembly based on direct interfacial multidentate interactions between MnOx NPs and CNOs ensure a uniform nano-level distribution over the entire metallic textile surface. The resulting positive electrodes (i.e., MnOx NP/CNO-based textiles) exhibit the outstanding areal capacitance of ∼1,725 mF cm−2 at 5.0 mA cm−2. This capacitance can be further increased to ∼3,244 mF cm−2 at 10 mA cm−2 via a multi-stacking method. When paired with negative electrodes (i.e., Fe3O4 NP/CNO-based textiles) fabricated using the same approach, asymmetric full-cell demonstrate remarkable areal energy/power densities that surpass those of conventional pseudocapacitors.

Effect of electrode materials and fabrication methods on resistive switching behavior of poly(3-hexylthiophene-2,5-diyl)-based resistive random access memory

Effect of electrode materials and fabrication methods on resistive switching behavior of poly(3-hexylthiophene-2,5-diyl)-based resistive random access memory

Highly Conductive Films Through PEDOT‐PSS Ink Formulation via Doping Using Spontaneous Wicking of Liquids for Supercapacitor Applications

A novel electrode fabrication method based on liquid doping of PEDOT‐PSS onto PET‐G film by drop casting is reported. A dispersed liquid‐PEDOT‐PSS solution is prepared as an ink by a liquid doping synthesis method. The EG/DMSO:PEDOT‐PSS solution is then drop cast onto oxygen plasma‐modified PET‐G films for electrode fabrication. Their surface topography and electrochemical characteristics are characterized. The results show that the prepared electrode material has an electrical conductivity of 11661.7 and 11528.8 S m−1 for EG‐ and DMSO‐treated PEDOT‐PSS films, respectively. Ink formulation achieves unprecedented conductivity via spontaneous liquid wicking. The specific capacitance is 134 F g−1 at a scanning rate of 5 mV s−1 and 309.6 F g−1 at a scanning rate of 20 mV s−1 for EG and DMSO‐treated PEDOT‐PSS films, respectively, on the three‐electrode system while specific capacitance for pristine PEDOT‐PSS calculated at 80 mV s−1 is 4.6 F g−1. PEDOT‐PSS films are engineered for superior supercapacitor performance through liquid wicking. Moreover, the results of Fourier‐transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), and Raman spectroscopy measurements confirm that the removal of PSS on the surface is due to liquid–liquid doping. Energy‐dispersive X‐ray spectroscopy analysis proves the expulsion of PSS molecules from the solution interface. Therefore, the die‐cast PET‐G‐PEDOT‐PSS electrode is a promising candidate for advanced supercapacitor applications.

Selective control of sharp-edge zinc electrodes with (002) plane for high-performance aqueous zinc-ion batteries

This study introduces a novel ZnSE electrode fabrication method, stabilizing the (002) crystal plane to reduce Zn dendrite growth, lower HER, and enhance corrosion resistance.

Single-Entity Bioelectrochemistry

Interfacing biological catalytic entities, such as whole cells or enzymes, with electrodes, has a wide range of applications, ranging from fundamental studies of the entities themselves to power generation, bioremediation, chemical synthesis, and biosensing. In all cases, the operation of these bioelectrocatalytic systems is based on electron transfer phenomena within protein molecules, whether isolated or residing inside cells or parts of cells, as well as between proteins and electronics. Typically, the electron transfer and catalytic properties of proteins are studied using ensemble averaging methods, which obscure any heterogeneity and dynamics of individual molecules. This information, however, is especially important for understanding electron transfer and catalytic processes within a living cell where only one or a few protein molecules are present. While single-entity electrochemical measurements are particularly useful for studying electron transfer reactions at the nanoscale level, they have limited applications for investigating biological entities due to the experimental challenges associated with direct measurements of small electrical currents. 1,2 Here we will discuss our recent progress in investigating biological electron transfer reactions at the single-entity level, from bacterial cells to single redox proteins, using nano-impact (collision) single-entity electrochemistry. 3 We demonstrate how advances in electrode fabrication methods and detection setups enable current detection in the fA range. When combined with the developed data processing algorithm based on unsupervised learning and template matching techniques, this enabled unprecedented insight into electron transfer processes at the nanoscale. We will talk about insights provided by the method in the study of several important bioelectrocatalytic systems: single E.coli cells with overexpressed Fe-Fe hydrogenases, single bilirubin oxidase molecules, and single catalase molecules. In addition, we will discuss models that we developed for understanding the single bioentity electrode interactions for diffusion-controlled enzymes when the product of the catalytic reaction is detected on the electrode, as well as systems based on direct electron transfer between the bioentity and the electrode. Overall, we show how single-entity bioelectrochemistry can shed light on biological electron transfer and catalysis processes and discuss the challenges it currently faces. Zhang, J.-H.; Zhou, Y.-G. Nano-Impact Electrochemistry: Analysis of Single Bioentities. TrAC Trends Anal. Chem. 2019, 115768.Davis, C.; Wang, S. X.; Sepunaru, L. What Can Electrochemistry Tell Us About Individual Enzymes? Curr. Opin. Electrochem. 2020, 100643.Sekretaryova, A. N.; Vagin, M. Yu.; Turner, A. P. F.; Eriksson, M. Electrocatalytic Currents from Single Enzyme Molecules. J. Am. Chem. Soc. 2016, 138 (8), 2504–250

Sustainable Laser Induced Supercapacitors from Cork Natural Substrates

A novel type of eco-friendly and cost-effective supercapacitor has been developed by fabricating interdigitated and squared supercapacitors made of porous graphitic carbon electrodes and Polyvinyl alcohol (PVA) electrolyte. The electrodes were fabricated using a simple, fast, and low-cost laser engraving process, using visible irradiation wavelengths (450 nm) and performed under ambient conditions, resulting in highly three-dimensional, electrically conductive, and porous graphitic carbon structures.By adjusting the laser power and wavelength, it was possible to produce electrode materials with highly porous and high surface area morphology, which are promising for electrochemical applications. Spectral investigation using Raman and FTIR spectroscopies confirmed the formation of graphitic carbon structures and the full conversion of the cork precursor under visible laser irradiation.The obtained electrodes exhibited excellent supercapacitive behavior when exposed to a PVA electrolyte, achieving a specific areal capacitance of up to 11.24 mF/cm2 with PVA at 30% laser power. The supercapacitive properties showed excellent stability over time, with no significant loss after 10000 charge/discharge cycles.To evaluate the performance of the new supercapacitors, linear electrodes were used as working electrodes in a three-electrode configuration electrochemical cell. The electrodes showed diffusion-limited electrochemical behavior with fast heterogeneous electron transfer rates (HET), which was superior to that of traditional glassy carbon electrodes.The innovative and efficient electrode fabrication method presented in this study, which utilizes low-cost instrumentation, environmentally friendly fabrication methods, and Earth-abundant precursor materials, shows great promise for producing large-scale "green" electrochemical sensing platforms and devices in the future.

Engineering electrode interfaces for telecom-band photodetection in MoS2/Au heterostructures via sub-band light absorption

Transition metal dichalcogenide (TMD) layered semiconductors possess immense potential in the design of photonic, electronic, optoelectronic, and sensor devices. However, the sub-bandgap light absorption of TMD in the range from near-infrared (NIR) to short-wavelength infrared (SWIR) is insufficient for applications beyond the bandgap limit. Herein, we report that the sub-bandgap photoresponse of MoS2/Au heterostructures can be robustly modulated by the electrode fabrication method employed. We observed up to 60% sub-bandgap absorption in the MoS2/Au heterostructure, which includes the hybridized interface, where the Au layer was applied via sputter deposition. The greatly enhanced absorption of sub-bandgap light is due to the planar cavity formed by MoS2 and Au; as such, the absorption spectrum can be tuned by altering the thickness of the MoS2 layer. Photocurrent in the SWIR wavelength range increases due to increased absorption, which means that broad wavelength detection from visible toward SWIR is possible. We also achieved rapid photoresponse (~150 µs) and high responsivity (17 mA W−1) at an excitation wavelength of 1550 nm. Our findings demonstrate a facile method for optical property modulation using metal electrode engineering and for realizing SWIR photodetection in wide-bandgap 2D materials.

Supercapacitors: Review of materials and fabrication methods

It is hoped that supercapacitors will power devices in the future. Future hybrid electric automobiles and other electrical infrastructure will benefit from these parts. Improving supercapacitors' energy and power densities is essential to tap into their potential fully. Improvements in electrode materials and fabrication methods could solve this problem. The development of better supercapacitor electrodes has necessitated the production of several different materials during the past few years. It is prudent to investigate all facets of supercapacitor units due to the rapid development of technology. This paper reviews a brief overview of the broad spectrum of current supercapacitors. Modern fabrication methods, materials for supercapacitors, and their future potential are analysed. Also discussed the main technical obstacles that could hinder future growth efforts in various industries.

Fabrication of nanofibrous PbO2 electrode embedded with Pt for decomposition of organic chelating agents

A new fabrication method of nanofibrous metal oxide electrode comprising Pt nanofiber (Pt–NF) covered with PbO2 on a Ti substrate was proposed. Pt–NF was obtained by performing sputtering deposition of Pt on the surface of electrospun poly(vinyl alcohol) (PVA) nanofiber on a Ti substrate, in which PVA was then removed by calcination (Ti/Pt–NF). Subsequently, by introducing PbO2 to the Ti/Pt–NF using the electrodeposition method, a nanofibrous Ti/Pt–NF/PbO2 electrode was finally obtained. Because the Ti substrate was covered by nanofibrous Pt, it had no environmental exposure and thus, was not oxidized during calcination. The crystal structure of the PbO2 mainly consisted of β-form rather than α-form; the β-form was suitable for electrochemical decomposition and remained stable even after 20 h of use. The nanofibrous Ti/Pt–NF/PbO2 electrodes showed 10% lower anode potential, 1.6 times higher current density at water decomposition potential, lower electrical resistance in the ion charge transfer resistance, and 2.27 times higher electrochemically active surface area than those of a planar-type Ti/Pt/PbO2 electrode, and demonstrated excellent electrochemical performance. As a result, compared with the planar electrode, the Ti/Pt–NF/PbO2 electrode showed more effective electrochemical decomposition toward nitrilotriacetic acid (80%) and ethylenediaminetetraacetic acid (83%), which are commonly used as chelating agents in nuclear decontamination.

Pencil-drawn graphitic traces on sticky note paper for wearable electronics

Pencil-on-sticky note paper electrodes (PeoS) is a novel electrode fabrication method, using graphite from a pencil lead as an active material and sticky note paper as the substrate. This technique offers a low-cost and simple alternative for the fabrication of electrochemical sensors. In this paper, we aim to investigate the potential of PeoS as an effective electrode material for wearable electronic applications. The SEM images show overlapping graphite flakes, and the resistance of graphitic electrodes is found to be greater for xerox paper than for sticky note paper. An RC circuit based on sticky note paper yields the true nature for the square wave input. A bending test of the pencil-on-sticky note paper circuit shows an almost constant resistance value, showing PeoS has the potential to be used as a cost-effective alternative to traditional electrodes in wearable electronic applications, providing promising results for the future of non-invasive measurements of electrical signals.

Simple-structured hydrophilic sensors for sweat uric acid detection with laser-engraved polyimide electrodes and cellulose paper substrates

Accurate detection of uric acid (UA) is crucial for diagnosing gout, yet traditional sweat-based UA sensors continue to face challenges posed by complex and costly electrode fabrication methods, as well as weakly hydrophilic substrates. Here, we designed and developed simple, low-cost, and hydrophilic sweat UA detection sensors constructed by carbon electrodes and cellulose paper substrates. The carbon electrodes were made by carbonized polyimide films through a simple, one-step laser engraving method. Our electrodes are porous, possess a large specific surface area, and are flexible and conductive. The substrates were composed of highly hydrophilic cellulose paper that can effectively collect, store, and transport sweat. The constructed electrodes demonstrate high sensitivity of 0.4 µA L µmol−1 cm−2, wide linear range of 2–100 µmol/L. In addition, our electrodes demonstrate high selectivity, excellent reproducibility, high flexibility, and outstanding stability against mechanical bending, temperature variations, and extended storage periods. Furthermore, our sensors have been proven to provide reliable results when detecting UA levels in real sweat and on real human skin. We envision that these sensors hold enormous potential for use in the prognosis, diagnosis, and treatment of gout.

Fabrication of a low-cost efficient novel Ti3AlC2 MAX phase / Polyvinyl alcohol / Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) polymer nanocomposite film for symmetric supercapacitor

ABSTRACT This work reports a systematic study of the electrochemical performance of the Ti3AlC2 MAX phase/PVA-PEDOT: PSS + DMSO polymer nanocomposite (PPM) films fabricated by the facile solution cast technique. A varying weight percentage of Ti3AlC2 MAX phase nanoparticles were dispersed in the polyvinyl alcohol (PVA)-[poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) + dimethyl sulfoxide)] (PEDOT: PSS + DMSO) polymer blend to fabricate the polymer nanocomposite films. The structural, morphological, optical, thermal, electrical, and electrochemical properties of the nanocomposite films were studied meticulously. The structural and morphological studies were done by using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction technique (XRD), and field emission scanning electron microscopy (FESEM). The optical properties of the PPM films were analyzed using the UV-Visible (UV-Vis) spectra. The thermal analysis of the PPM films was done from the thermogravimetric analysis (TGA) curves. The ac conductivity and dynamic mechanical analysis (DMA) were done to evaluate the electrical conductivity and mechanical properties of the PPM films. The performance enhancement of the polymer blend film by loading Ti3AlC2 MAX phase nanofiller was investigated. The nanocomposite film having the highest conductivity and the greatest mechanical strength was further considered for the electrochemical characterization. The nanocomposites reported a specific capacitance of 52.8 F/g and 1500 mF/g in 0.1 M HCl electrolyte at a scan rate of 20 mV/s in the 3-electrode system and 2-electrode system, respectively. The Nyquist plots and Bode plots were plotted from the electrochemical impedance spectroscopy (EIS) data. The Nyquist plots were analyzed from the simulated equivalent circuits. The facile fabrication method of the supercapacitor electrode with improved thermal and mechanical properties will be beneficial for their commercial electrochemical applications in the future.

Mechanical Properties of PEMFC Electrodes According to Fabrication Methods

Electrodes in a polymer electrolyte membrane fuel cell (PEMFC) are the crucial element performing electrochemical reactions and are the most vulnerable mechanically. Various operating conditions (freeze-thaw, start-up, shut down) generate buckling, cracks, and delamination in electrodes. These mechanical failures not only directly affect the performance of the PEMFC cell but also act as a fatal factor in shortening the lifespan. Therefore, understanding and improving the mechanical properties of electrodes is essential for designing high-durability PEMFCs. Furthermore, the fabrication method of electrodes is a factor that causes not only performance but also distinct mechanical property differences since it determines their internal structure and surface characteristics. However, evaluating the mechanical properties of electrodes has been challenging because they are fragile and hard to separate from substrates. Therefore, this study evaluated the intrinsic mechanical behaviors of the electrodes according to fabrication methods via a free-standing tensile test. The effect of fabrication methods was analyzed for blade coating and spray coating methods used universally from industry to laboratory. The difference in mechanical properties between the two methods was identified by analyzing the internal structure and distribution of ionomer agglomerate. For blade-coated electrodes, modulus (372.5 MPa) and elongation (2.44%) were 2-2.7 times higher than spray-coated electrodes (172.9 MPa,0.9%). The difference in mechanical properties originated from the electrodes’ surface and internal structures. Blade-coated electrodes were composed of smaller pores and volume than the spray coating using FIB-SEM. The modulus ratio according to the internal structure through finite element analysis (using ABAQUS software) was consistent with the actual experimental value. In addition, blade-coated electrodes have high elongation and strength because they enable uniform stress transmission with a smooth surface and uniform ionomer binder distribution (analyzed by HAADF-STEM and EDS). This study contributes to a better understanding of the mechanical properties of electrodes according to the fabrication methods and provides guidelines for mechanical improvement. Figure 1

The Cleanroom-Free, Cheap, and Rapid Fabrication of Nanoelectrodes with Low zM Limits of Detection.

Nanoscale electrodes have been a topic of intense research for many decades. Their enhanced sensitivities, born out of an improved signal-to-noise ratio as electrode dimensions decrease, make them ideal for the development of low-concentration analyte sensors. However, to date, nanoelectrode fabrication has typically required expensive equipment and exhaustive, time-consuming fabrication methods that have rendered them unsuitable for widespread use and commercialization. Herein, a method of nanoband electrode fabrication using low cost materials and equipment commonly found in research laboratories around the world is reported. The materials' cost to produce each nanoband is less than €0.01 and fabrication of a batch takes less than 1 h. The devices can be made of flexible plastics and their designs can be quickly and easily iterated. Facile methods of combining these nanobands into powerful devices, such as complete three-electrode systems, are also displayed. As a proof of concept, the electrodes are functionalized for the detection of a DNA sequence specific to SARS-CoV-2 and found to display single molecule sensitivity.

Paper-based electrochemical biosensors for the diagnosis of viral diseases.

Paper-based electrochemical analytical devices (ePADs) have gained significant interest as promising analytical units in recent years because they can be fabricated in simple ways, are low-cost, portable, and disposable platforms that can be applied in various fields. In this sense, paper-based electrochemical biosensors are attractive analytical devices since they can promote diagnose several diseases and potentially allow decentralized analysis. Electrochemical biosensors are versatile, as the measured signal can be improved by usingmainly molecular technologies andnanomaterials to attach biomolecules, resulting in an increase in their sensitivity and selectivity. Additionally, they can be implementedin microfluidic devices that drive and control the flow without external pumping and store reagents, and improve the mass transport of analytes, increasing sensor sensitivity. In this review, we focus on the recent developments in electrochemical paper-based devices for viruses' detection, including COVID-19, Dengue, Zika, Hepatitis, Ebola, AIDS, and Influenza, among others, which have caused impacts on people's health, especially in places with scarce resources. Also, we discuss the advantages and disadvantages of the main electrode's fabrication methods, device designs, and biomolecule immobilization strategies. Finally, the perspectives and challenges that need to be overcome to further advance paper-based electrochemical biosensors' applications are critically presented.

Critical Factors to Understanding the Electrochemical Performance of All-Solid-State Batteries: Solid Interfaces and Non-Zero Lattice Strain.

All-solid-state lithium batteries have been developed to secure safety by substituting a flammable liquid electrolyte with a non-flammable solid electrolyte. However, owing to the nature of solids, interfacial issues between cathode materials and solid electrolytes, including chemical incompatibility, electrochemo-mechanical behavior, and physical contact, pose significant challenges for commercialization. Herein, critical factors for understanding the performance of all-solid-state batteries in terms of solid interfaces and non-zero lattice strains are identified through a strategic approach. The initial battery capacity can be increased via surface coating and electrode-fabrication methods; however, the increased lattice strain causes significant stress to the solid interface, which degrades the battery cycle life. However, this seesaw effect can be alleviated using a more compacted electrode microstructure between the solid electrolyte and oxide cathode materials. The compact solid interfaces contribute to low charge-transfer resistance and a homogeneous reaction between particles, thereby leading to improved electrochemical performance. These findings demonstrate, for the first time, a correlation between the uniformity of the electrode microstructure and electrochemical performance through the investigation of the reaction homogeneity among particles. Additionally, this study furthers the understanding of the relationship between electrochemical performance, non-zero lattice strain, and solid interfaces.

Lab-made flexible third-generation fructose biosensors based on 0D-nanostructured transducers

Herein, we report a scalable benchtop electrode fabrication method to produce highly sensitive and flexible third-generation fructose dehydrogenase amperometric biosensors based on water-dispersed 0D-nanomaterials.The electrochemical platform was fabricated via Stencil-Printing (StPE) and insulated via xurography. Carbon black (CB) and mesoporous carbon (MS) were employed as 0D-nanomaterials promoting an efficient direct electron transfer (DET) between fructose dehydrogenase (FDH) and the transducer. Both nanomaterials were prepared in water-phase via a sonochemical approach. The nano-StPE exhibited enhanced electrocatalytic currents compared to conventional commercial electrodes.The enzymatic sensors were exploited for the determination of D-fructose in model solutions and various food and biological samples. StPE-CB and StPE-MS integrated biosensors showed appreciable sensitivity (∼150 μA cm−2 mM−1) with μmolar limit of detection (0.35 and 0.16 μM, respectively) and extended linear range (2–500 and 1–250 μM, respectively); the selectivity of the biosensors, ensured by the low working overpotential (+0.15 V), has been also demonstrated. Good accuracy (recoveries between 95 and 116%) and reproducibility (RSD ≤8.6%) were achieved for food and urine samples.The proposed approach because of manufacturing versatility and the electro-catalytic features of the water-nanostructured 0D-NMs opens new paths for affordable and customizable FDH-based bioelectronics.