Different Types Of Electrodes Research Articles

Co-assisted strategy of sacrificial salt-template and nitrogen-doping to promote lithium storage performance of NiO-Ni/N-C frameworks

Tailoring the omnidirectional conductivity networks in nickel oxide-based electrodes is important for ensuring their long lifespan, stability, high capacity, and high-rate capability. In this study, nickel metal nanoparticles and a three-dimensional nitrogen-doped carbon matrix were used to embellish the nickel oxide composite NiO–Ni/N–C via simplified hard templating. When a porous nitrogen-doped carbon matrix is present, a rapid pathway would be established for charging and discharging the electrons and lithium ions in a lithium-ion battery, thereby alleviating the volumetric expansion of the NiO nanoparticles during the operation of the battery. Moreover, the Ni0 ions added to serve as active sites to improve the capacity of the NiO-based electrodes and strengthen their conductivities. The multielement-effects of the optimal NiO–Ni/N–C electrode leads it to exhibit a capacity of 1310.8 mAh/g at 0.1 A/g for 120 loops and a rate capability of 441.5 mAh/g at 20.0 A/g. Kinetic analysis of the prepared electrodes proved their ultrafast ionic and electronic conductivities. This strategy of hard templating reduces the number of routes required for preparing different types of electrodes, including NiO-based electrodes, and improves their electrochemical performance to enable their use in energy storage applications.

Study of bonding parameters with Al and Au wires on Pd and Ag coatings

The process of electrical connection with gold and aluminium wires to palladium and silver electrodes is studied. Parameters of the wire bonding, such as bond force, ultrasonic power, bond time and temperature of the layers, controlled by heating the substrate are varied to explore the reliability of the bonds in terms of mechanical strength, electrical conductivity and interdiffusion of particles between the electrode and functional material at different bonding conditions. The importance of this study is due to the need of electrical connectivity at the stage of wiring and packaging of gas sensors with a novel organic nanomaterial (carbyne), requiring different types of electrodes – Ohmic or Schottky - according to the measurement principle and sensor architecture. Pd and Ag are identified as the most suitable for Ohmic and Schottky contacts, respectively, because of their favourable energy level alignment at the organic/metal interface. The chosen method for bonds testing is measurement of the pull force causing bond failure. The results show that Pd coating was bondable by Au wire, and Ag coating by Al wire, as well as Au on Pd bonds have 4 times higher strength. It is found that the bonding procedure doesn’t affect negatively on the Au/Pd/carbyne interface in terms of diffusion and redistribution of metal particles, but Al/Ag/carbyne is characterized by poor adhesion and the bonds are peeled-off. The results give new knowledge for the fabrication of advanced gas sensors and for the interaction of the carbyne with different metals, which will serve as a base for further optimization of the manufacturing technology toward their commercialization.

Long‐Term Stability, Noise, and Temperature Sensitivity of Modular Porous‐Pot Electrodes Designed for Geophysical and Geotechnical Applications, and Details of Their Construction

AbstractElectrodes are used to measure a potential difference between two points. In geophysical and geotechnical applications they are often in the form of non‐polarizable porous‐pot electrodes. Here we describe the design, construction, and testing of modular and refillable electrodes, which facilitates repair as the electrodes degrade over time. We use a chemical composition based on a metal in contact with an over‐saturated electrolyte that consists of a salt of that metal and an auxiliary salt. We compare characteristics when the electrolyte is stabilized in a clay or not, and with various states of ceramic porous plugs and two types of wood plugs. Next, we assess the long‐term stability (more than 1 month), noise (periods of 1 s to 1 hr), and temperature sensitivity of different types of electrodes. Electrodes with an electrolyte and clay formula showed lower noise (0.2–0.4 μV at periods of 1–120 s), greater long‐term stability (0.05–0.5 mV/month of smooth drift), and greater consistency between samples measured than those with no clay (noise and drift values up to four times larger). The effects from different porous plugs were negligible, with similar results for ceramic and wood types. The temperature sensitivity of the electric potential was assessed, from −3 to 35°C. All electrodes showed a temperature sensitivity of about −30 μV/°C. This is considered very low compared to some commercially available electrodes. Finally, continuous long‐term laboratory and field measurements of the potential highlight the application of the new electrodes.

Use of Field Concentration for Electroluminescent Devices

AbstractField concentration is often regarded as a problematic issue in soft electronics applications, especially when using curved electrodes, and in particular, those with sharp edges. However, field concentration can be turned into an advantage with appropriate device design. Herein, the applications of field concentration in hydrogel‐elastomer devices are explored. Three different types of electroluminescent hydrogel‐elastomer devices are fabricated using different types of electrodes and different light patterns. In addition, the effect of the field concentration can be extended into the bulk of the elastomer by preparing porous silicone elastomers and filling them with silicone oil. These devices are shown to be flexible and possess both good luminance and a long lifetime.

Field emission in vacuum resonant tunneling heterostructures with high current densities

We analyse the steady-state thermal regime of a one-dimensional triode resonant tunnelling structure. The high currents generated by resonant tunnelling produce a large amount of heat that could damage the structure. Establishing the conditions under which it can operate at optimum efficiency is therefore a problem of great relevance for applications. The tunnel current is found via eigenvalues of the Schrödinger equation in quantum wells. By calculating the current generated in the device and using the energy conservation law in the electrodes, the temperature reached is obtained for different types of electrodes and the importance of heat conduction and thermal radiation is analysed. In the cases discussed, conduction is dominant. When the electrode material is copper, the temperature reached is similar to that of the thermostat for a wide range of electrode lengths, whereas when the cathode material is diamond-graphite and the anode material is copper, the temperature increases significantly as a function of length. The results obtained allow the temperature to be controlled for optimum performance of the field-emitting triode structures.

Applications of electro-catalysis municipal wastewater treatment

In the context of developing a more livable environment, people are paying more attention to the pollution problem. As the consumption of water resources increases, water pollution is one of the most serious problems people need to pay attention to the most. However, traditional methods cannot meet the requirements of treating wastewater while recovering resources. In this review, the application of electrocatalytic technology in municipal wastewater treatment is discussed. Specifically, the comparison between electrocatalysis and traditional methods is shown in this review. Various literatures on different types of materials of electrodes are included. Besides, two different types of electrodes and mechanisms of electrocatalysis and their application in multiple types of wastewater are also summarized. This review aims to arouse peoples attention to the wastewater problem and explore the further application of electrocatalytic technology in the future in order to rationally design new electrocatalytic systems for the recovery of energy and resources.

Universal transfer of full‐class metal electrodes for barrier‐free two‐dimensional semiconductor contacts

AbstractMetal–semiconductor contacts are crucial components in semiconductor devices. Ultrathin two‐dimensional transition‐metal dichalcogenide semiconductors can sustain transistor scaling for next‐generation integrated circuits. However, their performance is often degraded by conventional metal deposition, which results in a high barrier due to chemical disorder and Fermi‐level pinning (FLP). Although, transferring electrodes can address these issues, they are limited in achieving universal transfer of full‐class metals due to strong adhesion between pre‐deposited metals and substrates. Here, we propose a nanobelt‐assisted transfer strategy that can avoid the adhesion limitation and enables the universal transfer of over 20 different types of electrodes. Our contacts obey the Schottky–Mott rule and exhibit a FLP of S = 0.99. Both the electron and hole contacts show record‐low Schottky barriers of 4.2 and 11.2 meV, respectively. As a demonstration, we construct a doping‐free WSe2 inverter with these high‐performance contacts, which exhibits a static power consumption of only 58 pW. This strategy provides a universal method of electrode preparation for building high‐performance post‐Moore electronic devices.

A Review of Yarn-Based One-Dimensional Supercapacitors.

Energy storage in a one-dimensional format is increasingly vital for the functionality of wearable technologies and is garnering attention from various sectors, such as smart apparel, the Internet of Things, e-vehicles, and robotics. Yarn-based supercapacitors are a particularly compelling solution for wearable energy reserves owing to their high power densities and adaptability to the human form. Furthermore, these supercapacitors can be seamlessly integrated into textile fabrics for practical utility across various types of clothing. The present review highlights the most recent innovations and research directions related to yarn-based supercapacitors. Initially, we explore different types of electrodes and active materials, ranging from carbon-based nanomaterials to metal oxides and conductive polymers, that are being used to optimize electrochemical capacitance. Subsequently, we survey different methodologies for loading these active materials onto yarn electrodes and summarize innovations in stretchable yarn designs, such as coiling and buckling. Finally, we outline a few pressing research challenges and future research directions in this field.

Study on Power Frequency Breakdown Characteristics of Nano-TiO2 Modified Transformer Oil under Severe Cold Conditions

With 45# transformer oil as the base fluid, different concentrations of TiO2 nanomodified transformer oil were prepared via the thermal oscillation method. Nanomodified transformer oil with a concentration of 0.01 g/L was selected for evaluation via the breakdown test. Then, 0.01 g/L nanomodified transformer oil and ordinary 45# transformer oil were subjected to the variable control of different moisture contents and different temperatures, and breakdown tests under different types of electrodes were performed within the temperature range of −30 °C to 30 °C. The test results showed the following: Under severe cold conditions, the improvement effect of the breakdown voltage in different temperature ranges was different. Within the temperature range of −30 °C to −10 °C, the enhancement effect could reach 13% to 15%. Within the temperature range of −10 °C to 0 °C, the enhancement effect could reach 8% to 9%. Within the temperature range of 0 °C to 30 °C, the enhancement effect could reach 18% to 21%. Compared with the test results at high water contents, the improvement in the breakdown voltage amplitude of transformer oil by nanomaterials was more obvious at low water contents. In addition, nanomaterials could reduce the dispersion of the breakdown voltage to make the breakdown voltage more stable. Lastly, COMSOL was used to simulate the polarization process of nanoparticles under a uniform electric field and the influence of the trajectory of charged particles in the oil to further analyze the mechanism of the influence of nanoparticles in oil on the breakdown voltage of the oil gap. The simulation results showed that, when the particles were accelerated by the electric field, they moved irregularly. After adding nanoparticles, the charged particles were adsorbed by the nanoparticles when passing through the nanoparticles, which reduced the migration rate of charged particles in the oil. The breakdown voltage of the oil gap increased.

Comparison of speech perception in bimodal cochlear implant patients with respect to the cochlear coverage.

The hearing success of patients with bimodal fitting, utilizing both acochlear implant (CI) and ahearing aid (HA), varies considerably: While some patients benefit from bimodal CI and HA, others do not. This retrospective study aimed to investigate speech perception in bimodally fitted patients and compare it with the cochlear coverage (CC). The CC was calculated with the OTOPLAN software, measuring the cochlear duct length on temporal bone CT scans of 39patients retrospectively. The patients were categorized into two groups: CC ≤ 65% (CC500) and CC > 65% (CC600). Monaural speech intelligibility for monosyllables at asound pressure level (SPL) of 65 dB in afree-field setting was assessed before and after CI at various time points. The two groups, one with preoperative HA and one with postoperative CI, were compared. Additionally, speech intelligibility was correlated with CC in the entire cohort before CI and at the last available follow-up (last observation time, LOT). Overall, there was no significant difference in speech intelligibility between CC500 and CC600 patients, with both groups demonstrating aconsistent improvement after implantation. While CC600 patients tended to exhibit earlier improvement in speech intelligibility, CC500 patients showed aslower initial improvement within the first 3months but demonstrated asteeper learning curve thereafter. At LOT, the two patient groups converged, with no significant differences in expected speech intelligibility. There was no significant relationship between unimodal/unilateral free-field speech intelligibility and CC. Interestingly, patients with aCC of 70-75% achieved the highest speech intelligibility. Despite of the lack of asignificant correlation between CC and speech perception, patients appeared to reach their maximum in unimodal/unilateral speech perception primarily at acoverage level of 70-75%. Nevertheless, further investigation is warranted, as CC500 was associated with shorter cochlear duct length, and different types of electrodes were used in both groups.

Tuning the electrochemical properties of carbon-based supercapacitors by composite preparation and cell asymmetries

The development of faster, safer and higher performance solid-state energy storage devices has motivated scientists to explore various strategies to obtain more efficient systems. In this work we evaluated the influence of different carbon material electrodes with a gel polymer electrolyte on the electrochemical properties of solid-state supercapacitors. The gel polymer electrolyte exhibited remarkable adhesive characteristics which allowed a good adherability and wettability of the gel electrolyte on the surfaces of all electrodes tested. Four types of supercapacitors were prepared and the influence of different types of electrodes and their combinations on the properties of supercapacitor was evaluated using electrochemical impedance spectroscopy, cyclic voltammetry and the galvanostatic charge/discharge technique that allows synchronous measurements of the cell voltage and the potential of the positive and negative electrodes. The asymmetric device with rGO (reduced graphene oxide) working on the negative electrode and f-MWCNT (acid functionalized multiwalled carbon nanotubes) on the positive electrode showed the best retention capacity for all studied properties (capacitance, energy density and power) after 2000 charge and discharge cycles. Flexible supercapacitor was also prepared, and various electrochemical parameters of the device were studied as a function of bending. We do not observe significant changes in its electrochemical properties after bending.

Unexpected formation of hexahydroxanthenediones by electrochemical synthesis in deep eutectic solvents

The current study reports the unexpected formation of xanthene-1,8-diones upon attempt to perform Biginelli reaction by reacting cyclohexanedione, thiourea and different aldehydes under electrochemical conditions in either ethanol or deep eutectic solvents and utilizing Amberlyst-15® as a heterogeneous acidic catalyst. The Biginelli reaction product; hexahydroquinazoline-5-one, was not observed even upon using varying amounts of catalysts, different reaction times, different types of electrodes, and different types of substituted benzaldehydes. The mechanism of formation of xanthene-1,8-dione was followed up by cyclic voltammetry.

Selection of Electrode Material for Inconel 617/P92 Steel SMAW Dissimilar Welds

Abstract The present work aimed to investigate the microstructure and mechanical properties of the dissimilar shielded metal arc welded (SMAW) joint of Alloy 617 and P92 steel for advanced ultrasupercritical boilers. The SMAW joint was produced using three different types of electrodes, namely, ENiCrFe-3, ENiCrMo-3, and ENiCrCoMo-1. During microstructural observation of the welded joints, no possible cracking was detected in the weldments. The dissimilar metal welds (DMWs) obtained using the ENiCrCoMo-1 electrode showed the maximum tensile strength, while the minimum was obtained for the ENiCrFe-3 electrode. Among all the electrodes, the ENiCrFe-3 electrode exhibited the maximum impact toughness, while the minimum was obtained for ENiCrCoMo-1 electrodes. Based on microstructure and mechanical characterization, the ENiCrFe-3 electrode was selected as the best one among all to produce the DMW of Alloy 617 and P92 steel.

Which is the main factor for improving the performance of the Graphene/MXene hybrid electrode: Ionic number, ionic distribution or ionic configuration?

The Graphene/MXene hybrid, which has been proved by many studies for improving the re-stacking of MXene material, has been widely used as electrode material for supercapacitors. However, there are few reports about the energy storage mechanism of its electrical double layer (EDL), and especially the electrolyte is ionic liquids (ILs) in the electrochemical energy storage system. In this work, the molecular dynamics (MD) simulation was used to study the energy storage performance of three different types of electrodes using imidazolium-based ILs as electrolyte. It is found that compared with MXene material electrode, when the Graphene/MXene composite material is used as the cathode, the energy of the system increase after charging. Moreover, it is interesting to find that the improvement of the energy storage effect does not come from the change of the number of ions between the plates, but from the distribution variation of the imidazolium cations in two different configurations of ‘vertical’ and ‘parallel’ on the different electrode materials surface. At the same time, the dynamic distribution of anions will have a negative impact on the overall energy storage performance of the cathode, and the Graphene materials will aggravate this impact, but the increased layer distance after the Graphene and MXene composite can alleviate this impact. We believe the research is helpful to provide new insights into the design and selection of ionic liquid electrolyte and the application of electrode materials.

A case for hybrid BCIs: combining optical and electrical modalities improves accuracy.

Near-infrared spectroscopy (NIRS) is a promising research tool that found its way into the field of brain-computer interfacing (BCI). BCI is crucially dependent on maximized usability thus demanding lightweight, compact, and low-cost hardware. We designed, built, and validated a hybrid BCI system incorporating one optical and two electrical modalities ameliorating usability issues. The novel hardware consisted of a NIRS device integrated with an electroencephalography (EEG) system that used two different types of electrodes: Regular gelled gold disk electrodes and tri-polar concentric ring electrodes (TCRE). BCI experiments with 16 volunteers implemented a two-dimensional motor imagery paradigm in off- and online sessions. Various non-canonical signal processing methods were used to extract and classify useful features from EEG, tEEG (EEG through TCRE electrodes), and NIRS. Our analysis demonstrated evidence of improvement in classification accuracy when using the TCRE electrodes compared to disk electrodes and the NIRS system. Based on our synchronous hybrid recording system, we could show that the combination of NIRS-EEG-tEEG performed significantly better than either single modality only.

Performance of Sediment Microbial Fuel Cells in Generating Electricity using Fish Wastewater and Shrimp Wastewater as a Nutrient and Their Effect on Waste Quality

Sediment Microbial Fuel Cell (MFC) is a technology that can convert chemical energy into electrical energy through the process of nutrient degradation by microbes. Sediment taken from the bottom of shrimp ponds was added as a source of microbes, while fish and shrimp wastewater were used as a source of nutrients for microbes. This study aims to measure the performance of the SMFC system on fish effluent and shrimp effluent to produce bio-electricity while reducing the waste load. The research method was experimental laboratories. The treatment given was the different types of electrodes, namely zinc-copper and aluminum-copper. In addition, 0.2 M KMnO4 electrolyte solution was used. This study consisted of four stages: the manufacture of nutrients from fish and shrimp wastewater, the manufacture of a dual chamber MFC bioreactor, the measurement of electrical values, and the analysis of waste quality. Experiments were carried out for 30 days by measuring electricity every 24 hours. The average value of electricity generated in the nutrients of fish wastewater with Zn/Cu electrodes was 0.705 V and Al/Cu was 0.472 V. Meanwhile, the average value of electricity in shrimp wastewater nutrients with Zn/Cu electrodes was 0.630 V and Al/Cu was 0.625 V. The number of colonies after adding sediment in the shrimp wastewater sample were 8.9 x 106 CFU/mL, the fish wastewater sample was 9.5 x 106 CFU/mL. It indicates the presence of microorganisms that play a role in the SMFC system

Electrical contact effects of flexible self-supporting DNA thin films for storage devices

The development of flexible DNA thin films embedded with diverse functional nanomaterials might be beneficial for electronic devices and biosensors. In this work, we fabricated two different types of electrodes (i.e. metal paste spotted electrodes and metal layer electrodes) on flexible drug- and dye-embedded DNA thin films to examine their electrical and capacitance properties for conduction and energy storage, respectively. Enhanced current and reduced capacitance of drug-embedded DNA thin films compared with pristine DNA with Ag paste electrodes were observed due to the intrinsic characteristics of the drugs. We used the electron-beam deposition process to fabricate relatively large-area metal-coated (e.g. Au and Al) electrodes, which ensures the creation of metal layers on both sides of the flexible thin films while improving metal contact. There was a significant current increase in DNA thin films with metal layer electrodes compared with DNA thin films with Ag paste electrodes. Furthermore, capacitances measured from Au/DNA/Au and Al/DNA/Al capacitors were relatively more stable than from Ag paste DNA thin films. The physical properties of our samples might be easily controlled by manipulating functional nanomaterials in DNA thin films and various types of metal layer electrodes. Our self-supporting DNA thin films with integrated nanomaterials and durable metal layer electrodes might be employed in flexible electronic devices such as nanogenerators, skin electronics and biosensors in the future.

Studi Pemanfaatan Limbah Cair Ikan dan Udang sebagai Substrat dalam Produksi Listrik pada Sistem Microbial Fuel Cell (MFC)

Microbial fuel cell (MFC) is a technology that utilizes bacteria in organic medium that can convert chemical energy into electrical energy. This technology can be used to treat fishery waste and shrimp waste which is rich in organic matter. This study aimed to measure the performance of the MFC system on fishery wastewater and shrimp wastewater as a means of producing bio-electricity while reducing the waste load. This study used different types of electrodes, including zinc, aluminum, copper, and carbon graphite. This technology used 0.2 M KMNO4 electrolyte solution. The research method includes three stages; production of fishery wastewater and shrimp wastewater, assembly of a dual chamber MFC bioreactor, and measurement of waste electrical energy produced. The value of electricity production with the highest average in fishery wastewater was obtained by adding electrolyte solution to the Zn/Cu electrode during 117 hours of observation were 6.86 mA with a potential difference of 1.469 V meanwhile in shrimp wastewater was obtained by adding electrolyte solution to the Al/Cu electrode were 4.38 mA with a potential difference of 1.335 V.This study can be concluded that higher electricity production is obtained from the utilization of fish wastewater using Zn/Cu electrode.

Ultrathin, all-organic, fabric-based ferroelectret loudspeaker for wearable electronics.

All-organic, flexible, and body-compatible loudspeakers have become increasingly attractive for wearable electronics. Due to their remarkable piezoelectric response, ferroelectrets are suitable for loudspeakers. Two distinct kinds ofultrathin ferroelectrets, including cellular polypropylene films and expanded polytetrafluoroethylene (ePTFE) films, were combined with three different types of electrodes ((Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS))-coated fabrics, PEDOT:PSS direct coating, and sputter-coated Au/Pd) for study regarding their frequency-dependent sound intensity and radiation directivity. Among the loudspeakers investigated, the all-fabric loudspeakers with ePTFE ferroelectret and PEDOT:PSS-coated spandex electrodes have a higher frequency dependency. Loudspeakers equipped with PEDOT:PSS-coated spandex electrodes are less angle dependent compared to other loudspeakers evaluated. Moreover, the soft loudspeaker constituted of an all-organic FEP(fluorinated-ethylene-propylene)-ePTFE-based ferroelectret and PEDOT:PSS-coated fabrics presented in this paper is easy to integrate with clothes and has a higher thermal stability. It is naturally compatible with the human body and a competitive candidate for future developments of all-organic loudspeakers for wearable electronic systems.

Probing the Effects of Electrode Composition and Morphology on the Effectiveness of Silicon Oxide Overlayers to Enhance Selective Oxygen Evolution in the Presence of Chloride Ions.

Seawater electrolysis offers significant logistical advantages over freshwater electrolysis but suffers from a fundamental selectivity problem at the anode. To prevent the evolution of toxic chlorine alongside the evolution of oxygen, a promising approach is the use of electrochemically inert overlayers. Such thin films can exert a perm-selective effect, allowing the transport of water and oxygen between the bulk electrolyte and the electrocatalytic buried interface while suppressing the transport of chloride ions. In this work, we investigate thin (5-20 nm) overlayer films composed of amorphous silicon oxide (SiO x ) and their application to suppressing the chlorine evolution reaction (CER) in favor of the oxygen evolution reaction (OER) during acidic saltwater electrolysis on three different types of electrodes. While SiO x overlayers are seen to be an effective barrier against the CER on well-defined, smooth Pt thin films, decreasing the CER activity roughly 20-fold, this ability has not been previously explored on Ir-based catalysts with a higher surface area relevant to industrial applications. On amorphous iridium oxide electrodes, the selectivity toward the CER versus the OER was marginally reduced from ∼98 to ∼94%, which was attributed to the higher abundance of defects in overlayers deposited on the rougher electrode. On the other hand, Ir-based anodes consisting of thick mixed metal oxide films supported on Ti showed a significant decrease in CER selectivity, from ∼100 to ∼50%, although this came at the cost of reduced activity toward the OER. These results show that the morphology and composition of the underlying electrode play important roles in the effectiveness of the selective overlayers and provide guidance for further development of high-surface-area OER-selective anodes.