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In this study, we investigate the use of the ohmic drop compensation method during battery discharges at different rates. Four different types of NMC Li-ion batteries are compared and three 18,650 cells of each type are tested to evaluate the performance dispersion. The cell type that shows significant performance improvement thanks to ohmic drop compensation in this first experimental part is then selected to complete the exploration. A drone-type usage profile is set up and demonstrates without any doubt the interest of using this type of protocol in such usage. Finally, a preliminary aging study is also performed on this type of cells: ohmic drop compensation use has no effect on low-power performance decrease during aging and has a moderate impact on high-power performances.

Hydrogen faces storage/transport challenges, driving ammonia (NH 3 ) as a carbon-free fuel alternative. Direct ammonia fuel cells (DAFCs) exhibit high energy density but require performance optimization. This study employs a 3D model to analyze anode catalytic layer parameters: thicker layers intensify ohmic polarization (degrading mid-high current density performance), while higher porosity (0.4 - 0.5) reduces current density by 4.3% under high loads due to mass transport limits. Results guide DAFC electrode design via structural tuning.

Proton exchange membrane water electrolysis (PEMWE) for hydrogen production possesses wide-ranging and rapid dynamic response capabilities, offering promising applications in the consumption of new energy sources and the dynamic balancing of power grids with a high proportion of renewable energy. The assembly and operating conditions of PEMWE significantly affect its performance. Therefore, thoroughly studying and understanding the influence of PEMWE’s assembly and operating conditions on water electrolysis performance are crucial for enhancing PEMWE’s performance and promoting its applications. In this research, the influence of installation preload torque, feedwater flow rate, and operating temperature on the performance of the electrolyzer, including the electrochemical active specific surface area (ECSA), high-frequency resistance (HFR) and various types of polarizations (including activation polarization, ohmic polarization, and mass transfer polarization) during the operation of the electrolyzer, were detailedly investigated. The results showed that the optimal preload torque and operating temperature for the electrolyzer were 3 Nm and 80°C. Under these conditions, an optimized PEMWE performance would be achieved by ensuring that the feedwater flow rate exceeded the water consumption during electrolysis.

Reducing the electrical energy consumption for formic acid electro-synthesis is indispensable for advancing its industrial implementation. In a conventional CO 2 electrolyzer, most input electrical energy is consumed by the unprofitable anodic oxygen evolution reaction (OER) and ohmic drop. Electrolyzer engineering provides a promising platform to boost electrical energy utilization efficiency beyond catalyst optimization. Herein, we demonstrate a membrane-free CO 2 electrolyzer design that pairs electrochemical CO 2 reduction (CO 2 R) with an all-liquid-phase anodic reaction, enabling dual production of formate at both electrodes with significantly reduced cell voltage. The optimized design exhibits the lowest electrical energy consumption (< 310 kJ mol -1 formate ) at cell voltages below 2.7 V across a current density range of 0.05–0.4 A cm -2 . This cell also maintains stable operation at 2.25 V for 313 h with a < 20 % increase in electrical energy consumption. Systematic techno-economic analysis (TEA) evaluates the economic viability of this design for formic acid electro-synthesis, revealing a potential roadmap towards low-cost formic acid production. This strategy provides guidelines for CO 2 R electrolyzer engineering toward energy-efficient, economically viable production of valuable chemicals. Electrolyzer engineering provides a promising platform to boost energy utilization beyond catalyst optimization. Here, the authors report a membrane-free CO 2 electrolyzer that enables energy-efficient and economically viable electrosynthesis of formic acid.

Polyaniline/hydrothermally treated graphite disk (PANI/HT-G disk) with 3D microporous structure and large surface area is suggested as an effective and inexpensive electrode in the supercapacitor application. The PANI/HT-G disk was easily obtained from uniform mixing of commercial and low-cost azodicarboxamide (ADCA-C 2 H 4 O 2 N 4 ) and graphite powders, pressing beneath optimum pressure pursued by treatment at 250 °C to release various gases (NH 3 , N 2 , CO) originated from ADCA decomposition (creating porous structure with large surface area) and finally electrodeposition of polyaniline onto the previously HT-G disk. The PANI/HT-G disk demonstrated weak ohmic drop and favorite areal capacitance of 1490 mF cm −2 at 2/0 mA cm −2 in aqueous 1.0 M sulfuric acid electrolyte under the three-electrode system. When PANI/HT-G disk was assembled as symmetric supercapacitor disk device with a PVA/H 2 SO 4 gel, the areal capacitance was 232 mF cm −2 at 2/0 mA cm −2 with high operation voltage. The supercapacitor device had an energy density of 93.17, 83.32, 86, 63.96, 60.2, 48.37, and 44.8 mWh cm −2 in the power density of 2.58, 3.22, 3.87, 4.51, 5.16, 5.8, and 6.45 mW cm −2 . It is expected that the strategy introduced in this work could guide designers for scalable fabrication of low-cost supercapacitor disks. Graphical abstract

X‐ray spectroscopy is a valuable technique for the study of many materials systems. Characterizing reactions in situ and operando can reveal complex reaction kinetics, which is crucial to understanding active site composition and reaction mechanisms. In this project, the design, fabrication and testing of an open‐source and easy‐to‐fabricate electrochemical cell for in situ electrochemistry compatible with X‐ray absorption spectroscopy in both transmission and fluorescence modes are accomplished via windows with large opening angles on both the upstream and downstream sides of the cell. Using a hobbyist computer numerical control machine and free 3D CAD software, anyone can make a reliable electrochemical cell using this design. Onion‐like carbon nanoparticles, with a 1:3 iron‐to‐cobalt ratio, were drop‐coated onto carbon paper for testing in situ X‐ray absorption spectroscopy. Cyclic voltammetry of the carbon paper showed the expected behavior, with no increased ohmic drop, even in sandwiched cells. Chronoamperometry was used to apply 0.4 V versus reversible hydrogen electrode, with and without 15 min of oxygen purging to ensure that the electrochemical cell does not provide any artefacts due to gas purging. The XANES and EXAFS spectra showed no differences with and without oxygen, as expected at 0.4 V, without any artefacts due to gas purging. The development of this open‐source electrochemical cell design allows for improved collection of in situ X‐ray absorption spectroscopy data and enables researchers to perform both transmission and fluorescence simultaneously. It additionally addresses key practical considerations including gas purging, reduced ionic resistance and leak prevention. An economical and easy‐to‐fabricate electrochemical cell for in situ X‐ray absorption spectroscopy was developed, fabricated, and used to obtain XANES and EXAFS data for a catalyst for the oxygen reduction reaction. The experiments were run with and without oxygen purging using an attachment that avoids interactions between bubbles and the working electrode, and X‐ray absorption spectroscopy data were obtained under applied potential and with and without gas purging, showing the capabilities of this electrochemical cell for in situ experiments.

The early corrosion development of ultra-low carbon bainitic (ULCB) low alloy steel in NaCl solution was studied by ex situ imaging of corrosion morphology and in situ monitoring of microarea current density and potential, and the corrosion mechanism from initial localized corrosion to uniform corrosion was interpreted. The results indicate that the corrosion development of ULCB steel from initial localized corrosion around inclusions to the uniform corrosion on the whole steel surface is controlled by the galvanic couple effect between different phases resulting from their electrode potential difference in electrolyte solution. The early localized corrosion of steel matrix is initiated and accelerated by the galvanic couple effect between MnS inclusions and steel matrix to form the initial corrosion gaps and the circular corrosion spots around inclusions. The ohmic drop caused by solution resistance influences the acceleration effect of the galvanic couple. With the separation of inclusion from steel matrix, this galvanic couple effect becomes invalid, which results in the expansion from localized corrosion to uniform corrosion. The microgalvanic couple between martensite/residual austenite (M/A) islands and bainite ferrite also accelerates the anodic dissolution of bainite ferrite phase; however, its acceleration corrosion effect is much weaker than that caused by MnS inclusion.

Diffusion is a fundamental irreversible process intervening in the evolution of many out-of-equilibrium systems and is successfully described by Fick’s law obtained from non-equilibrium thermodynamics. Despite this, numerical simulations of solid state electro-deoxidation in the diffusion-controlled regime in molten salt remain elusive. Here, a new model for diffusion controlled three-phase interline (3PI) penetration in a porous cathode during electro-deoxidation is validated against experimental observation. This penetrating 3PI model is applied at high overpotential and benchmarked using the oxygen ionisation TiO 2 (s) + 4e −   → Ti(s) + 2O 2− at the 3PI. The model couples slow diffusive transport and fast oxygen ionisation while assuming a negligible ohmic potential drop in bulk molten CaCl 2 electrolyte. The 14 nm s −1 penetration rate of the 3PI and the order of magnitude of 3PI currents (derived from an exchange current density and cathodic transfer coefficient of 0.32 A cm −2 and 0.01, respectively) in the chronoamperometric data for porous cathodes are in good agreement with experimental observation.

The galvanic corrosion of grounding net in converter station seriously affects its dispersion performance. However, the corrosion potential difference between different metal conductors will aggravate the corrosion speed of the converter station grounding network. In this paper, the variation of corrosion potential difference and corrosion current of dissimilar metals in water medium and soil medium is analyzed by experiments. In the two media, when the circuit resistance is high, the galvanic corrosion is mainly affected by ohmic polarization. Then, CDEGS simulation was used to obtain the change rule of corrosion current under different circuit resistance, and the simulation results are compared with the experimental results. The results show that with the increase of circuit resistance, the corrosion potential difference is basically unchanged, while the corrosion current decreases gradually, and when the circuit resistance increases to a certain margin, the corrosion current decreases gently. When the current density is less than 0.47A/m 2 , ohmic polarization can be used to approximate analyze the galvanic corrosion of dissimilar metal connections.

A comprehensive study concerning the phase formation mechanism and growth/dissolution kinetics of sodium tungsten bronze crystals during the electrolysis of a 0.8Na2WO4–0.2WO3 melt was carried out. The regularities of deposit formation on a Pt(111) working electrode were investigated experimentally using cyclic voltammetry, chronoamperometry, scanning electron microscopy, and X-ray diffraction analysis. Models have been developed to calculate the current response during the formation, growth and dissolution of a two-phase deposit consisting of NaxWO3 and metallic tungsten or two oxide tungsten bronzes with different sodium content. These models consider mass transfer to the electrode and nuclei; chemical and electrochemical reactions with the participation of polytungstate ions, Na+, Na0, and O2−; as well as the ohmic drop effect. The approach was proposed to describe the dissolution of an NaxWO3 crystal with a nonuniform sodium distribution. The fitting of cyclic voltammograms was performed using the Levenberg–Marquardt algorithm. The NaxWO3 formation/growth/dissolution mechanism was determined. Concentration profiles and diffusion coefficients of [WnO3n]−, reaction rate constants, number density of nuclei, and time dependencies of crystal size were calculated. The proposed approaches and models can be used in other systems for the cyclic voltammogram analysis and study of the mechanism and kinetics of electrode processes complicated by phase formation; parallel and sequential electrochemical and chemical reactions; as well as the formation of a deposit characterized by a nonuniform phase and/or chemical composition.