Electrochemical science advances最新文献

{"title":"Accurately predicting transport properties of porous fibrous materials by machine learning methods","authors":"Taylr Cawte,&nbsp;Aimy Bazylak","doi":"10.1002/elsa.202100185","DOIUrl":"10.1002/elsa.202100185","url":null,"abstract":"<p>Machine learning algorithms trained on data gathered from stochastically generated gas diffusion layers (GDLs) were used to predict key transport properties that govern effective mass transport behaviour in polymer electrolyte membrane fuel cells. Specifically, we present the largest database in the present literature of stochastically generated fibrous GDL substrates (containing over 2000 unique materials) and the associated structural and transport properties determined via pore network modelling. Seven established machine learning algorithms were trained to predict the effective single-phase permeability (<i>k_sp</i>) and diffusivity (<i>D_sp</i>), and the relative permeability (<i>k_r</i>) and diffusivity (<i>D_r</i>) of the generated materials using well-defined material properties as input features. Gradient boosting regression (GBR), artificial neural network, and support vector regression were the best performing predictors of the single-phase properties, all of which exhibited statistically insignificant differences in error. GBR provided the best prediction accuracy of relative transport properties.</p>","PeriodicalId":93746,"journal":{"name":"Electrochemical science advances","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/elsa.202100185","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43649652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A CuOx/Cu/C electrocatalyst-based gas diffusion electrode for the electroreduction of CO2 with high selectivity to C2H4","authors":"Vimanshu Chanda,&nbsp;João R. C. Junqueira,&nbsp;Nivedita Sikdar,&nbsp;Ignacio Sanjuán,&nbsp;Michael Braun,&nbsp;Stefan Dieckhöfer,&nbsp;Sabine Seisel,&nbsp;Corina Andronescu","doi":"10.1002/elsa.202100200","DOIUrl":"10.1002/elsa.202100200","url":null,"abstract":"<p>Electrochemical conversion of CO₂ (CO₂RR) has received significant attention since it could provide pathways for renewable energy storage to energy-dense chemicals and synthetic fuels. We developed a novel CuO_x/Cu/C type electrocatalyst via pyrolysis, which we used to convert CO₂ at industrially relevantly current densities using gas diffusion electrodes. The influence of the pyrolysis conditions on the electrocatalytic CO₂RR activity and selectivity was evaluated. Optimization of the electrode structure to mitigate electrowetting was done by mixing the catalyst with polytetrafluoroethylene (PTFE). We found that mixing the most active catalyst with PTFE in a mass ratio of 1 to 0.25 substantially increased the formation of C₂H₄ displaying 41% Faradaic efficiency (FE) at –240 mA cm^–2. Prolonged CO₂RR at different current densities shows that the electrode containing 25 wt.% PTFE in the catalyst layer display FE_C2H4&gt; 40% at –280 mA cm^–2 for 2 h.</p>","PeriodicalId":93746,"journal":{"name":"Electrochemical science advances","volume":"3 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/elsa.202100200","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44371887","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"State-of-the-art electrochemistry for the assessment of oxidative stress and integral antioxidant activity of biological environments","authors":"Khiena Z. Brainina,&nbsp;Liliya K. Shpigun","doi":"10.1002/elsa.202100219","DOIUrl":"10.1002/elsa.202100219","url":null,"abstract":"<p>The present review focuses on the interplay between electrochemistry and life, events on the border of electrochemistry-biology-life science, electrochemistry as the basis, and the information source on oxidative stress (OS) or Red/Ox state of biological systems and food to be investigated. Electroanalytical chemistry provides rapid, relatively simple, and sensitive approaches to assess the redox characteristics and antioxidant activity of biologically active compounds in various samples.</p><p>OS is a relatively new physiological response concept, recognized in medicine and biology in the last three decades. This phenomenon is caused by an imbalance between (pro)oxidants and antioxidants in living organisms and it is related to the fundamental redox reactions that underlie health signaling and life processes in general. OS can contribute to many pathological conditions and diseases. In particular, it is recognized that a highly contagious infectious disease, coronavirus disease 2019, is associated with an inflammation process related to OS-induced cellular changes. Recent years have shown a marked increase in electrochemical studies of OS and quantitation of its reductant-oxidant markers (signaling agents), such as reactive oxygen species and antioxidants.</p><p>The goal of this overview is to cover the brief scope of modern electrochemical analysis and sensor devices for monitoring biomarkers of OS and antioxidant status of biological systems. By discussing the great potential of potentiometric and voltammetric methods for human health assessment, it is hoped to bridge between recent electrochemical research and medical diagnostic treatment in the 21st century.</p>","PeriodicalId":93746,"journal":{"name":"Electrochemical science advances","volume":"3 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/elsa.202100219","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47265033","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Photo-electrochromic salt composed by viologen cation and diarylethene anion derivatives","authors":"Hugo Cruz,&nbsp;Noemi Jordão,&nbsp;Sara Santiago,&nbsp;Sandra Gago,&nbsp;Marc Villabona,&nbsp;Jordi Hernando,&nbsp;Gonzalo Guirado,&nbsp;Luís C. Branco","doi":"10.1002/elsa.202100022","DOIUrl":"10.1002/elsa.202100022","url":null,"abstract":"<p>A multi-responsive photo and electrochromic salt based on a viologen derivative ([(C₁₀)₂Bpy]²⁺) as organic cation combined with diarylethene anion ([DTE]²⁻) is synthesized and characterized for the first time. The coloration of this functional salt can be modulated by light and electricity according to further applications. Photochemical determination of the quantum yields in solution for the ring-opening and closure of [(C₁₀)₂Bpy][DTE-COO] ionic liquid have been determined. The electrochemical and electrochromism performance have been also studied in order to evaluate the reduction of bipyridinium cation as well as the oxidation of the DTE anion in its open and closed forms. The possibility of individually addressing the redox state of the anion and cation is seen as a very attractive approach to designing photo-electrochromic devices.</p>","PeriodicalId":93746,"journal":{"name":"Electrochemical science advances","volume":"3 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/elsa.202100022","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41866026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigating the electrowetting of silver-based gas-diffusion electrodes during oxygen reduction reaction with electrochemical and optical methods","authors":"Fabian Bienen,&nbsp;Melanie C. Paulisch,&nbsp;Thorben Mager,&nbsp;Jens Osiewacz,&nbsp;Manigah Nazari,&nbsp;Markus Osenberg,&nbsp;Barbara Ellendorff,&nbsp;Thomas Turek,&nbsp;Ulrich Nieken,&nbsp;Ingo Manke,&nbsp;K. Andreas Friedrich","doi":"10.1002/elsa.202100158","DOIUrl":"10.1002/elsa.202100158","url":null,"abstract":"<p>Porous gas-diffusion electrodes (GDEs) are widely used in electrochemical applications where a gaseous reactant is converted to a target product. Important applications for silver-based GDEs are the chlor-alkali and the CO₂ electrolysis processes in which silver catalyzes the oxygen- or carbon dioxide reduction reaction. The wetting of the porous GDEs is of utmost importance for the achieved performance of the electrode: a completely dry electrode will result in low current densities due to the reduced active surface area while on the other hand, a completely flooded electrode will deteriorate the access of the gaseous reactant. Therefore, we investigated silver-based GDEs for the oxygen reduction reaction with different amounts of the hydrophobic agent polytetrafluoroethylene (PTFE) and analyzed the potential-induced wetting behavior (electrowetting). The electrolyte breakthrough was recorded by a digital microscope and subsequently evaluated via imaging analysis of the observed breached electrolyte droplets. In order to characterize the wetting state during transition to the steady-state, we applied electrochemical impedance spectroscopy measurements and retrieved the double-layer capacitance. Our results indicate that a higher overvoltage facilitates the breakthrough of electrolytes through the gas-diffusion electrode. Surprisingly, a faster breakthrough of electrolyte was observed for electrodes with higher PTFE content. Porometry measurements revealed that the GDE with low PTFE content has a monomodal pore size distribution, whereas electrodes with higher PTFE amount exhibit a bimodal pore size distribution. In GDEs with monomodal pore size distribution the time in which the double layer capacitance is leveling off correlates with the breakthrough time of the electrolyte. In summary, we emphasize that the wetting of GDEs is a complex interplay of the applied potential, electrode composition, and resulting porous structure which requires further advanced measurements and analysis considering the parameters affecting the wetting behavior as a whole.</p>","PeriodicalId":93746,"journal":{"name":"Electrochemical science advances","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/elsa.202100158","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45465263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Adsorption of ionomer and ionic liquid on model Pt catalysts for polymer electrolyte fuel cells","authors":"Kensaku Kodama,&nbsp;Kenta Motobayashi","doi":"10.1002/elsa.202100183","DOIUrl":"10.1002/elsa.202100183","url":null,"abstract":"<p>The adsorption of the perfluoro-sulfonic acid polymer of Nafion and ionic liquid (IL) of 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide on the surface of Pt was investigated via voltammetric analyses, using stepped Pt single-crystal electrodes with (111) terraces and (110) steps, and surface-enhanced infrared absorption spectroscopy (SEIRAS) analyses using a Pt polycrystalline electrode. Sulfonate anion in Nafion was adsorbed on the stepped Pt single-crystal electrodes and suppressed the oxygen reduction reaction (ORR) activity by more than 50%, regardless of the terrace width. The IL molecules were preferentially adsorbed on the step sites through a simple IL coating procedure. The SEIRAS analysis indicated that the IL molecules were stable on the Pt surface throughout potential cycles, where the anionic moieties were in contact with the Pt surface and reoriented depending on the potential. The IL modification prior to Nafion coating mitigated ionomer adsorption on the Pt surface. However, the mitigation effect was not reflected in the ORR activity because water production led to IL desorption during the ORR activity measurement. Accordingly, IL modification is a promising method for improving the performance of Pt catalysts in polymer electrolyte fuel cells; however, further studies to prevent the leaching of IL are required for practical applications of this approach.</p>","PeriodicalId":93746,"journal":{"name":"Electrochemical science advances","volume":"3 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/elsa.202100183","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46890831","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Polarography with non-mercury electrodes: A review","authors":"Ivan Švancara,&nbsp;Tomáš Mikysek,&nbsp;Milan Sýs","doi":"10.1002/elsa.202100205","DOIUrl":"10.1002/elsa.202100205","url":null,"abstract":"<p>This article reviews non-mercury configurations that have hitherto been reported in the literature as the working electrodes applicable in polarographic measurements. The individual types, namely gallium, liquid amalgams, dropping electrolyte, and carbon fluid electrodes, together with a carbon paste-based assembly or even solid disc electrodes with a periodically renewable surface, are presented, discussed, and critically assessed with respect to their potential employment in the present day's electrochemistry and electroanalysis.</p>","PeriodicalId":93746,"journal":{"name":"Electrochemical science advances","volume":"3 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/elsa.202100205","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46414231","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design of tubular high-temperature proton exchange membrane fuel cells (HT-PEM-FCs): Development, challenges, and perspectives","authors":"María Catalina Bermúdez Agudelo,&nbsp;Manfred J. Hampe","doi":"10.1002/elsa.202100193","DOIUrl":"https://doi.org/10.1002/elsa.202100193","url":null,"abstract":"<p>Fuel cells (FCs) have gained a prominent position in recent years within the scientific community and the energy market as an alternative to mitigate the inherent problems in the energy production based on fossil fuels such as the constant reduction of nonrenewable resources, greenhouse gas emissions, and climate change. The versatility of high temperature (HT) proton exchange membrane (PEM) FCs, together with their high efficiency and potentially better performance compared to their counterparts, makes them an excellent candidate to accelerate the transition to more environmental friendly energy sources and processes. In recent years, notable developments in this technology have been reported, focusing on the cell components in a planar arrangement, which is the predominant design for all PEM-FCs. Alternative designs are lagging, even though tubular and conical structures can eventually enhance the power density, decrease sealing areas, and reduce fabrication costs. A lack of information regarding the transition between geometries makes the development and evaluation process tedious and challenging for unconventional architectures. This manuscript describes the development of a novel HT-PEM-FC, pointing out the challenges faced during component manufacturing and the proposed tubular FC perspectives.</p>","PeriodicalId":93746,"journal":{"name":"Electrochemical science advances","volume":"3 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/elsa.202100193","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50141074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Trade-off between energy density and fast-charge capability of lithium-ion batteries: A model-based design study of cells with thick electrodes","authors":"Michael Quarti,&nbsp;Andreas Bayer,&nbsp;Wolfgang G. Bessler","doi":"10.1002/elsa.202100161","DOIUrl":"10.1002/elsa.202100161","url":null,"abstract":"<p>Lithium-ion batteries exhibit a well-known trade-off between energy and power, which is problematic for electric vehicles which require both high energy during discharge (high driving range) and high power during charge (fast-charge capability). We use two commercial lithium-ion cells (high-energy [HE] and high-power) to parameterize and validate physicochemical pseudo-two-dimensional models. In a systematic virtual design study, we vary electrode thicknesses, cell temperature, and the type of charging protocol. We are able to show that low anode potentials during charge, inducing lithium plating and cell aging, can be effectively avoided either by using high temperatures or by using a constant-current/constant-potential/constant-voltage charge protocol which includes a constant anode potential phase. We introduce and quantify a specific charging power as the ratio of discharged energy (at slow discharge) and required charging time (at a fast charge). This value is shown to exhibit a distinct optimum with respect to electrode thickness. At 35°C, the optimum was achieved using an HE electrode design, yielding 23.8 Wh/(min L) volumetric charging power at 15.2 min charging time (10% to 80% state of charge) and 517 Wh/L discharge energy density. By analyzing the various overpotential contributions, we were able to show that electrolyte transport losses are dominantly responsible for the insufficient charge and discharge performance of cells with very thick electrodes.</p>","PeriodicalId":93746,"journal":{"name":"Electrochemical science advances","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/elsa.202100161","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46350883","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electrochemical reduction of quinones in ethaline chosen as an example of deep eutectic solvent","authors":"Fangchen Zhen,&nbsp;Philippe Hapiot","doi":"10.1002/elsa.202100148","DOIUrl":"10.1002/elsa.202100148","url":null,"abstract":"<p>The electrochemical reduction of a series of substituted benzoquinone have been examined in ethaline chosen as an example of ionic deep eutectic solvent. Experiments show the importance of hydrogen-bonding interactions between the quinones or its intermediates and the solvent. The effects are notably visible on the values of reduction potentials that are much more positive in ethaline than in a molecular solvent like acetonitrile and by the small difference between the first and second reduction potentials. The amplitude of the stabilization increases with the donor character of the substituent. Concerning the second reduction, the peak currents are considerably smaller than those of the first reduction and almost disappear at high scan rates (above 50 V s⁻¹). This behavior could be explained considering a chemical step prior to the electron transfer that becomes the limiting step (CE mechanism). As a remarkable feature, the electron transfer kinetics remain fast despite the hydrogen-bonding interactions (<i>k_s</i> = 0.12–0.14 cm s⁻¹).</p>","PeriodicalId":93746,"journal":{"name":"Electrochemical science advances","volume":"3 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/elsa.202100148","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44105842","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}