Ankita Pal, Nanda Gopala Krishna, Ravi Shankar A. and John Philip
{"title":"Localized Surface Modification during Alternating Current Scanning Electrochemical Microscopy: Origin and Mechanism","authors":"Ankita Pal, Nanda Gopala Krishna, Ravi Shankar A. and John Philip","doi":"10.1149/1945-7111/ad7890","DOIUrl":"https://doi.org/10.1149/1945-7111/ad7890","url":null,"abstract":"In the current study, we report for the first time the observation of unintended localized surface modification on commercially pure aluminum (Al) during an alternating current scanning electrochemical microscopy (AC-SECM) analysis, its origin, and the probable mechanism responsible for it. Application of an AC perturbation potential (∼100 mV amplitude at ∼100 kHz frequency) to the Platinum ultramicroelectrode (Pt UME), during AC-SECM in acidic, neutral chloride, tap water, and alkaline electrolytes was found to cause surface modification on the scanned region of Al. An increase in the local pH of the electrolyte between the UME and the Al substrate, irrespective of the electrolyte pH (3–11) and UME biasing conditions, led to the local surface modification. The reason for the enhancement of local pH is attributed to the occurrence of higher rates of cathodic reduction reactions than that of anodic oxidation reactions. The reduction of dissolved oxygen/protons/water in the electrolytes led to the generation or consumption of OH−/H+ ions, respectively, and thus increased the pH, whereas the oxidation of Pt UME/Al surfaces decreased the pH with the generation of H+ or consumption of OH− ions. These results contribute significantly to accurately analyzing Al and its alloys using the AC-SECM technique.","PeriodicalId":17364,"journal":{"name":"Journal of The Electrochemical Society","volume":"34 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142269231","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Spatially Resolved Assessment and Analysis of Al-Zn, Mg, and Mg/Al-Zn Metal-Rich Primers Applied to AA 7075-T651 in Full Immersion","authors":"A. Korjenic, E. Romanovskaia and J. R. Scully","doi":"10.1149/1945-7111/ad7535","DOIUrl":"https://doi.org/10.1149/1945-7111/ad7535","url":null,"abstract":"The scanning vibrating electrode technique (SVET) was utilized to monitor localized corrosion and substrate protection of three metal-rich primers (MRP). The ability to suppress localized corrosion and provide widespread cathodic polarization to enable sacrificial anode-based cathodic protection of a AA 7075-T651 substrate with either an aluminum-rich primer (AlRP), magnesium-rich primer (MgRP), or a composite magnesium + aluminum-rich primer (MgAlRP) in a polyamide-based epoxy primer coatings fully immersed in 1 mM NaCl was investigated. Pigments did not activate uniformly in each MRP. The notion of throwing power polarizing the bare substrate and uniform current and potential distributions at scratch sites does not describe the behavior observed. In cases where activation occurred, protection was noticed in the form of suppression of local anodes on bare AA 7075-T651. Local corrosion was suppressed on heterogeneously corroding AA 7075-T651 with strong local anodes and cathodes. Widespread cathodic polarization was absent. The MgRP and MgAlRP were shown to provide superior local corrosion suppression associated with pitting on AA 7075-T651 compared to the AlRP.","PeriodicalId":17364,"journal":{"name":"Journal of The Electrochemical Society","volume":"48 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142263385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wonseok Yang, Suhee Choi, Tae-Hong Park, Sungyeol Choi and Sang-Eun Bae
{"title":"Rotating Disk Electrode Study of Sm(III)/Sm(II) in LiCl-KCl Eutectic Molten Salt","authors":"Wonseok Yang, Suhee Choi, Tae-Hong Park, Sungyeol Choi and Sang-Eun Bae","doi":"10.1149/1945-7111/ad77f5","DOIUrl":"https://doi.org/10.1149/1945-7111/ad77f5","url":null,"abstract":"Understanding the redox reactions of fission products in molten salts is crucial for developing pyroprocessing techniques for used nuclear fuel. A rotating disk electrode is useful for investigating the electrochemical reactions with controlled mass transfer conditions, but its application has been limited in high-temperature corrosive molten salts. This study employs a tungsten (W) rotating disk electrode (RDE) to measure the electrochemical and kinetic properties of the Sm(III)/Sm(II) redox reaction in a LiCl-KCl eutectic molten salt. The properties of the Sm(III)/Sm(II) redox reaction, including diffusion coefficients, exchange current densities, charge transfer coefficients, activation energies, and Tafel slopes, were determined over a temperature range of 723–803 K using limiting currents in linear sweep voltammetry at various rotating speeds and mass transfer-corrected Tafel plots. The kinetic parameters obtained using the rotating disk electrode system can be useful for optimizing the design of pyroprocessing techniques.","PeriodicalId":17364,"journal":{"name":"Journal of The Electrochemical Society","volume":"11 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142263387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Irina-Alina Chera-Anghel, Raluca-Ioana Stefan-van Staden, Catalina Cioates Negut and Jacobus Frederick van Staden
{"title":"A Smartphone Operated Intelligent Stochastic Miniplatform for On-Site Screening of Milk for Fast Determination of Ochratoxin A","authors":"Irina-Alina Chera-Anghel, Raluca-Ioana Stefan-van Staden, Catalina Cioates Negut and Jacobus Frederick van Staden","doi":"10.1149/1945-7111/ad7987","DOIUrl":"https://doi.org/10.1149/1945-7111/ad7987","url":null,"abstract":"Ochratoxine A is a very stable mycotoxin which cannot be destroyed below 250°C. Found in grains, coffee, grapes, wine, milk, and meat, it can produce kidney damage and cancer. Therefore, a smartphone operated intellingent stochastic miniplatform was designed, characterised, and validated for the on-site screening of milk for fast determination of ochratoxine A. (Z)-N-[2-(4-hydroxyphenyl) ethyl]octadec-9-enamide was used as modifier of a gold matrix for a screen printed stochastic sensor used as sensing tool in the design of the miniplatform. A wide linear concentration range (1.0 × 10−15 − 1.0 × 10−7 mol l‒1) and a low limit of quantification of 1 fmol l‒1 were achieved for the assay of ochratoxin A. Recovery values higher than 99.00% were obtained for ochratoxine A, when the miniplatform was used for the screening of cow’s milk and vegetarian milk.","PeriodicalId":17364,"journal":{"name":"Journal of The Electrochemical Society","volume":"19 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142263582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yan Su, Ben Yang, Xinwei Xu, Maosheng Jing, Xinnian Meng and Yongming Tang
{"title":"In Situ PANI Encapsulation of Zinc Powder Enhancing the Corrosion Resistance of Zinc-Rich Epoxy Coatings","authors":"Yan Su, Ben Yang, Xinwei Xu, Maosheng Jing, Xinnian Meng and Yongming Tang","doi":"10.1149/1945-7111/ad7891","DOIUrl":"https://doi.org/10.1149/1945-7111/ad7891","url":null,"abstract":"An approach to encapsulate zinc powder by in situ polymerization of aniline (PANI@Zn) is developed for Zn-rich epoxy coatings (ZRCs). With the application of PANI@Zn composites in the ZRCs, the encapsulated zinc particles are not activated due to the corrosion inhibition of PANI at the early stage of immersion, and physical shielding being mainly responsible for the protection of the steel substrate. At the stage of cathodic protection, the consumption of zinc powder is relatively uniform from the outer layer to the inner layer of the coating PANI@Zn coating, and the utilization rate of zinc powder is higher than that in the coating incorporated by the raw zinc powder. The required amount of zinc powder for achieving the same protective effect as the case of the raw zinc powder is reduced by ca. 20% after the application of the PANI@Zn composites.","PeriodicalId":17364,"journal":{"name":"Journal of The Electrochemical Society","volume":"46 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142263583","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alexander Karger, Simon E. J. O’Kane, Marcel Rogge, Cedric Kirst, Jan P. Singer, Monica Marinescu, Gregory J. Offer and Andreas Jossen
{"title":"Modeling Particle Versus SEI Cracking in Lithium-Ion Battery Degradation: Why Calendar and Cycle Aging Cannot Simply be Added","authors":"Alexander Karger, Simon E. J. O’Kane, Marcel Rogge, Cedric Kirst, Jan P. Singer, Monica Marinescu, Gregory J. Offer and Andreas Jossen","doi":"10.1149/1945-7111/ad76da","DOIUrl":"https://doi.org/10.1149/1945-7111/ad76da","url":null,"abstract":"Degradation models are important tools for understanding and mitigating lithium-ion battery aging, yet a universal model that can predict degradation under all operating conditions remains elusive. One challenge is the coupled influence of calendar and cycle aging phases on degradation mechanisms, such as solid electrolyte interphase (SEI) formation. In this work, we identify and systematically compare three different SEI interaction theories found in the literature, and apply them to experimental degradation data from a commercial lithium-ion cell. In a step-by-step process, and after careful data selection, we show that SEI delamination without any cracking of the active particles, and SEI microcracking, where cycling only affects SEI growth during the cycle itself, are both unlikely candidates. Instead, the results indicate that upon cycling, both the SEI and the active particle crack, and we provide a simple, 4-parameter equation that can predict the particle crack rate. Contrary to the widely-accepted Paris’ law, the particle crack rate decreases with increasing cycles, potentially due to changing intercalation dynamics resulting from the increasing surface-to-volume ratio of the active particles. The proposed model predicts SEI formation accurately at different storage conditions, while simply adding the degradation from pure calendar and cycle aging underestimates the total degradation.","PeriodicalId":17364,"journal":{"name":"Journal of The Electrochemical Society","volume":"94 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142263388","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tim Dörenkamp, Mayank Sabharwal, Federica Marone, Felix N. Büchi, Thomas J. Schmidt and Jens Eller
{"title":"Investigation of Dynamic Water Cluster and Droplet Interactions in Polymer Electrolyte Fuel Cells using Operando X-ray Tomographic Microscopy","authors":"Tim Dörenkamp, Mayank Sabharwal, Federica Marone, Felix N. Büchi, Thomas J. Schmidt and Jens Eller","doi":"10.1149/1945-7111/ad749f","DOIUrl":"https://doi.org/10.1149/1945-7111/ad749f","url":null,"abstract":"Efficient removal of the electrochemically produced water from the gas diffusion layer (GDL) in polymer electrolyte fuel cells is crucial for reducing mass transport losses and improving the efficiency at high current densities. Understanding the relationship between the water percolation through the GDL and droplet formation in the gas channel will allow the design of advanced GDL materials, which provide optimal water management. In this study, a catalyst-coated membrane with 8 individual active areas (0.06 mm2 each) is investigated using operando X-ray tomographic microscopy to study the transient development and interaction of multiple percolating water clusters in a GDL and droplet formation in the channel. The 4D imaging results at a time resolution of 1 Hz showed transient instabilities in the developed percolating water networks at various frequencies associated with break-through and spontaneous water drainage.","PeriodicalId":17364,"journal":{"name":"Journal of The Electrochemical Society","volume":"64 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142263581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ling Ran, Jie Li, Zhong Zou, Bo Zhang, Quanlin Li, Shuai Yang and Hongliang Zhang
{"title":"Fully-Coupled Electric-Thermal-Flow Modeling and Investigation of Dynamic Thermal-Ledge Behavior in Aluminum Electrolysis Cell","authors":"Ling Ran, Jie Li, Zhong Zou, Bo Zhang, Quanlin Li, Shuai Yang and Hongliang Zhang","doi":"10.1149/1945-7111/ad778f","DOIUrl":"https://doi.org/10.1149/1945-7111/ad778f","url":null,"abstract":"Aluminum electrolysis cells (AECs) require effective thermal regulation to operate flexibly alongside renewable energy sources. Prior to implementing thermal regulation strategies, it is essential to predict the dynamic variations in the thermal field and ledge characteristics of a full-scale cell. This study introduces a transient electro-thermal-flow coupling model for a full-scale AEC, aimed at investigating the interactions between ledge distribution and various operational fields, including thermal, electric, and flow fields. The model facilitates the calculation and assessment of the dynamic properties of the ledge and thermal balance under ±15% flexible current variations. Results indicate that during a current increase, ledge melting predominantly occurs in the electrolyte layer, while ledge solidification is primarily observed in the metal layer during a current reduction. Regions with a thicker ledge and faster velocity tend to melt more during current increases and are less likely to return to their original shape and thickness during current reductions, complicating the rapid restoration of thermal equilibrium. To achieve uniform ledge distribution and real-time adaptation to flexible current variations, it is recommended to install distributed cooling devices on the sides of the AEC to enable differential ledge regulation at various locations.","PeriodicalId":17364,"journal":{"name":"Journal of The Electrochemical Society","volume":"30 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142263586","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rankin Shum, Marah Cragun, Tyler Williams and Devin Rappleye
{"title":"Electrochemical Investigation of Moisture Byproducts in Molten Calcium Chloride","authors":"Rankin Shum, Marah Cragun, Tyler Williams and Devin Rappleye","doi":"10.1149/1945-7111/ad76de","DOIUrl":"https://doi.org/10.1149/1945-7111/ad76de","url":null,"abstract":"Residual water in molten CaCl2 reacts to form different byproducts, such as HCl, which can impact the corrosivity of the salt and efficiency of electrochemical operations, such as electrolytic oxide reduction and electrorefining. The ability to detect and quantify these byproducts electrochemically can provide feedback on the efficacy of vacuum drying and other purification methods, as well as the impact of these byproducts on process operations. An electrochemical signal’s association with the production of H2 is verified and characterized using cyclic voltammetry (CV) and residual gas analysis. CV estimated a 2-electron exchange process associated with H2 production. CV detected trace quantities of an oxidized species containing hydrogen in the salt on the order of 10 ppm. Different salt handling methods were compared for their impact on the hydrogen electrochemical signal. It was found that 30 min of exposure of CaCl2 in a beaker to low-humidity air (<20%) had minimal impact on the H2 production signal.","PeriodicalId":17364,"journal":{"name":"Journal of The Electrochemical Society","volume":"3 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142263584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yiwei Sun, Fenjuan Shao, Yuting Luo, Haoxiang Wang, Yuyang He, Liying Sun and Dongpo Xu
{"title":"ZrO2 Nanofiber-Based Molecular Imprinted Electrochemical Sensor for Detection of Ampicillin","authors":"Yiwei Sun, Fenjuan Shao, Yuting Luo, Haoxiang Wang, Yuyang He, Liying Sun and Dongpo Xu","doi":"10.1149/1945-7111/ad7764","DOIUrl":"https://doi.org/10.1149/1945-7111/ad7764","url":null,"abstract":"An efficient molecularly-imprinted electrochemical sensor for the detection of ampicillin was prepared using polypyrrole tetracycline polymer modified with ZrO2 nanofibers. The ZrO2 nanofibers prepared by electrostatic spinning increased the surface area of the electrode with the binding sites of the electropolymerized membrane. The ampicillin sensor with polypyrrole as the functional monomer was able to specifically bind ampicillin molecules and detect ampicillin in various types of samples. In this study, cyclic voltammetry and differential pulse voltammetry were used to evaluate the electrochemical performance of ZrO2-MIP. Under the optimized conditions, the detection limit of this sensor was 0.397 nM, the detection range was 0.5 ∼ 500 nM, and the R2 reached 0.998. It has good selectivity, reproducibility, and stability, and achieves the AMP detection of the milk of the actual samples, which has a good prospect of application.","PeriodicalId":17364,"journal":{"name":"Journal of The Electrochemical Society","volume":"32 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142263585","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}