Pub Date : 2024-09-08DOI: 10.1149/1945-7111/ad7408
Junam Kwon and Kenji Amaya
In this study, a new framework integrates simulations and flow cell experimentation to quantitatively understand the mechanism of chemical treatment reactions. Using this framework, the mechanisms of etching reactions induced by weak and strong acids were specifically investigated. A flow cell system experiment was developed for the etching experiment. Two acids (HNO3 and HF) were used, along with HNO3 without electrolytes. Average flow velocities were measured, and the molar flux of Fe2+ ions was determined by sampling the solution passing through the flow cell and measuring the iron content by using inductively coupled plasma. A concentration field simulation of the etching reaction in the flow cell was conducted. The concentration field within the boundary layer was visualized to understand the mechanism of H+ ion supply to the metal surface. In the case of weak acid solutions, H+ ions are primarily supplied by dissociation. In contrast, they were supplied by diffusion in strong acid solutions. A boundary layer formed within 100 μm from the metal surface. The experimental and simulated molar flux of Fe2+ ions were compared. The molar flux attributed to weak acid etching was more than 10 times that attributed to strong acids. The reaction rate constant of the H+ reduction reaction was evaluated through a parameter study. The influence of spectator ions on the etching process was investigated. An experiment was conducted to compare the etching of iron plates using HNO3 solutions with different concentrations of spectator ion. The results confirmed that the higher the concentration of the spectator ion, the greater the etching amount. Numerical analysis revealed that the electric field in the electric migration term acts in a direction that impedes the movement of H+ ions to the metal surface. While it is already known that electric migration inhibits electrode reactions, this study enabled its quantitative visualization and evaluation.
{"title":"Framework Integrated with Flow Cell Experiments and Simulations for Understanding Etching in Chemical Conversion Treatments","authors":"Junam Kwon and Kenji Amaya","doi":"10.1149/1945-7111/ad7408","DOIUrl":"https://doi.org/10.1149/1945-7111/ad7408","url":null,"abstract":"In this study, a new framework integrates simulations and flow cell experimentation to quantitatively understand the mechanism of chemical treatment reactions. Using this framework, the mechanisms of etching reactions induced by weak and strong acids were specifically investigated. A flow cell system experiment was developed for the etching experiment. Two acids (HNO3 and HF) were used, along with HNO3 without electrolytes. Average flow velocities were measured, and the molar flux of Fe2+ ions was determined by sampling the solution passing through the flow cell and measuring the iron content by using inductively coupled plasma. A concentration field simulation of the etching reaction in the flow cell was conducted. The concentration field within the boundary layer was visualized to understand the mechanism of H+ ion supply to the metal surface. In the case of weak acid solutions, H+ ions are primarily supplied by dissociation. In contrast, they were supplied by diffusion in strong acid solutions. A boundary layer formed within 100 μm from the metal surface. The experimental and simulated molar flux of Fe2+ ions were compared. The molar flux attributed to weak acid etching was more than 10 times that attributed to strong acids. The reaction rate constant of the H+ reduction reaction was evaluated through a parameter study. The influence of spectator ions on the etching process was investigated. An experiment was conducted to compare the etching of iron plates using HNO3 solutions with different concentrations of spectator ion. The results confirmed that the higher the concentration of the spectator ion, the greater the etching amount. Numerical analysis revealed that the electric field in the electric migration term acts in a direction that impedes the movement of H+ ions to the metal surface. While it is already known that electric migration inhibits electrode reactions, this study enabled its quantitative visualization and evaluation.","PeriodicalId":17364,"journal":{"name":"Journal of The Electrochemical Society","volume":"183 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142222403","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}
Pub Date : 2024-09-08DOI: 10.1149/1945-7111/ad7532
Mingran Yang, Yingchen Xu, Zhengcha Pang, Chenghan Yang, Jinqiang Huang, Min Zhu and Yiwei Zhang
In electrochemical reduction of carbon dioxide (CO2RR), the design of electrocatalysts with high efficiency and selectivity is very important and challenging. In this paper, a ternary composite consisting of ruthenium dioxide and bismuth metal porphyrin-based organic framework (Bi-TCPP MOF)-derived bismuth trioxide and C skeleton has been proposed (denoted as Bi2O3-RuO2@C). Nanoscale RuO2 and Bi2O3 particles are uniformly distributed on the C skeleton. The precursor bismuth metal porphyrin-based organic framework restricts the localized growth of Bi2O3 in the framework, while the unique, highly-conjugated system anchors the doped RuO2 particles, resulting in a uniform distribution of both active sites and hole-enrichment centers. Meanwhile, the Bi-TCPP MOF-derived carbon skeleton has good electrical conductivity, and the macroporous structure also facilitates the gas transport, which leads to the synthesis of Bi2O3-RuO2@C as an electrocatalyst for CO2RR and exhibits excellent catalytic performance and high selectivity for electrocatalytic carbon dioxide reduction to methane (CO2-CH4). The peak Faraday efficiency of Bi2O3-RuO2@C for catalyzing the reduction of CO2-CH4 can reach 66.95% when the doped RuO2 content is 20%. Importantly, this work opens up new horizons for metal ratio regulation in constructing efficient catalytic systems derived from MOFs.
{"title":"Bismuth Metal Porphyrin Framework Doped RuO2 Derived Bi2O3-RuO2@C Composites for Highly Selective CO2 Electroreduction","authors":"Mingran Yang, Yingchen Xu, Zhengcha Pang, Chenghan Yang, Jinqiang Huang, Min Zhu and Yiwei Zhang","doi":"10.1149/1945-7111/ad7532","DOIUrl":"https://doi.org/10.1149/1945-7111/ad7532","url":null,"abstract":"In electrochemical reduction of carbon dioxide (CO2RR), the design of electrocatalysts with high efficiency and selectivity is very important and challenging. In this paper, a ternary composite consisting of ruthenium dioxide and bismuth metal porphyrin-based organic framework (Bi-TCPP MOF)-derived bismuth trioxide and C skeleton has been proposed (denoted as Bi2O3-RuO2@C). Nanoscale RuO2 and Bi2O3 particles are uniformly distributed on the C skeleton. The precursor bismuth metal porphyrin-based organic framework restricts the localized growth of Bi2O3 in the framework, while the unique, highly-conjugated system anchors the doped RuO2 particles, resulting in a uniform distribution of both active sites and hole-enrichment centers. Meanwhile, the Bi-TCPP MOF-derived carbon skeleton has good electrical conductivity, and the macroporous structure also facilitates the gas transport, which leads to the synthesis of Bi2O3-RuO2@C as an electrocatalyst for CO2RR and exhibits excellent catalytic performance and high selectivity for electrocatalytic carbon dioxide reduction to methane (CO2-CH4). The peak Faraday efficiency of Bi2O3-RuO2@C for catalyzing the reduction of CO2-CH4 can reach 66.95% when the doped RuO2 content is 20%. Importantly, this work opens up new horizons for metal ratio regulation in constructing efficient catalytic systems derived from MOFs.","PeriodicalId":17364,"journal":{"name":"Journal of The Electrochemical Society","volume":"29 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142222404","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}
Pub Date : 2024-09-06DOI: 10.1149/1945-7111/ad7407
O. Horner, D. P. Wilkinson, E. L. Gyenge
Seawater electrolysis suffers from many issues that must be resolved before the technology can be scaled. The corrosive hypochlorite formation at the anode can damage the electrode and other electrolyzer components. Furthermore, hypochlorite is unstable and can decay, particularly when exposed to heat and metal ions, which could lead to erroneously high oxygen evolution reaction (OER) selectivity calculations in catalyst benchmarking experiments, resulting in poor catalyst and electrolyzer component selection. In this study, we used the rotating ring-disc electrode (RRDE) technique for the characterization of IrO2, NiO, Co3O4, RuO2, Pt/C, and PtRu electrocatalysts at near-neutral pH (8.4) in 0.5 M NaCl. The RRDE can overcome the challenge posed by thermocatalytic hypochlorite decay. IrO2 and PtRu were also studied over a range of chloride concentrations from 0.1 to 1 M. Our findings reveal that elevated temperatures (313 and 333 K) are conducive to higher OER selectivity, as the OER faradaic efficiency (FE) on IrO2 increased by 23% at 1.22 V vs SHE when the temperature was increased from 293 to 333 K. Increasing the chloride concentration from 0.1 to 1 M increased the OER current density by 40% and 200% on IrO2 and PtRu, respectively, indicating a synergistic relationship.
海水电解存在许多问题，必须先解决这些问题，才能扩大该技术的规模。阳极上形成的次氯酸盐具有腐蚀性，会损坏电极和其他电解槽部件。此外，次氯酸盐不稳定，特别是在受热和接触金属离子时会发生衰变，这可能导致催化剂基准实验中氧进化反应（OER）选择性计算错误，从而导致催化剂和电解槽组件选择不当。在本研究中，我们采用旋转环盘电极（RRDE）技术，在 0.5 M NaCl 溶液中以接近中性的 pH 值（8.4）表征了 IrO2、NiO、Co3O4、RuO2、Pt/C 和 PtRu 电催化剂。RRDE 可以克服次氯酸盐热催化衰变带来的挑战。我们的研究结果表明，温度升高（313 和 333 K）有利于提高 OER 的选择性，因为 IrO2 上的 OER 法拉第效率（FE）在 1.将氯化物浓度从 0.1 M 提高到 1 M，IrO2 和 PtRu 上的 OER 电流密度分别提高了 40% 和 200%，这表明两者之间存在协同关系。
{"title":"Selectivity Study of Direct Seawater Electrolyzer Anode Catalysts Using the Rotating Ring-Disc Electrode Method","authors":"O. Horner, D. P. Wilkinson, E. L. Gyenge","doi":"10.1149/1945-7111/ad7407","DOIUrl":"https://doi.org/10.1149/1945-7111/ad7407","url":null,"abstract":"Seawater electrolysis suffers from many issues that must be resolved before the technology can be scaled. The corrosive hypochlorite formation at the anode can damage the electrode and other electrolyzer components. Furthermore, hypochlorite is unstable and can decay, particularly when exposed to heat and metal ions, which could lead to erroneously high oxygen evolution reaction (OER) selectivity calculations in catalyst benchmarking experiments, resulting in poor catalyst and electrolyzer component selection. In this study, we used the rotating ring-disc electrode (RRDE) technique for the characterization of IrO<sub>2</sub>, NiO, Co<sub>3</sub>O<sub>4</sub>, RuO<sub>2</sub>, Pt/C, and PtRu electrocatalysts at near-neutral pH (8.4) in 0.5 M NaCl. The RRDE can overcome the challenge posed by thermocatalytic hypochlorite decay. IrO<sub>2</sub> and PtRu were also studied over a range of chloride concentrations from 0.1 to 1 M. Our findings reveal that elevated temperatures (313 and 333 K) are conducive to higher OER selectivity, as the OER faradaic efficiency (FE) on IrO<sub>2</sub> increased by 23% at 1.22 V vs SHE when the temperature was increased from 293 to 333 K. Increasing the chloride concentration from 0.1 to 1 M increased the OER current density by 40% and 200% on IrO<sub>2</sub> and PtRu, respectively, indicating a synergistic relationship.","PeriodicalId":17364,"journal":{"name":"Journal of The Electrochemical Society","volume":"41 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142222426","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}
Pub Date : 2024-09-06DOI: 10.1149/1945-7111/ad6e1f
Saheli Bhattacharjee, Sovandeb Sen, Susmita Kundu
Vanadium pentoxide (V2O5), associated with both cathodic and anodic coloration, is considered as one of the best electrochromic (EC) materials for energy-saving smart electronics. Here we present the fabrication and detailed mechanism analysis for improving the electrochromic properties of V2O5 incorporated in a reduced graphene oxide (rGO) matrix using a facile wet chemical method. The microstructural study disclosed the formation of prominent V2O5 nanorods embedded in the rGO matrix. The optimized electrochromic film resulted in coloration (tc) and bleaching time (tb) of ∼6.2 and ∼4.8 s, respectively, much faster than the color switching kinetics of the pristine V2O5 sample (tc ∼ 19.4 s, tb ∼ 15.3 s). The more dispersed structure also ensured an approximate 400% enhancement in the optical modulation of EC film and reflected a noticeable improvement in the coloration efficiency (∼347 cm2/C) of V2O5 film. Modification with rGO resulted in an outstanding improvement in the electrochemical redox stability of V2O5 up to 5000 CV cycles with minimum deterioration in the curve area. The formation of nanorod structure was the prime factor for better ion diffusion and thereby facilitating enhanced performance.
{"title":"Robust Dual-Color Electrochromism of Vanadium Oxide Nanorods Embedded on Reduced Graphene Oxide: Unraveling the Mechanism","authors":"Saheli Bhattacharjee, Sovandeb Sen, Susmita Kundu","doi":"10.1149/1945-7111/ad6e1f","DOIUrl":"https://doi.org/10.1149/1945-7111/ad6e1f","url":null,"abstract":"Vanadium pentoxide (V<sub>2</sub>O<sub>5</sub>), associated with both cathodic and anodic coloration, is considered as one of the best electrochromic (EC) materials for energy-saving smart electronics. Here we present the fabrication and detailed mechanism analysis for improving the electrochromic properties of V<sub>2</sub>O<sub>5</sub> incorporated in a reduced graphene oxide (rGO) matrix using a facile wet chemical method. The microstructural study disclosed the formation of prominent V<sub>2</sub>O<sub>5</sub> nanorods embedded in the rGO matrix. The optimized electrochromic film resulted in coloration (t<sub>c</sub>) and bleaching time (t<sub>b</sub>) of ∼6.2 and ∼4.8 s, respectively, much faster than the color switching kinetics of the pristine V<sub>2</sub>O<sub>5</sub> sample (t<sub>c</sub> ∼ 19.4 s, t<sub>b</sub> ∼ 15.3 s). The more dispersed structure also ensured an approximate 400% enhancement in the optical modulation of EC film and reflected a noticeable improvement in the coloration efficiency (∼347 cm<sup>2</sup>/C) of V<sub>2</sub>O<sub>5</sub> film. Modification with rGO resulted in an outstanding improvement in the electrochemical redox stability of V<sub>2</sub>O<sub>5</sub> up to 5000 CV cycles with minimum deterioration in the curve area. The formation of nanorod structure was the prime factor for better ion diffusion and thereby facilitating enhanced performance.","PeriodicalId":17364,"journal":{"name":"Journal of The Electrochemical Society","volume":"44 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142222458","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}
Pub Date : 2024-09-06DOI: 10.1149/1945-7111/ad749e
Hunter Teel, Taylor R. Garrick, Brian J. Koch, Miguel A. Fernandez, Srikant Srinivasan, Fengkun Wang, Yangbing Zeng, Sirivatch Shimpalee
In this work, a 3D representation of a lithium ion electric vehicle battery cell was created and modeled through the discrete element method (DEM) to capture the porous electrode volume change during cell operation and its effects on electrode strain, porosity changes, and pressure generation for each electrode. This was coupled with a representative volume element approach and the multi species reaction model to quantify the impact of these changes at an electrode level have on the cell level operation. Results on both the electrode level and cell level response were discussed to give insights on how the volume changes contribute to both strain and porosity changes and the potential effects these changes have on the electrochemical response of the generated representative cells. Predictions on the cell level response, particularly for porosity changes which can be difficult to capture experimentally, are essential for the further development of high energy density cells that utilize unique chemistries prone to high levels of volume change such as silicon and silicon oxides. The ability to predict the active material volume change and its nuances will be informative and essential to rapidly develop and design cells for both automotive and grid storage applications.
{"title":"Utilization of DEM Simulations to Quantify Cell Level Thickness and Volume Changes in Large Format Pouch Cells","authors":"Hunter Teel, Taylor R. Garrick, Brian J. Koch, Miguel A. Fernandez, Srikant Srinivasan, Fengkun Wang, Yangbing Zeng, Sirivatch Shimpalee","doi":"10.1149/1945-7111/ad749e","DOIUrl":"https://doi.org/10.1149/1945-7111/ad749e","url":null,"abstract":"In this work, a 3D representation of a lithium ion electric vehicle battery cell was created and modeled through the discrete element method (DEM) to capture the porous electrode volume change during cell operation and its effects on electrode strain, porosity changes, and pressure generation for each electrode. This was coupled with a representative volume element approach and the multi species reaction model to quantify the impact of these changes at an electrode level have on the cell level operation. Results on both the electrode level and cell level response were discussed to give insights on how the volume changes contribute to both strain and porosity changes and the potential effects these changes have on the electrochemical response of the generated representative cells. Predictions on the cell level response, particularly for porosity changes which can be difficult to capture experimentally, are essential for the further development of high energy density cells that utilize unique chemistries prone to high levels of volume change such as silicon and silicon oxides. The ability to predict the active material volume change and its nuances will be informative and essential to rapidly develop and design cells for both automotive and grid storage applications.","PeriodicalId":17364,"journal":{"name":"Journal of The Electrochemical Society","volume":"73 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142222405","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}
Pub Date : 2024-09-05DOI: 10.1149/1945-7111/ad69c5
Zhichen Liu, Ying Li
Thermal runaway monitoring and analysis has become a serious challenge to the safety of lithium-ion battery driven electric equipment. Thermal-runaway monitoring is crucial to avoid the burning and explosion of lithium batteries. This paper proposes a new type of deep neural network, known as whole-feature neural networks (WFNN), for lithium battery thermal-runaway monitoring. The neural networks learn the thermal-runaway patterns of a lithium battery from the measured temperatures, current, and voltages. WFNN is an end-to-end model for thermal-runaway monitoring of lithium batteries. An experiment on thermal-runaway monitoring of lithium batteries was carried out to evaluate the performance of the proposed WFNN. The monitoring accuracy is up to 99.48%, which is higher than those of support vector machine, kernel support vector machine, k-nearest neighbor, and fully-connected neural networks. Moreover, the computation efficiency of WFNN is high enough for real-time thermal-runaway monitoring. As a result, experimental results show that the proposed WFNN is applicable to the thermal-runaway monitoring of lithium batteries.
{"title":"Lithium Battery Thermal-Runaway Monitoring Based on Whole-Feature Neural Networks","authors":"Zhichen Liu, Ying Li","doi":"10.1149/1945-7111/ad69c5","DOIUrl":"https://doi.org/10.1149/1945-7111/ad69c5","url":null,"abstract":"Thermal runaway monitoring and analysis has become a serious challenge to the safety of lithium-ion battery driven electric equipment. Thermal-runaway monitoring is crucial to avoid the burning and explosion of lithium batteries. This paper proposes a new type of deep neural network, known as whole-feature neural networks (WFNN), for lithium battery thermal-runaway monitoring. The neural networks learn the thermal-runaway patterns of a lithium battery from the measured temperatures, current, and voltages. WFNN is an end-to-end model for thermal-runaway monitoring of lithium batteries. An experiment on thermal-runaway monitoring of lithium batteries was carried out to evaluate the performance of the proposed WFNN. The monitoring accuracy is up to 99.48%, which is higher than those of support vector machine, kernel support vector machine, k-nearest neighbor, and fully-connected neural networks. Moreover, the computation efficiency of WFNN is high enough for real-time thermal-runaway monitoring. As a result, experimental results show that the proposed WFNN is applicable to the thermal-runaway monitoring of lithium batteries.","PeriodicalId":17364,"journal":{"name":"Journal of The Electrochemical Society","volume":"62 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142222406","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}
In this work, the effect of electrolysis modes and their parameters on the morphology of the silicon deposits on glassy carbon were studied. In direct current mode it was found that an increase in current density and deposition time changes the morphology of the silicon from a coating to a deposit with a complex surface. Scanning electron microscopy showed that silicon films produced at low current densities and a short deposition time are represented by spherical particles with a diameter of less than 1 μm. The pulse current mode made it possible to increase the cathode density of the deposition current, and the pulse current density to an average of ≈250 mA cm−2 does not lead to the formation of a large amount of dendritic deposit. It was found that a low frequency makes it possible to obtain higher-quality silicon coatings, because when the frequency increases, the coating most often does not cover the entire electrode. The high value of the duty cycle, even at low pulse current densities, always leads to the formation of dendrites. An increase in the total deposition time also leads to an increase in the amount of deposit and the formation of dendrites.
这项工作研究了电解模式及其参数对玻璃碳上硅沉积物形态的影响。研究发现，在直流电模式下，电流密度和沉积时间的增加会改变硅的形态，使其从涂层变为表面复杂的沉积物。扫描电子显微镜显示，在低电流密度和短沉积时间下产生的硅薄膜是直径小于 1 μm 的球形颗粒。脉冲电流模式可以提高沉积电流的阴极密度，平均≈250 mA cm-2的脉冲电流密度不会导致形成大量树枝状沉积物。研究发现，低频率可以获得更高质量的硅涂层，因为当频率增加时，涂层往往无法覆盖整个电极。即使在低脉冲电流密度下，高占空比也会导致树枝状沉积的形成。总沉积时间的增加也会导致沉积量的增加和树枝状晶粒的形成。
{"title":"Electrodeposition of Silicon in the Low-Temperature LiCl-KCl-CsCl-K2SiF6 Melt Under Direct and Pulse Current","authors":"Yulia Parasotchenko, Andrey Suzdaltsev, Yuriy Zaykov","doi":"10.1149/1945-7111/ad73a8","DOIUrl":"https://doi.org/10.1149/1945-7111/ad73a8","url":null,"abstract":"In this work, the effect of electrolysis modes and their parameters on the morphology of the silicon deposits on glassy carbon were studied. In direct current mode it was found that an increase in current density and deposition time changes the morphology of the silicon from a coating to a deposit with a complex surface. Scanning electron microscopy showed that silicon films produced at low current densities and a short deposition time are represented by spherical particles with a diameter of less than 1 μm. The pulse current mode made it possible to increase the cathode density of the deposition current, and the pulse current density to an average of ≈250 mA cm<sup>−2</sup> does not lead to the formation of a large amount of dendritic deposit. It was found that a low frequency makes it possible to obtain higher-quality silicon coatings, because when the frequency increases, the coating most often does not cover the entire electrode. The high value of the duty cycle, even at low pulse current densities, always leads to the formation of dendrites. An increase in the total deposition time also leads to an increase in the amount of deposit and the formation of dendrites.","PeriodicalId":17364,"journal":{"name":"Journal of The Electrochemical Society","volume":"45 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142222409","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}
Porous Al particles with etching pits on their surfaces were prepared by anode etching using a rotating barrel. In this process, Al particles were placed in a barrel with a Pt plate electrode at the bottom. The Al particles were electrified by contacting the Pt electrode in the rotating barrel, and anode etching occurred on the surfaces of the Al particles. The structure of the etching pits formed on the surfaces of the Al particles could be controlled by adjusting the current and electrolysis time during the barrel anode etching. In addition, using an electrolyte solution with a surfactant, it was possible to form etching pits even on the surfaces of Al particles with sizes of 5 μm or less. Porous Mg particles could also be prepared by barrel anode etching using fine Mg particles as the starting material. The porous metal particles obtained using this process have a wide range of potential applications, including sensors, catalyst carriers, and batteries.
{"title":"Fabrication of Porous Metal Particles with Controlled Surface Structures by Barrel Anode Etching","authors":"Takashi Yanagishita, Shota Ueno, Toshiaki Kondo, Hideki Masuda","doi":"10.1149/1945-7111/ad73a9","DOIUrl":"https://doi.org/10.1149/1945-7111/ad73a9","url":null,"abstract":"Porous Al particles with etching pits on their surfaces were prepared by anode etching using a rotating barrel. In this process, Al particles were placed in a barrel with a Pt plate electrode at the bottom. The Al particles were electrified by contacting the Pt electrode in the rotating barrel, and anode etching occurred on the surfaces of the Al particles. The structure of the etching pits formed on the surfaces of the Al particles could be controlled by adjusting the current and electrolysis time during the barrel anode etching. In addition, using an electrolyte solution with a surfactant, it was possible to form etching pits even on the surfaces of Al particles with sizes of 5 μm or less. Porous Mg particles could also be prepared by barrel anode etching using fine Mg particles as the starting material. The porous metal particles obtained using this process have a wide range of potential applications, including sensors, catalyst carriers, and batteries.","PeriodicalId":17364,"journal":{"name":"Journal of The Electrochemical Society","volume":"9 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142222427","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}
We designed a bi-metallic Co-Ni/BTC/4,4′-BiPy metal organic frameworks (MOFs) as an electrode material for the electrochemical detection of epinephrine and nor-epinephrine. The bi-metallic MOFs were synthesized by a solvothermal method. Following this, the bimetallic MOFs were modified with BTC and amine rich 4,4′-BiPy to improve charge transfer kinetics through non-covalent π–π interaction. This modified electrode was employed as a sensing platform for the simultaneous electrochemical detection of epinephrine and nor-epinephrine. The MOFs modified platform exhibited a 10–50 μM linear range with a limit of detection of 0.724 μM ± 0.128 (N = 3) and 0.815 μM ± 0.124 (N = 3), a sensitivity of 0.583 and 0.505 μA μM−1 cm−2 corresponding to epinephrine and nor-epinephrine detection. Finally, the electrochemical sensor was tested in blood and urine samples spiked with known concentrations of epinephrine and nor-epinephrine. Results confirmed the usefulness of the proposed platform for the detection of epinephrine and nor-epinephrine in clinical samples.
{"title":"Bimetallic MOFs-Based Electrodes for the Simultaneous Electrochemical Detection of Epinephrine and Nor-Epinephrine","authors":"Charlin Soosaimanickam, Kathiresan Murugavel, Subbiah Alwarappan","doi":"10.1149/1945-7111/ad6c80","DOIUrl":"https://doi.org/10.1149/1945-7111/ad6c80","url":null,"abstract":"We designed a bi-metallic Co-Ni/BTC/4,4′-BiPy metal organic frameworks (MOFs) as an electrode material for the electrochemical detection of epinephrine and nor-epinephrine. The bi-metallic MOFs were synthesized by a solvothermal method. Following this, the bimetallic MOFs were modified with BTC and amine rich 4,4′-BiPy to improve charge transfer kinetics through non-covalent <italic toggle=\"yes\">π</italic>–<italic toggle=\"yes\">π</italic> interaction. This modified electrode was employed as a sensing platform for the simultaneous electrochemical detection of epinephrine and nor-epinephrine. The MOFs modified platform exhibited a 10–50 μM linear range with a limit of detection of 0.724 μM ± 0.128 (N = 3) and 0.815 μM ± 0.124 (N = 3), a sensitivity of 0.583 and 0.505 μA μM<sup>−1</sup> cm<sup>−2</sup> corresponding to epinephrine and nor-epinephrine detection. Finally, the electrochemical sensor was tested in blood and urine samples spiked with known concentrations of epinephrine and nor-epinephrine. Results confirmed the usefulness of the proposed platform for the detection of epinephrine and nor-epinephrine in clinical samples.","PeriodicalId":17364,"journal":{"name":"Journal of The Electrochemical Society","volume":"10 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142222431","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}
Pub Date : 2024-09-04DOI: 10.1149/1945-7111/ad7326
Ryosuke Jinnouchi
This article introduces the first principles-based grand-canonical formalisms of several representative electronic structure calculation methods in electrochemistry, which are essential for elucidating the atomic-scale mechanisms of electrochemical reactions and discovering the guiding principles for designing advanced materials. While most applications still rely on approximate structures obtained by static calculations at absolute zero, the foundational theories of more rigorous molecular dynamics simulations are also developing. I discuss methods that combine these theories with emerging machine-learning interatomic potentials, suggesting that this approach could pave the way to predict the thermodynamics and kinetics of electrochemical reactions at finite temperatures purely from first principles.
{"title":"Grand-Canonical First Principles-Based Calculations of Electrochemical Reactions","authors":"Ryosuke Jinnouchi","doi":"10.1149/1945-7111/ad7326","DOIUrl":"https://doi.org/10.1149/1945-7111/ad7326","url":null,"abstract":"This article introduces the first principles-based grand-canonical formalisms of several representative electronic structure calculation methods in electrochemistry, which are essential for elucidating the atomic-scale mechanisms of electrochemical reactions and discovering the guiding principles for designing advanced materials. While most applications still rely on approximate structures obtained by static calculations at absolute zero, the foundational theories of more rigorous molecular dynamics simulations are also developing. I discuss methods that combine these theories with emerging machine-learning interatomic potentials, suggesting that this approach could pave the way to predict the thermodynamics and kinetics of electrochemical reactions at finite temperatures purely from first principles.","PeriodicalId":17364,"journal":{"name":"Journal of The Electrochemical Society","volume":"99 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142222425","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}
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