Pub Date : 2024-06-14DOI: 10.1149/1945-7111/ad5871
yaqin Zhou, jingwen Mao, Enhua Wang, H. Zhang
Solid oxide fuel cells (SOFCs) are an effective and sustainable technology for hydrogen utilization. As operating temperatures decrease, metal interconnects and supports are widely employed in SOFCs. It is critical to apply a protective coat on ferritic stainless steel (FSS) to suppress Cr evaporation and element interdiffusion under high temperatures. Electrophoretic deposition (EPD) is a promising approach for depositing metal oxides on FSS substrate. Here, a method based on 3D multi-physical simulation and orthogonal experimental design was proposed to optimize deposition parameters, including applied voltage, deposition time, and electrode distance. The EPD process to deposit Mn1.5Co1.5O4 particles in a suspension of ethanol and isopropanol was simulated and the effects of these three factors on the film thickness and uniformity were analyzed. The results indicate that applied voltage has the greatest impact on deposition thickness, followed by deposition time and electrode distance. Meanwhile, deposition time exhibits a more significant effect on film unevenness than applied voltage. Additionally, the particle-fluid coupling phenomenon was analyzed during the EPD process. In practice, these deposition parameters must be selected appropriately and the deposition time must be controlled to obtain a uniform coating. The proposed method can reduce cost and shorten the design period.
{"title":"Parameters Optimization for Electrophoretic Deposition of Mn1.5Co1.5O4 on Ferritic Stainless Steel Based on Multi-Physical Simulation","authors":"yaqin Zhou, jingwen Mao, Enhua Wang, H. Zhang","doi":"10.1149/1945-7111/ad5871","DOIUrl":"https://doi.org/10.1149/1945-7111/ad5871","url":null,"abstract":"\u0000 Solid oxide fuel cells (SOFCs) are an effective and sustainable technology for hydrogen utilization. As operating temperatures decrease, metal interconnects and supports are widely employed in SOFCs. It is critical to apply a protective coat on ferritic stainless steel (FSS) to suppress Cr evaporation and element interdiffusion under high temperatures. Electrophoretic deposition (EPD) is a promising approach for depositing metal oxides on FSS substrate. Here, a method based on 3D multi-physical simulation and orthogonal experimental design was proposed to optimize deposition parameters, including applied voltage, deposition time, and electrode distance. The EPD process to deposit Mn1.5Co1.5O4 particles in a suspension of ethanol and isopropanol was simulated and the effects of these three factors on the film thickness and uniformity were analyzed. The results indicate that applied voltage has the greatest impact on deposition thickness, followed by deposition time and electrode distance. Meanwhile, deposition time exhibits a more significant effect on film unevenness than applied voltage. Additionally, the particle-fluid coupling phenomenon was analyzed during the EPD process. In practice, these deposition parameters must be selected appropriately and the deposition time must be controlled to obtain a uniform coating. The proposed method can reduce cost and shorten the design period.","PeriodicalId":509718,"journal":{"name":"Journal of The Electrochemical Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141344858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-14DOI: 10.1149/1945-7111/ad586e
Nina Kulik, Nikolay Tkachev, Georgy Starostin, Boris Antonov, Alexander Alexandrovich Chernyshev, Nikolay Shurov, Alexandr Pankratov, Leonid Sitnikov
The electrochemical dealloying of Ag40Pd60 alloys in (LiCl)57(CsCl)26(KCl)17 melt with the addition of 3 mol % silver chloride was studied. Selective anodic dissolution of the alloy was carried out both in the potentiostatic and in galvanostatic regimes at temperatures ranging from 300 to 500°C. The obtained voltammetry characteristics of the initial alloy, chronoamperograms, and chronopotentiogram during the dealloying are presented and discussed. At a temperature near 500°C, the second maximum was observed in the chronoamperograms at two different values of the set potential. The unusual shape of the current curves is due to the superposition of several diffusion processes, which intensities in this case are greater than at lower temperatures. Bi-continuous structures of practically pure palladium with pores and ligaments of sizes ranging from a few to tens of micrometers were obtained in the potentiostatic regime. As the dealloying temperature increased, the sizes of pores and ligaments increased naturally. The same effect was also caused by the increase in applied potential. In the galvanostatic mode similar metallic structures were obtained, but the residual silver content reached 5%, and, in addition, the effects of samples sintering appeared.
{"title":"Fabrication of Microporous Palladium by Selective Anodic Dissolution of Ag-Pd Ag-Pd Alloy in Alkali Chlorides Melt","authors":"Nina Kulik, Nikolay Tkachev, Georgy Starostin, Boris Antonov, Alexander Alexandrovich Chernyshev, Nikolay Shurov, Alexandr Pankratov, Leonid Sitnikov","doi":"10.1149/1945-7111/ad586e","DOIUrl":"https://doi.org/10.1149/1945-7111/ad586e","url":null,"abstract":"\u0000 The electrochemical dealloying of Ag40Pd60 alloys in (LiCl)57(CsCl)26(KCl)17 melt with the addition of 3 mol % silver chloride was studied. Selective anodic dissolution of the alloy was carried out both in the potentiostatic and in galvanostatic regimes at temperatures ranging from 300 to 500°C. The obtained voltammetry characteristics of the initial alloy, chronoamperograms, and chronopotentiogram during the dealloying are presented and discussed. At a temperature near 500°C, the second maximum was observed in the chronoamperograms at two different values of the set potential. The unusual shape of the current curves is due to the superposition of several diffusion processes, which intensities in this case are greater than at lower temperatures. Bi-continuous structures of practically pure palladium with pores and ligaments of sizes ranging from a few to tens of micrometers were obtained in the potentiostatic regime. As the dealloying temperature increased, the sizes of pores and ligaments increased naturally. The same effect was also caused by the increase in applied potential. In the galvanostatic mode similar metallic structures were obtained, but the residual silver content reached 5%, and, in addition, the effects of samples sintering appeared.","PeriodicalId":509718,"journal":{"name":"Journal of The Electrochemical Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141344341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-13DOI: 10.1149/1945-7111/ad57f8
Isakov Andrey, S. Khvostov, Michael Laptev, Anastasia Khudorozhkova, O. Grishenkova, Yuriy Pavlovich Zaikov
Thin silicon films were electrodeposited on glassy carbon (GC) from the KF-KCl (2:1) – 75 mol% KI – 1.5 mol% K2SiF6 melt under potentiostatic condition at 973 K. The synthesized films were single-phase, continuous, dense, and free from unwanted impurities. Neutron transmutation doping (NTD) of the samples was performed in the IVV-2M research reactor (RR) at a thermal neutron flux density of 1.81013 cm−2s−1 for 7.7 h in order to form the 31P isotope dopant. The irradiated samples were studied by scanning electron microscopy with energy-dispersive X-ray spectroscopy, X-ray diffraction, mass spectrometry, and gamma-ray spectrometry. Some excess of the minimum significant specific activity of the irradiated samples was explained by the formation of the 182Ta isotope due to the presence of tantalum traces in the GC substrate. The formation of the 31P isotope by the NTD process was confirmed. The calculated values of 31P concentration and electrical resistivity were 4.91016 cm–3 and 0.15 cm, respectively.
{"title":"Electrodeposition of Thin Silicon Films for Neutron Transmutation Doping","authors":"Isakov Andrey, S. Khvostov, Michael Laptev, Anastasia Khudorozhkova, O. Grishenkova, Yuriy Pavlovich Zaikov","doi":"10.1149/1945-7111/ad57f8","DOIUrl":"https://doi.org/10.1149/1945-7111/ad57f8","url":null,"abstract":"\u0000 Thin silicon films were electrodeposited on glassy carbon (GC) from the KF-KCl (2:1) – 75 mol% KI – 1.5 mol% K2SiF6 melt under potentiostatic condition at 973 K. The synthesized films were single-phase, continuous, dense, and free from unwanted impurities. Neutron transmutation doping (NTD) of the samples was performed in the IVV-2M research reactor (RR) at a thermal neutron flux density of 1.81013 cm−2s−1 for 7.7 h in order to form the 31P isotope dopant. The irradiated samples were studied by scanning electron microscopy with energy-dispersive X-ray spectroscopy, X-ray diffraction, mass spectrometry, and gamma-ray spectrometry. Some excess of the minimum significant specific activity of the irradiated samples was explained by the formation of the 182Ta isotope due to the presence of tantalum traces in the GC substrate. The formation of the 31P isotope by the NTD process was confirmed. The calculated values of 31P concentration and electrical resistivity were 4.91016 cm–3 and 0.15 cm, respectively.","PeriodicalId":509718,"journal":{"name":"Journal of The Electrochemical Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141349793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-13DOI: 10.1149/1945-7111/ad57f9
T. Telmasre, Anthony César Concepción, S. Kolluri, Lubhani Mishra, R. Thiagarajan, Aditya Naveen Matam, Akshay Subramaniam, Taylor R. Garrick, V. Subramanian
Physics-based electrochemical models play a prominent role in the model-based analysis, virtual engineering, and battery management systems (BMS) of lithium-ion and next-generation batteries. Here, we demonstrate the rich physics of phase-field models and convey their potential in BMS applications. Our phase-field model-based optimization framework predicts an impulse-like control profile to reduce capacity degradation. This work was partially inspired by the pulse-charging protocol proposed by Professor Landau in his 2006 work [B. K. Purushothaman and U. Landau, J Electrochem Soc, 153, A533 (2006)]. An open-source framework is shared for predicting the (im)pulse protocol reported.
基于物理的电化学模型在锂离子电池和下一代电池的模型分析、虚拟工程和电池管理系统（BMS）中发挥着重要作用。在此，我们展示了相场模型丰富的物理特性，并传达了其在 BMS 应用中的潜力。我们基于相场模型的优化框架预测了一种类似脉冲的控制曲线，以减少容量衰减。这项工作的部分灵感来自 Landau 教授在其 2006 年著作中提出的脉冲充电协议[B. K. Purushothaman and U. Landau, J Electrochem Soc, 153, A533 (2006)]。我们共享了一个开源框架，用于预测所报告的（非）脉冲协议。
{"title":"Perspective—Moving Next-Generation Phase-Field Models to BMS Applications:A Case Study that Confirms Professor Uzi Landau's Foresight","authors":"T. Telmasre, Anthony César Concepción, S. Kolluri, Lubhani Mishra, R. Thiagarajan, Aditya Naveen Matam, Akshay Subramaniam, Taylor R. Garrick, V. Subramanian","doi":"10.1149/1945-7111/ad57f9","DOIUrl":"https://doi.org/10.1149/1945-7111/ad57f9","url":null,"abstract":"\u0000 Physics-based electrochemical models play a prominent role in the model-based analysis, virtual engineering, and battery management systems (BMS) of lithium-ion and next-generation batteries. Here, we demonstrate the rich physics of phase-field models and convey their potential in BMS applications. Our phase-field model-based optimization framework predicts an impulse-like control profile to reduce capacity degradation. This work was partially inspired by the pulse-charging protocol proposed by Professor Landau in his 2006 work [B. K. Purushothaman and U. Landau, J Electrochem Soc, 153, A533 (2006)]. An open-source framework is shared for predicting the (im)pulse protocol reported.","PeriodicalId":509718,"journal":{"name":"Journal of The Electrochemical Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141348600","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
With the rapid proliferation of electric vehicles, the safety concerns related to lithium-ion batteries are gaining more and more attention. Fault diagnosis is a key approach to reducing the risk of battery failure. However, existing battery management systems (BMS) apply under-sampled voltage signal acquisition, which leads to misdiagnosis and omission of faults. To address this issue, a minor fault early diagnosis method based on static-dynamic compensation voltage data is proposed. First, the voltages of the series-connected cells are asynchronously collected. Then, the collected voltage sequences from various modules are mapped to the voltage sequence of the target battery using the static-dynamic compensating method, which can obtain a new sequence with a significantly higher equivalent sampling frequency. Finally, the sample entropy method is employed to detect minor faults based on the new sequence after compensation. Experimental results reveal that the presented method can increase the sampling frequency by about 8 times. The proposed method can successfully detect minor short circuits and poor connection faults in the battery under different ambient temperatures.
{"title":"Minor Faults Diagnosis for Under-Sampled Lithium-Ion Batteries Based on Static-Dynamic Compensation","authors":"Maab Ali, Jinglun Li, Xin Gu, Xuewen Tao, Ziheng Mao, Yunlong Shang","doi":"10.1149/1945-7111/ad5768","DOIUrl":"https://doi.org/10.1149/1945-7111/ad5768","url":null,"abstract":"\u0000 With the rapid proliferation of electric vehicles, the safety concerns related to lithium-ion batteries are gaining more and more attention. Fault diagnosis is a key approach to reducing the risk of battery failure. However, existing battery management systems (BMS) apply under-sampled voltage signal acquisition, which leads to misdiagnosis and omission of faults. To address this issue, a minor fault early diagnosis method based on static-dynamic compensation voltage data is proposed. First, the voltages of the series-connected cells are asynchronously collected. Then, the collected voltage sequences from various modules are mapped to the voltage sequence of the target battery using the static-dynamic compensating method, which can obtain a new sequence with a significantly higher equivalent sampling frequency. Finally, the sample entropy method is employed to detect minor faults based on the new sequence after compensation. Experimental results reveal that the presented method can increase the sampling frequency by about 8 times. The proposed method can successfully detect minor short circuits and poor connection faults in the battery under different ambient temperatures.","PeriodicalId":509718,"journal":{"name":"Journal of The Electrochemical Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141354259","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-12DOI: 10.1149/1945-7111/ad5767
E. Tredenick, Samuel Wheeler, Ross Drummond, Yige Sun, Stephen R. Duncan, Patrick Grant
Bilayer cathodes comprising two active materials are explored for their ability to improve lithium-ion battery charging performance. Electrodes are manufactured with various arrangements of lithium nickel manganese cobalt oxide Li[Ni0.6Co0.2Mn0.2]O2 (NMC622) and lithium iron phosphate LiFePO4 (LFP) active particles, including in two different discrete sub-layers. We present experimental data on the sensitivity of the electrode C rate performance to the electrode design. To understand the complex bilayer electrode performance, and to identify an optimal design for fast charging, we develop an extension to the Doyle-Fuller-Newman (DFN) model of electrode dynamics that accommodates different active materials in any number of sub-layers, termed the multilayer DFN (M-DFN) model. The M-DFN model is validated against experimental data and then used to explain the performance differences between the electrode arrangements.We show how the different open circuit potential functions of NMC and LFP can be exploited synergistically through electrode design. Manipulating the Li electrolyte concentration increases achievable capacity. Finally the M-DFN model is used to further optimise the best performing bilayer electrode arrangement by adjusting the ratio of the LFP and NMC sub-layer thickness.
{"title":"A Multilayer Doyle-Fuller-Newman Model to Optimise the Rate Performance of Bilayer Cathodes in Li Ion Batteries","authors":"E. Tredenick, Samuel Wheeler, Ross Drummond, Yige Sun, Stephen R. Duncan, Patrick Grant","doi":"10.1149/1945-7111/ad5767","DOIUrl":"https://doi.org/10.1149/1945-7111/ad5767","url":null,"abstract":"\u0000 Bilayer cathodes comprising two active materials are explored for their ability to improve lithium-ion battery charging performance. Electrodes are manufactured with various arrangements of lithium nickel manganese cobalt oxide Li[Ni0.6Co0.2Mn0.2]O2 (NMC622) and lithium iron phosphate LiFePO4 (LFP) active particles, including in two different discrete sub-layers. We present experimental data on the sensitivity of the electrode C rate performance to the electrode design. To understand the complex bilayer electrode performance, and to identify an optimal design for fast charging, we develop an extension to the Doyle-Fuller-Newman (DFN) model of electrode dynamics that accommodates different active materials in any number of sub-layers, termed the multilayer DFN (M-DFN) model. The M-DFN model is validated against experimental data and then used to explain the performance differences between the electrode arrangements.We show how the different open circuit potential functions of NMC and LFP can be exploited synergistically through electrode design. Manipulating the Li electrolyte concentration increases achievable capacity. Finally the M-DFN model is used to further optimise the best performing bilayer electrode arrangement by adjusting the ratio of the LFP and NMC sub-layer thickness.","PeriodicalId":509718,"journal":{"name":"Journal of The Electrochemical Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141354484","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-12DOI: 10.1149/1945-7111/ad5769
D. Turney, Debayon Dutta, Sanjoy Banerjee, Timothy N. Lambert, Nelson S. Bell
Water-in-salt electrolyte (WiSE) promises high-voltage battery technology with low fire risk. Here we assess potassium acetate (KAc) WiSE for Zn ion batteries under commercially relevant conditions. Rotating disc electrode analysis of WiSE degradation and Zn plating/deplating suggest a solid electrolyte interphase (SEI) layer dominates. Butler-Volmer kinetics and Koutecky-Levich mass-transfer are of secondary importance. Measurements of chemical potential reveal that bulk solvation of H2O (in KAc or lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) WiSE) is insignificant compared to SEI blocking. Zinc cycling in KAc WiSE with practical rates (~0.3 to 8.0 mA/cm2) and areal capacities (>20 mAh/cm2) shows dendrites are less prominent than in KOH, but the SEI layer suppresses the electrochemical reaction too much for commercial feasibility. Dilution or convection of the WiSE alleviates the SEI blocking effects. Cu substrate shows good Zn adhesion, but Ti, Sn, and Ni show poor adhesion. Cathodes made with chevrel (Mo6S8) reversibly intercalate Zn2+ to form a novel battery technology, but yield <1.0 V cell voltage. Cathodes made with zinc-containing Prussian blue analogues (ZnHCF or ZnMnHCF) yield a voltage near 2.0 V but appear incompatible with cycling in the present KAc WiSE formulation. Future research directions for KAc WiSE are proposed to focus on SEI dynamics and Prussian blue compatibility
盐包水型电解质（WiSE）有望成为低火灾风险的高压电池技术。在此，我们评估了在商业相关条件下用于锌离子电池的醋酸钾（KAc）WiSE。对 WiSE 降解和锌电镀/脱镀的旋转圆盘电极分析表明，固体电解质相间层（SEI）占主导地位。Butler-Volmer 动力学和 Koutecky-Levich 质量转移是次要的。化学势测量结果表明，与 SEI 阻滞相比，H2O 的大量溶解（在 KAc 或双三氟甲磺酰亚胺锂（LiTFSI）WiSE 中）是微不足道的。在 KAc WiSE 中以实用速率（约 0.3 至 8.0 mA/cm2）和平均容量（大于 20 mAh/cm2）进行锌循环时，树枝状突起没有在 KOH 中那么突出，但 SEI 层对电化学反应的抑制太大，不具备商业可行性。WiSE 的稀释或对流可减轻 SEI 的阻碍作用。铜基板显示出良好的锌附着性，但钛、锡和镍的附着性较差。使用 Chevrel（Mo6S8）制成的阴极可逆地插层 Zn2+，形成了一种新型电池技术，但电池电压小于 1.0 V。用含锌普鲁士蓝类似物（ZnHCF 或 ZnMnHCF）制成的阴极可产生接近 2.0 V 的电压，但似乎与目前 KAc WiSE 配方中的循环不兼容。我们提出了 KAc WiSE 的未来研究方向，重点是 SEI 动力学和普鲁士蓝兼容性。
{"title":"Electrochemical and Cycle Analysis of Water-in-Salt K-Acetate Electrolyte Zn-Ion Batteries Under Commercially-Relevant Conditions","authors":"D. Turney, Debayon Dutta, Sanjoy Banerjee, Timothy N. Lambert, Nelson S. Bell","doi":"10.1149/1945-7111/ad5769","DOIUrl":"https://doi.org/10.1149/1945-7111/ad5769","url":null,"abstract":"\u0000 Water-in-salt electrolyte (WiSE) promises high-voltage battery technology with low fire risk. Here we assess potassium acetate (KAc) WiSE for Zn ion batteries under commercially relevant conditions. Rotating disc electrode analysis of WiSE degradation and Zn plating/deplating suggest a solid electrolyte interphase (SEI) layer dominates. Butler-Volmer kinetics and Koutecky-Levich mass-transfer are of secondary importance. Measurements of chemical potential reveal that bulk solvation of H2O (in KAc or lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) WiSE) is insignificant compared to SEI blocking. Zinc cycling in KAc WiSE with practical rates (~0.3 to 8.0 mA/cm2) and areal capacities (>20 mAh/cm2) shows dendrites are less prominent than in KOH, but the SEI layer suppresses the electrochemical reaction too much for commercial feasibility. Dilution or convection of the WiSE alleviates the SEI blocking effects. Cu substrate shows good Zn adhesion, but Ti, Sn, and Ni show poor adhesion. Cathodes made with chevrel (Mo6S8) reversibly intercalate Zn2+ to form a novel battery technology, but yield <1.0 V cell voltage. Cathodes made with zinc-containing Prussian blue analogues (ZnHCF or ZnMnHCF) yield a voltage near 2.0 V but appear incompatible with cycling in the present KAc WiSE formulation. Future research directions for KAc WiSE are proposed to focus on SEI dynamics and Prussian blue compatibility","PeriodicalId":509718,"journal":{"name":"Journal of The Electrochemical Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141354900","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-12DOI: 10.1149/1945-7111/ad576e
Wenzhan Wu, Pengzhu Lin, Bin Liu, Jianbo Xu, Jing Sun, T. Zhao
In this study, we utilized a platinum ultramicroelectrode (UME) as a model platform for platinum electrocatalysts in acidic electrolytes to study the effects of local mass transfer on the oxygen reduction reaction (ORR), which plays a significant role in fuel cell with reduced pt loading. Finite element simulations showed that the UME exhibits size-dependent ultrathin diffusion layers during the electrochemical process. Submicron-scale UMEs can achieve ultrahigh localized mass transfer, which is unattainable through other experimental techniques. By conducting catalytic experiments under various mass transfer conditions, we found that the mass transfer limiting current is significantly lower than the value predicted by the four-electron process equation. Additionally, the apparent electron transfer number (napp) decreases as the mass transfer coefficient (m0) increases. Furthermore, as m0 increases, the half-wave potential shifts toward more negative values, allowing for the evaluation of the intrinsic activity of the catalysts over a broader potential range. Due to the UME technique's capacity to conveniently control local mass transfer, we foresee its potential application in understanding the effects of chemical microenvironments on complex electrochemical reactions, including ORR and other processes.
{"title":"Effect of High Local Diffusive Mass Transfer on Acidic Oxygen Reduction of Pt Catalysis","authors":"Wenzhan Wu, Pengzhu Lin, Bin Liu, Jianbo Xu, Jing Sun, T. Zhao","doi":"10.1149/1945-7111/ad576e","DOIUrl":"https://doi.org/10.1149/1945-7111/ad576e","url":null,"abstract":"\u0000 In this study, we utilized a platinum ultramicroelectrode (UME) as a model platform for platinum electrocatalysts in acidic electrolytes to study the effects of local mass transfer on the oxygen reduction reaction (ORR), which plays a significant role in fuel cell with reduced pt loading. Finite element simulations showed that the UME exhibits size-dependent ultrathin diffusion layers during the electrochemical process. Submicron-scale UMEs can achieve ultrahigh localized mass transfer, which is unattainable through other experimental techniques. By conducting catalytic experiments under various mass transfer conditions, we found that the mass transfer limiting current is significantly lower than the value predicted by the four-electron process equation. Additionally, the apparent electron transfer number (napp) decreases as the mass transfer coefficient (m0) increases. Furthermore, as m0 increases, the half-wave potential shifts toward more negative values, allowing for the evaluation of the intrinsic activity of the catalysts over a broader potential range. Due to the UME technique's capacity to conveniently control local mass transfer, we foresee its potential application in understanding the effects of chemical microenvironments on complex electrochemical reactions, including ORR and other processes.","PeriodicalId":509718,"journal":{"name":"Journal of The Electrochemical Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141351328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-12DOI: 10.1149/1945-7111/ad576b
Elliot Padgett, Anthony Adesso, Haoran Yu, J. Wrubel, Guido Bender, B. Pivovar, S. Alia
Water contaminants are a common cause of failure for polymer electrolyte membrane (PEM) electrolyzers in the field as well as a confounding factor in research on cell performance and durability. In this study, we investigated the performance impacts of feed water containing representative tap water cations at concentrations ranging from 0.5 – 500 μM, with conductivities spanning from ASTM Type II to tap-water levels. We present multiple diagnostic signatures to help identify the presence of contaminants in PEM electrolysis cells. Through analysis of polarization curves and impedance spectroscopy to understand the origins of performance losses, we found that a switch from the acidic to alkaline hydrogen evolution mechanism is a key factor in contaminated cell behavior. Finally, we demonstrated that this mechanism switching can be harnessed to remove cation contaminants and recover cell performance without the use of an acid wash. We demonstrated near-complete recovery of cells contaminated with sodium and calcium, and partial recovery of a cell contaminated with iron, which was further investigated by post-mortem microscopy. The improved understanding of contaminant impacts from this work can inform development of strategies to mitigate or recover performance losses as well as improve the consistency and rigor of electrolysis research.
水污染是聚合物电解质膜（PEM）电解槽在现场发生故障的常见原因，也是电池性能和耐用性研究中的一个干扰因素。在这项研究中，我们调查了含有代表性自来水阳离子的进水对性能的影响，其浓度范围为 0.5 - 500 μM，电导率从 ASTM II 型到自来水水平不等。我们提出了多种诊断特征，以帮助识别 PEM 电解槽中是否存在污染物。通过分析极化曲线和阻抗光谱来了解性能损失的根源，我们发现从酸性氢进化机制到碱性氢进化机制的转换是电池受污染行为的关键因素。最后，我们证明可以利用这种机制转换来去除阳离子污染物，并在不使用酸洗的情况下恢复电池性能。我们展示了被钠和钙污染的细胞几乎完全恢复，以及被铁污染的细胞的部分恢复。通过这项工作，我们加深了对污染物影响的理解，为制定减轻或恢复性能损失的策略提供了依据，并提高了电解研究的一致性和严谨性。
{"title":"Performance Losses and Current-Driven Recovery from Cation Contaminants in PEM Water Electrolysis","authors":"Elliot Padgett, Anthony Adesso, Haoran Yu, J. Wrubel, Guido Bender, B. Pivovar, S. Alia","doi":"10.1149/1945-7111/ad576b","DOIUrl":"https://doi.org/10.1149/1945-7111/ad576b","url":null,"abstract":"\u0000 Water contaminants are a common cause of failure for polymer electrolyte membrane (PEM) electrolyzers in the field as well as a confounding factor in research on cell performance and durability. In this study, we investigated the performance impacts of feed water containing representative tap water cations at concentrations ranging from 0.5 – 500 μM, with conductivities spanning from ASTM Type II to tap-water levels. We present multiple diagnostic signatures to help identify the presence of contaminants in PEM electrolysis cells. Through analysis of polarization curves and impedance spectroscopy to understand the origins of performance losses, we found that a switch from the acidic to alkaline hydrogen evolution mechanism is a key factor in contaminated cell behavior. Finally, we demonstrated that this mechanism switching can be harnessed to remove cation contaminants and recover cell performance without the use of an acid wash. We demonstrated near-complete recovery of cells contaminated with sodium and calcium, and partial recovery of a cell contaminated with iron, which was further investigated by post-mortem microscopy. The improved understanding of contaminant impacts from this work can inform development of strategies to mitigate or recover performance losses as well as improve the consistency and rigor of electrolysis research.","PeriodicalId":509718,"journal":{"name":"Journal of The Electrochemical Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141353614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-11DOI: 10.1149/1945-7111/ad5708
G. Schmidt, Daniel Niblett, Vahid J. Niasar, I. Neuweiler
Fluid dynamics models complement expensive experiments with limited measurement accuracy that investigate the mass transport in PEM water electrolysis. Here, a first-principle microscale model for oxygen transport is successfully validated that accounts for (1) uncertain transport processes in catalyst layers, (2) numerically challenging capillary-dominated two-phase flow and (3) bubble detachments in channels. We developed algorithms for the stochastic generation of geometries and for the coupling of flow and transport processes. The flow model is based on the volume of fluid method and reproduces experimentally measured pressure drops and bubble velocities within minichannels with a 30% and 20% accuracy, respectively, provided that the capillary number is above 2.1·10-7. At lower capillary numbers, excessive spurious currents occur. Correspondingly, two-phase flow simulations within the porous transport layers are stable at current densities above 0.5 Acm-2 and match operando gas saturation measurements within a 20% margin at relevant locations. The simulated bubble detachments occur at pore throats that agree with porosimetry and microfluidic experiments. The presented model allows explaining and optimizing mass transport processes in channels and porous transport layers. These were found to be negligibly sensitive to transport resistances within the catalyst layer, providing information on boundary conditions for future catalyst layer models.
{"title":"Modeling of Pore-Scale Capillary-Dominated Flow and Bubble Detachment in PEM Water Electrolyzer Anodes Using the Volume of Fluid Method","authors":"G. Schmidt, Daniel Niblett, Vahid J. Niasar, I. Neuweiler","doi":"10.1149/1945-7111/ad5708","DOIUrl":"https://doi.org/10.1149/1945-7111/ad5708","url":null,"abstract":"\u0000 Fluid dynamics models complement expensive experiments with limited measurement accuracy that investigate the mass transport in PEM water electrolysis. Here, a first-principle microscale model for oxygen transport is successfully validated that accounts for (1) uncertain transport processes in catalyst layers, (2) numerically challenging capillary-dominated two-phase flow and (3) bubble detachments in channels. We developed algorithms for the stochastic generation of geometries and for the coupling of flow and transport processes. The flow model is based on the volume of fluid method and reproduces experimentally measured pressure drops and bubble velocities within minichannels with a 30% and 20% accuracy, respectively, provided that the capillary number is above 2.1·10-7. At lower capillary numbers, excessive spurious currents occur. Correspondingly, two-phase flow simulations within the porous transport layers are stable at current densities above 0.5 Acm-2 and match operando gas saturation measurements within a 20% margin at relevant locations. The simulated bubble detachments occur at pore throats that agree with porosimetry and microfluidic experiments. The presented model allows explaining and optimizing mass transport processes in channels and porous transport layers. These were found to be negligibly sensitive to transport resistances within the catalyst layer, providing information on boundary conditions for future catalyst layer models.","PeriodicalId":509718,"journal":{"name":"Journal of The Electrochemical Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141359125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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