Pub Date : 2023-08-28DOI: 10.1149/ma2023-01452457mtgabs
Chaoxuan Gu, Yue Qi
Conventional electrochemical organic synthesis uses direct current (DC) condition, where the electrode polarity is not changed during the operation. Unlike DC, alternating current (AC) introduces two more tunable parameters into the potential or current profile: frequency and waveform, allowing new possibilities for modulating reaction efficiency and selectivity. Several very recent AC electrosynthesis examples have shown that the AC can lead to enhanced chemoselectivity that cannot be reproduced by their DC counterparts 1–3 . For instance, Hayashi et al. presented a highly selective and easily scalable Birch-type reduction of heteroarenes by rapid alternating polarity (rAP) waveform 3 . AC voltage transforms the reaction kinetics presumably by affecting the mass transfer of reactive species both in the bulk solution and the electrical double layers (EDL). However, the mechanistic origin of the unique reactivity in AC electrosynthesis is underexplored. Molecular-level details are still in lack to possibly guide the rational design of AC reaction parameters. In this study, we have chosen the rAP heteroarene reduction as the example system and employed classical molecular dynamics (MD) simulations to reveal the liquid structure and dynamics in bulk and interfacial electrolyte. To capture the electrode-electrolyte interfaces, a slab-geometry simulation cell was used, where a 10 nm thick liquid electrolyte is sandwiched between two oppositely charged graphene surfaces. The multicomponent electrolyte was composed of ethanol and tetrahydrofuran (THF) as the co-solvent, [(CH 3 ) 4 N] + [(BF 4 )] - as the salt, and a heteroarene substrate. Based on the charge distribution function statistics, the EDL layer was about 1 nm thick, so if any of the oxygen atom in the ethanol or THF is within 6 Å to the electrode surface, they are considered to be within the EDL. Under both AC and DC, the ethanol to THF ratio was higher than that in the bulk electrolyte due to stronger ion-ethanol attraction. The EDL structure responded to electric field polarity change at different time scales. First, the molecule orientation would flip also within the picosecond time scale after the polarity switch. By tracking the number of molecules in the EDL, we have found that the compositional fluctuation in the EDL converges in about 40 ps. Although it is the ion migration that gets directly affected by the alternating electric field, diffusion of charge-neutral molecules was also found to be accelerated under AC, according to the higher mean squared displacement calculated from the movement of all molecules of each species in the simulation box. This accelerated diffusion spans a larger length and longer time scales. A multi-scale model is proposed to describe both reaction kinetics and liquid structure dynamics simultaneously. References: (1) Rodrigo, S.; Gunasekera, D.; Mahajan, J. P.; Luo, L. Alternating Current Electrolysis for Organic Synthesis. Current Opinion in Electrochemis
{"title":"Structure and Dynamics of the Electrical Double Layer during the Rapid Alternating Polarity Electro-Synthesis","authors":"Chaoxuan Gu, Yue Qi","doi":"10.1149/ma2023-01452457mtgabs","DOIUrl":"https://doi.org/10.1149/ma2023-01452457mtgabs","url":null,"abstract":"Conventional electrochemical organic synthesis uses direct current (DC) condition, where the electrode polarity is not changed during the operation. Unlike DC, alternating current (AC) introduces two more tunable parameters into the potential or current profile: frequency and waveform, allowing new possibilities for modulating reaction efficiency and selectivity. Several very recent AC electrosynthesis examples have shown that the AC can lead to enhanced chemoselectivity that cannot be reproduced by their DC counterparts 1–3 . For instance, Hayashi et al. presented a highly selective and easily scalable Birch-type reduction of heteroarenes by rapid alternating polarity (rAP) waveform 3 . AC voltage transforms the reaction kinetics presumably by affecting the mass transfer of reactive species both in the bulk solution and the electrical double layers (EDL). However, the mechanistic origin of the unique reactivity in AC electrosynthesis is underexplored. Molecular-level details are still in lack to possibly guide the rational design of AC reaction parameters. In this study, we have chosen the rAP heteroarene reduction as the example system and employed classical molecular dynamics (MD) simulations to reveal the liquid structure and dynamics in bulk and interfacial electrolyte. To capture the electrode-electrolyte interfaces, a slab-geometry simulation cell was used, where a 10 nm thick liquid electrolyte is sandwiched between two oppositely charged graphene surfaces. The multicomponent electrolyte was composed of ethanol and tetrahydrofuran (THF) as the co-solvent, [(CH 3 ) 4 N] + [(BF 4 )] - as the salt, and a heteroarene substrate. Based on the charge distribution function statistics, the EDL layer was about 1 nm thick, so if any of the oxygen atom in the ethanol or THF is within 6 Å to the electrode surface, they are considered to be within the EDL. Under both AC and DC, the ethanol to THF ratio was higher than that in the bulk electrolyte due to stronger ion-ethanol attraction. The EDL structure responded to electric field polarity change at different time scales. First, the molecule orientation would flip also within the picosecond time scale after the polarity switch. By tracking the number of molecules in the EDL, we have found that the compositional fluctuation in the EDL converges in about 40 ps. Although it is the ion migration that gets directly affected by the alternating electric field, diffusion of charge-neutral molecules was also found to be accelerated under AC, according to the higher mean squared displacement calculated from the movement of all molecules of each species in the simulation box. This accelerated diffusion spans a larger length and longer time scales. A multi-scale model is proposed to describe both reaction kinetics and liquid structure dynamics simultaneously. References: (1) Rodrigo, S.; Gunasekera, D.; Mahajan, J. P.; Luo, L. Alternating Current Electrolysis for Organic Synthesis. Current Opinion in Electrochemis","PeriodicalId":11461,"journal":{"name":"ECS Meeting Abstracts","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135088778","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 : 2023-08-28DOI: 10.1149/ma2023-0154203mtgabs
Dong Ding
Proton Conducting Solid Oxide Electrolysis Cells (p-SOEC) is an emerging and attractive technology for hydrogen production through water electrolysis at intermediate temperatures. Economically competitive p-SOEC systems have distinct advantages over conventional oxygen-ion conducting ceramic electrochemical cells, but further technology development and widespread market acceptance will require continuous innovation of materials and structures in order to improve cell performance, enhance system lifetime and reduce cost. Herein, we report the advancement of p-SOEC with materials R&D, interface engineering, as well as cell fabrication and manufacturing in INL. We highlight how DOE support through HydroGEN accelerates move up the technology readiness level.
{"title":"Advancement of Proton Conducting Solid Oxide Electrolysis Cells (p-SOEC) for Hydrogen Production at Idaho National Laboratory","authors":"Dong Ding","doi":"10.1149/ma2023-0154203mtgabs","DOIUrl":"https://doi.org/10.1149/ma2023-0154203mtgabs","url":null,"abstract":"Proton Conducting Solid Oxide Electrolysis Cells (p-SOEC) is an emerging and attractive technology for hydrogen production through water electrolysis at intermediate temperatures. Economically competitive p-SOEC systems have distinct advantages over conventional oxygen-ion conducting ceramic electrochemical cells, but further technology development and widespread market acceptance will require continuous innovation of materials and structures in order to improve cell performance, enhance system lifetime and reduce cost. Herein, we report the advancement of p-SOEC with materials R&D, interface engineering, as well as cell fabrication and manufacturing in INL. We highlight how DOE support through HydroGEN accelerates move up the technology readiness level.","PeriodicalId":11461,"journal":{"name":"ECS Meeting Abstracts","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135088780","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 : 2023-08-28DOI: 10.1149/ma2023-01482528mtgabs
Artur Huseinov, Chaminda P Nawarathne, Noe T Alvarez
Detection of hydrogen peroxide (H 2 O 2 ) has practical significance in various fields, including pharmaceutical, clinical and food industries. The enzyme based H 2 O 2 biosensors allow for the detection at lower potentials, thus avoiding possible interference from reducing agents. However, this type of sensors is inherently less stable, difficult to fabricate and more expensive. Due to high electroactive surface area and electrocatalytic properties, gold nanoparticles and their combination with carbon nanotubes (CNTs) are commonly used in H 2 O 2 sensor design. To avoid fabrication inconveniences and improve stability of a H 2 O 2 sensor, we designed a new hybrid material in which CNTs are covalently attached to a gold surface. First, a highly homogeneous nanostructured gold surface was formed on top of the SiO 2 substrate with an intermediate layer of Ti, using E-beam evaporation technique. The average height of the gold nanostructures was 3.9 nm. The gold surface was then electrochemically grafted with aminophenyl groups. Further, plasma-functionalized densified CNT film made from CNT array was attached to the gold surface via amide formation reaction. An introduction of CNTs led to a 40-fold increase in current response. Formation of nanostructured gold surface without actual attachment of nanoparticles to the substrate, as well as covalent bonding of CNTs to the surface, provide a very high stability of the fabricated material, which, in turn, improves the repeatability of measurements. A designed electrode was used for non-enzymatic H 2 O 2 detection. Under optimized parameters of square wave voltammetry and optimum pH, analysis of H 2 O 2 can be performed using 5 independent oxidation peaks. The presence of multiple peaks is due to oxidation of gold, CNTs and H 2 O 2 itself. All peaks increase when H 2 O 2 is added in solution, because of chemical reduction of CNT and gold surfaces, and their consecutive electrochemical oxidation. Using the peak at -0.6 V allows for the H 2 O 2 detection at very low potential, that can minimize interference from various reducing agents. For the -0.6 V peak, the limit of detection was 1.4 mM. Using the peak at -0.05 V allows for much higher sensitivity with the limit of detection of 500 nM. Almost no signal deterioration was observed after 200 measurements, proving high stability of the fabricated electrodes.
{"title":"Detection of H<sub>2</sub>O<sub>2 </sub>using Carbon Nanotubes Covalently Attached to Nanostructured Au Electrode","authors":"Artur Huseinov, Chaminda P Nawarathne, Noe T Alvarez","doi":"10.1149/ma2023-01482528mtgabs","DOIUrl":"https://doi.org/10.1149/ma2023-01482528mtgabs","url":null,"abstract":"Detection of hydrogen peroxide (H 2 O 2 ) has practical significance in various fields, including pharmaceutical, clinical and food industries. The enzyme based H 2 O 2 biosensors allow for the detection at lower potentials, thus avoiding possible interference from reducing agents. However, this type of sensors is inherently less stable, difficult to fabricate and more expensive. Due to high electroactive surface area and electrocatalytic properties, gold nanoparticles and their combination with carbon nanotubes (CNTs) are commonly used in H 2 O 2 sensor design. To avoid fabrication inconveniences and improve stability of a H 2 O 2 sensor, we designed a new hybrid material in which CNTs are covalently attached to a gold surface. First, a highly homogeneous nanostructured gold surface was formed on top of the SiO 2 substrate with an intermediate layer of Ti, using E-beam evaporation technique. The average height of the gold nanostructures was 3.9 nm. The gold surface was then electrochemically grafted with aminophenyl groups. Further, plasma-functionalized densified CNT film made from CNT array was attached to the gold surface via amide formation reaction. An introduction of CNTs led to a 40-fold increase in current response. Formation of nanostructured gold surface without actual attachment of nanoparticles to the substrate, as well as covalent bonding of CNTs to the surface, provide a very high stability of the fabricated material, which, in turn, improves the repeatability of measurements. A designed electrode was used for non-enzymatic H 2 O 2 detection. Under optimized parameters of square wave voltammetry and optimum pH, analysis of H 2 O 2 can be performed using 5 independent oxidation peaks. The presence of multiple peaks is due to oxidation of gold, CNTs and H 2 O 2 itself. All peaks increase when H 2 O 2 is added in solution, because of chemical reduction of CNT and gold surfaces, and their consecutive electrochemical oxidation. Using the peak at -0.6 V allows for the H 2 O 2 detection at very low potential, that can minimize interference from various reducing agents. For the -0.6 V peak, the limit of detection was 1.4 mM. Using the peak at -0.05 V allows for much higher sensitivity with the limit of detection of 500 nM. Almost no signal deterioration was observed after 200 measurements, proving high stability of the fabricated electrodes.","PeriodicalId":11461,"journal":{"name":"ECS Meeting Abstracts","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135088790","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 : 2023-08-28DOI: 10.1149/ma2023-01372155mtgabs
Seunghwan Jo, Woon Bae Park, Docheon Ahn, Kee-Sun Sohn, Ki Hoon Shin, John Hong, Jung Inn Sohn
Hydrogen energy production through the electricity-driven water electrolysis has been broadly studied to deal with growing energy demands and environment pollutions. Oxygen evolution reaction (OER) which is the half anodic reaction of water electrolysis determines overall water electrolysis due to OOH* coordination with high energy barrier. Recently, alternative reaction kinetics detouring sluggish OOH intermediate in OER pathway has been proposed as breakthrough for efficient water electrolysis. That is the strategy which directly conjugates activated lattice oxygen species to form O-O coupling instead of OOH intermediate. However, absence of facile method to realize lattice oxygen activation and structural instability during OER cycles remain as challenge, hindering practical applications of water electrolysis. In this work, metal-oxygen hybridization method has been demonstrated as not only a simple and facile strategy to activate lattice oxygen species but also sustain lattice oxygen mechanism (LOM) during OER cycles at a practical current density (> 1000 mA cm -2 ). Using redox potential difference between bismuth (Bi) and iron (Fe) as driving force, galvanic replacement and Kirkendall effect take place in binary metal system, resulting in heterostructure composed of amorphous BiFe(oxy)hydroxides and molecular bismuth (Bi) metal nanoparticles (BM/BiFeO x H y ) with abundant oxygen non-bonding states. In 1 M KOH solution, the BM/BiFeO x H y electrocatalyst requires low overpotential of 232 and 359 mV at the current densities of 10 and 1,000 mA cm -2 , respectively. Moreover, long-term catalytic stability is demonstrated up to 1,000 hours at a practically high current density of 1,000 mA cm -2 without significant degradation by virtue of the balanced hybridization of Bi/Fe-O. Electrochemical/physicochemical analysis and density functional theory (DFT) calculation reveal that the excellent OER performance and stability of BM/BiFeO x H y electrocatalyst are attributed to the optimized Fe/Bi-O hybridization and resulting heterostructure with increased oxygen non-bonding states.
通过电力驱动的水电解生产氢能源已被广泛研究，以应对日益增长的能源需求和环境污染。析氧反应(OER)是水电解的半阳极反应，由于OOH*具有高能垒的配位，决定了整个水电解过程。近年来，绕过OER途径中迟缓的OOH中间体的替代反应动力学被提出作为高效水电解的突破口。这是直接共轭活化晶格氧形成O-O偶联而代替OOH中间体的策略。然而，缺乏简便的方法来实现OER循环中的晶格氧活化和结构不稳定性仍然是一个挑战，阻碍了水电解的实际应用。在这项工作中，金属氧杂化方法不仅被证明是一种简单易行的激活晶格氧的策略，而且在实际电流密度(>1000毫安厘米-2)。利用铋(Bi)和铁(Fe)之间的氧化还原电位差作为驱动力，在二元金属体系中发生电替换和Kirkendall效应，形成由无定形BiFe(氧)氢氧化物和分子铋(Bi)金属纳米粒子(BM/BiFeO x H y)组成的异质结构，具有丰富的氧非键态。在1 M KOH溶液中，BM/BiFeO x hy电催化剂在电流密度分别为10和1000 mA cm -2时需要232和359 mV的低过电位。此外，由于Bi/Fe-O的平衡杂化，在1,000 mA cm -2的高电流密度下，长期催化稳定性可达1,000小时，而不会显着降解。电化学/物理化学分析和密度泛函理论(DFT)计算表明，BM/BiFeO x hy电催化剂优异的OER性能和稳定性归因于优化的Fe/Bi-O杂化和由此产生的异质结构，增加了氧非键态。
{"title":"Metal-Oxygen Hybridization of Bi/Bife(oxy)Hydroxide for Sustainable Lattice Oxygen Mechanism at High Current Density","authors":"Seunghwan Jo, Woon Bae Park, Docheon Ahn, Kee-Sun Sohn, Ki Hoon Shin, John Hong, Jung Inn Sohn","doi":"10.1149/ma2023-01372155mtgabs","DOIUrl":"https://doi.org/10.1149/ma2023-01372155mtgabs","url":null,"abstract":"Hydrogen energy production through the electricity-driven water electrolysis has been broadly studied to deal with growing energy demands and environment pollutions. Oxygen evolution reaction (OER) which is the half anodic reaction of water electrolysis determines overall water electrolysis due to OOH* coordination with high energy barrier. Recently, alternative reaction kinetics detouring sluggish OOH intermediate in OER pathway has been proposed as breakthrough for efficient water electrolysis. That is the strategy which directly conjugates activated lattice oxygen species to form O-O coupling instead of OOH intermediate. However, absence of facile method to realize lattice oxygen activation and structural instability during OER cycles remain as challenge, hindering practical applications of water electrolysis. In this work, metal-oxygen hybridization method has been demonstrated as not only a simple and facile strategy to activate lattice oxygen species but also sustain lattice oxygen mechanism (LOM) during OER cycles at a practical current density (> 1000 mA cm -2 ). Using redox potential difference between bismuth (Bi) and iron (Fe) as driving force, galvanic replacement and Kirkendall effect take place in binary metal system, resulting in heterostructure composed of amorphous BiFe(oxy)hydroxides and molecular bismuth (Bi) metal nanoparticles (BM/BiFeO x H y ) with abundant oxygen non-bonding states. In 1 M KOH solution, the BM/BiFeO x H y electrocatalyst requires low overpotential of 232 and 359 mV at the current densities of 10 and 1,000 mA cm -2 , respectively. Moreover, long-term catalytic stability is demonstrated up to 1,000 hours at a practically high current density of 1,000 mA cm -2 without significant degradation by virtue of the balanced hybridization of Bi/Fe-O. Electrochemical/physicochemical analysis and density functional theory (DFT) calculation reveal that the excellent OER performance and stability of BM/BiFeO x H y electrocatalyst are attributed to the optimized Fe/Bi-O hybridization and resulting heterostructure with increased oxygen non-bonding states.","PeriodicalId":11461,"journal":{"name":"ECS Meeting Abstracts","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135088791","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 : 2023-08-28DOI: 10.1149/ma2023-01382222mtgabs
Marek Janssen, Jochen Klein, Alexandra Dworzak, Sonja Blaseio, Mehtap Oezaslan
PtCo alloy nanoparticles (NPs) are widely used as highly active oxygen reduction reaction (ORR) catalysts for polymer electrolyte membrane fuel cells (PEMFCs). Despite large efforts, the critical relationships between structure, composition and ORR performance of catalyst materials are not fully understood to date. In this study, we prepared two PtCo alloy NP catalysts with an atomic ratio of 1:1 using wet-impregnation route by varying the annealing parameters under reductive conditions. The as-prepared PtCo alloy catalysts were structurally characterized using ex-situ HR-TEM, EDX, XRD, and EXAFS. We show that the annealing temperature and holding time affect the particle size, composition and homogeneity of the PtCo NPs. With higher annealing temperature and longer holding time, the particle size grows from 3.1 ± 0.7 nm (400 °C, 4 h) to 4.4 ± 0.6 nm (800 °C, 6 h) and simultaneously, the alloy formation within the NPs improves. After electrochemical activation in 0.1 M HClO 4 , the electrochemically active Pt surface area (ECSA) for activated PtCo T400 (65 ± 8 m 2 g Pt -1 ) is slightly lower than that for pure Pt/C (70 ± 11 m 2 g Pt -1 ), but significantly higher than that for the activated PtCo T800 (50 ± 4 m 2 g Pt -1 ). However, the activated PtCo T800 shows the highest ORR mass activity (0.56 ± 0.14 A mg Pt -1 at 0.9 V RHE, iR-free ) than the activated PtCo T400 (0.43 ± 0.03 A mg Pt -1 ) and Pt/C (0.24 ± 0.04 A mg Pt -1 ). Altogether, we provide deeper understanding of the structure - composition - ORR activity relationships for two differently annealed PtCo alloy catalyst materials.
PtCo纳米颗粒被广泛用作聚合物电解质膜燃料电池(pemfc)的高活性氧还原反应(ORR)催化剂。尽管付出了巨大的努力，但迄今为止，催化剂材料的结构、组成和ORR性能之间的关键关系仍未被完全理解。本研究在还原条件下，通过改变退火参数，采用湿浸渍的方法制备了两种原子比为1:1的PtCo合金NP催化剂。采用原位HR-TEM、EDX、XRD和EXAFS对制备的PtCo合金催化剂进行了结构表征。结果表明，退火温度和保温时间影响了PtCo NPs的粒径、组成和均匀性。随着退火温度的升高和保温时间的延长，纳米粒子的粒径从3.1±0.7 nm(400℃，4 h)增大到4.4±0.6 nm(800℃，6 h)，同时纳米粒子内部的合金形成也有所改善。在0.1 M HClO 4中进行电化学活化后，活化PtCo T400(65±8 M 2 g Pt -1)的电化学活性Pt表面积(ECSA)略低于纯Pt/C(70±11 M 2 g Pt -1)，但显著高于活化PtCo T800(50±4 M 2 g Pt -1)。然而，活化的PtCo T800表现出最高的ORR质量活性(0.56±0.14 A mg Pt -1，在0.9 V RHE，无ir)，高于活化的PtCo T400(0.43±0.03 A mg Pt -1)和Pt/C(0.24±0.04 A mg Pt -1)。总之，我们对两种不同退火PtCo合金催化剂材料的结构-组成- ORR活性关系有了更深入的了解。
{"title":"Insights into the Structure - Composition - Activity Relationship of PtCo Alloy Nanoparticles towards Oxygen Reduction Reaction (ORR)","authors":"Marek Janssen, Jochen Klein, Alexandra Dworzak, Sonja Blaseio, Mehtap Oezaslan","doi":"10.1149/ma2023-01382222mtgabs","DOIUrl":"https://doi.org/10.1149/ma2023-01382222mtgabs","url":null,"abstract":"PtCo alloy nanoparticles (NPs) are widely used as highly active oxygen reduction reaction (ORR) catalysts for polymer electrolyte membrane fuel cells (PEMFCs). Despite large efforts, the critical relationships between structure, composition and ORR performance of catalyst materials are not fully understood to date. In this study, we prepared two PtCo alloy NP catalysts with an atomic ratio of 1:1 using wet-impregnation route by varying the annealing parameters under reductive conditions. The as-prepared PtCo alloy catalysts were structurally characterized using ex-situ HR-TEM, EDX, XRD, and EXAFS. We show that the annealing temperature and holding time affect the particle size, composition and homogeneity of the PtCo NPs. With higher annealing temperature and longer holding time, the particle size grows from 3.1 ± 0.7 nm (400 °C, 4 h) to 4.4 ± 0.6 nm (800 °C, 6 h) and simultaneously, the alloy formation within the NPs improves. After electrochemical activation in 0.1 M HClO 4 , the electrochemically active Pt surface area (ECSA) for activated PtCo T400 (65 ± 8 m 2 g Pt -1 ) is slightly lower than that for pure Pt/C (70 ± 11 m 2 g Pt -1 ), but significantly higher than that for the activated PtCo T800 (50 ± 4 m 2 g Pt -1 ). However, the activated PtCo T800 shows the highest ORR mass activity (0.56 ± 0.14 A mg Pt -1 at 0.9 V RHE, iR-free ) than the activated PtCo T400 (0.43 ± 0.03 A mg Pt -1 ) and Pt/C (0.24 ± 0.04 A mg Pt -1 ). Altogether, we provide deeper understanding of the structure - composition - ORR activity relationships for two differently annealed PtCo alloy catalyst materials.","PeriodicalId":11461,"journal":{"name":"ECS Meeting Abstracts","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135088795","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 : 2023-08-28DOI: 10.1149/ma2023-0154210mtgabs
Stephan Sarner, Norbert H. Menzler, Andrea Hilgers, Olivier Guillon
Fuel Cell and Hydrogen (FCH) applications will become crucial to enable the transition towards decarbonatization and meet the EU's zero net greenhouse gas emission targets to be achieved by 2050 (The European Green Deal, European Commission, 2019). As one part of novel FCH technologies, Solid Oxide Cells (SOCs) can be used as fuel cells and electrolyzers, enabling a fuel-flexible and adaptable range of applications. However, the Technology Readiness Level (TRL) of SOCs is currently assessed at 5–7 (H2-international, October 2022), which is lower compared to most of the technologies mentioned above. In order to achieve their market breakthrough, SOCs require scalable and cost-efficient manufacturing trails. This involves an adequate End-of-Life (EoL) material treatment, minimizing environmental impact, and avoiding landfill disposals. EoL strategies for FCH applications (including the SOC) are currently in the early stages and have not been adequately addressed. Until now, existing novel technologies and their materials are reviewed based on hazardousness, scarcity and cost. Initial considerations directly for SOC material recovery are given in two very recent publications. In these two studies, the focus was on the ceramic cell part of an SOC, aiming for the recovery of the most valuable cell fractions in a (semi-) closed loop scenario. Challenges in cell recycling arise from the diversity of structures and materials of established stack and cell designs. For industrial applications, planar stack geometry is likely to prevail, further subdivided based on the mechanical support used (fuel electrode-supported cells, FESC; electrolyte-supported cells, ESCs; metal-supported cells, MSCs). As a part of the German government-funded technology platform “H2Giga”, we are working on the re-integration of EoL FESC-type SOCs into the cell manufacturing process. The concept for FESC-recycling (Figure 1.) is based on the separation of the air-side perovskite materials (air-side electrode and contact layer) from the remaining predominant cell fraction (mechanical support, fuel electrode, electrolyte, and diffusion barrier layer). [1] Separation can be achieved by exploiting the chemical resistance of NiO and YSZ to suitable leachants such as hydrochloric acid or nitric acid. In comparison, the structure of the conventional perovskites used is more vulnerable to acid corrosion. The remaining solid fraction then undergoes a re-dispersion step and is incorporated into newly manufactured substrate. The recycled substrate is characterized in terms of electrical conductivity, mechanical stability, and microstructure. Critical components (Co, La) in the separated perovskite liquid fraction are to be recovered from the solution by precipitation. The presentation will guide the audience through the concept of multi-step recovery of the predominant cell fraction Ni(O)/YSZ, and will provide insides of the experimental results, ranging from the hydrometallurgical separation
{"title":"Recycling and Reuse Strategies for Ceramic Components of Solid Oxide Cells","authors":"Stephan Sarner, Norbert H. Menzler, Andrea Hilgers, Olivier Guillon","doi":"10.1149/ma2023-0154210mtgabs","DOIUrl":"https://doi.org/10.1149/ma2023-0154210mtgabs","url":null,"abstract":"Fuel Cell and Hydrogen (FCH) applications will become crucial to enable the transition towards decarbonatization and meet the EU's zero net greenhouse gas emission targets to be achieved by 2050 (The European Green Deal, European Commission, 2019). As one part of novel FCH technologies, Solid Oxide Cells (SOCs) can be used as fuel cells and electrolyzers, enabling a fuel-flexible and adaptable range of applications. However, the Technology Readiness Level (TRL) of SOCs is currently assessed at 5–7 (H2-international, October 2022), which is lower compared to most of the technologies mentioned above. In order to achieve their market breakthrough, SOCs require scalable and cost-efficient manufacturing trails. This involves an adequate End-of-Life (EoL) material treatment, minimizing environmental impact, and avoiding landfill disposals. EoL strategies for FCH applications (including the SOC) are currently in the early stages and have not been adequately addressed. Until now, existing novel technologies and their materials are reviewed based on hazardousness, scarcity and cost. Initial considerations directly for SOC material recovery are given in two very recent publications. In these two studies, the focus was on the ceramic cell part of an SOC, aiming for the recovery of the most valuable cell fractions in a (semi-) closed loop scenario. Challenges in cell recycling arise from the diversity of structures and materials of established stack and cell designs. For industrial applications, planar stack geometry is likely to prevail, further subdivided based on the mechanical support used (fuel electrode-supported cells, FESC; electrolyte-supported cells, ESCs; metal-supported cells, MSCs). As a part of the German government-funded technology platform “H2Giga”, we are working on the re-integration of EoL FESC-type SOCs into the cell manufacturing process. The concept for FESC-recycling (Figure 1.) is based on the separation of the air-side perovskite materials (air-side electrode and contact layer) from the remaining predominant cell fraction (mechanical support, fuel electrode, electrolyte, and diffusion barrier layer). [1] Separation can be achieved by exploiting the chemical resistance of NiO and YSZ to suitable leachants such as hydrochloric acid or nitric acid. In comparison, the structure of the conventional perovskites used is more vulnerable to acid corrosion. The remaining solid fraction then undergoes a re-dispersion step and is incorporated into newly manufactured substrate. The recycled substrate is characterized in terms of electrical conductivity, mechanical stability, and microstructure. Critical components (Co, La) in the separated perovskite liquid fraction are to be recovered from the solution by precipitation. The presentation will guide the audience through the concept of multi-step recovery of the predominant cell fraction Ni(O)/YSZ, and will provide insides of the experimental results, ranging from the hydrometallurgical separation","PeriodicalId":11461,"journal":{"name":"ECS Meeting Abstracts","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135088808","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 : 2023-08-28DOI: 10.1149/ma2023-01492564mtgabs
Iwona A. Rutkowska, Claudia Janiszewska, Keti Vezzu, Enrico Negro, Vito Di Noto, Pawel J. Kulesza
Concentrated solutions of Keggin-type silicotungstic acid, as well as the system’s single crystals (H 4 SiW 12 O 40 *31H 2 O) and their colloidal suspensions have been tested using the microelectrode methodology to determine mass-transport, electron self-exchange and apparent (effective) diffusion-type coefficients for charge propagation and homogeneous (electron self-exchange) rates of electron transfers. Silicotungstic acid facilitates proton conductivity, and undergoes fast, reversible, multi-electron electron transfers leading to the formation of highly conducting, mixed-valence (tungsten(VI,V) heteropoly blue) compounds. To develop useful electroanalytical diagnostic criteria, electroanalytical approaches utilizing microdisk electrodes have been adapted to characterize redox transitions of the system and to determine kinetic parameters. Combination of micoroelectrode-based experiments performed in two distinct diffusional regimes: radial (long-term experiment; e.g., slow scan rate voltammetry or long-pulse chronoamperometry) and linear (short-term experiment; e.g., fast scan rate voltammetry or short-pulse chronocoulometry) permits absolute determination of such parameters as effective concentration of redox centers ( C 0 ) and apparent transport (diffusion) coefficient ( D app ). The knowledge of these parameters, in particular of [ D app 1/2 C 0 ] seems to be of importance to the evaluation of utility of redox electrolytes for charge storage. While current densities which reflect dynamics of electrochemical processes have an influence on the systems’ current densities, the viscosity of the electrolyte and the mass transport dynamics are also affected by the nature of the redox-active material and its concentration. Trying to develop useful electroanalytical diagnostic approaches, we have successfully utilized microelectrode-based probes, as well as the historical concepts of charge propagation in semi-solid or semi-liquid systems developed for mixed-valence polynuclear materials in order to characterize concentrated redox electrolytes. Among important parameters are concentration of redox centers ( C 0 ) and apparent transport (diffusion) coefficient ( D app ). The knowledge of these parameters and, in particular of [ D app 1/2 C 0 ], are crucial when it comes to evaluation of the diffusional-type charge propagation dynamics in the concentrated electrolyte which may reflect both physical mass transport and electron self-exchange (electron-hopping) contributions. Both potential-step (chronocoulometry, chronoamperometry) and cyclic voltammetric experiments utilizing microdisk electrodes have been adapted to characterization (identification of redox transitions and determination of kinetic parameters) of model inorganic redox electrolytes, namely highly-concentrated solutions or colloidal suspensions of Keggin-type polyoxometallate, silicotungstic acid.
用微电极方法测试了keggin型硅钨酸的浓溶液，以及该体系的单晶(h4siw12o40 * 31h2o)及其胶体悬浮液，以确定电荷传播的质量输运、电子自交换和表观(有效)扩散型系数以及电子转移的均匀(电子自交换)速率。硅钨酸有利于质子导电性，并经历快速，可逆，多电子电子转移，导致形成高导电性，混合价(钨(VI,V)杂多矿蓝)化合物。为了开发有用的电分析诊断标准，利用微盘电极的电分析方法已被用于表征系统的氧化还原转变并确定动力学参数。结合在两种不同扩散机制下进行的基于微电极的实验:径向(长期)实验;例如，慢扫描速率伏安法或长脉冲计时安培法)和线性(短期实验;例如，快速扫描速率伏安法或短脉冲计时库容法)可以绝对确定氧化还原中心的有效浓度(c0)和表观传输(扩散)系数(dapp)等参数。这些参数的知识，特别是[D app 1/2 c0]似乎对评价氧化还原电解质用于电荷存储的效用很重要。虽然反映电化学过程动力学的电流密度会影响系统的电流密度，但电解质的粘度和质量传递动力学也受到氧化还原活性物质的性质及其浓度的影响。为了开发有用的电分析诊断方法，我们成功地利用了基于微电极的探针，以及为混合价多核材料开发的半固体或半液体系统中电荷传播的历史概念，以表征浓氧化还原电解质。其中重要的参数是氧化还原中心浓度(c0)和表观传输(扩散)系数(dapp)。当涉及到浓电解质中扩散型电荷传播动力学的评估时，这些参数的知识，特别是[D app 1/2 C 0]，是至关重要的，这可能反映了物理质量传递和电子自交换(电子跳变)的贡献。利用微盘电极的电位步法(计时库容法、计时安培法)和循环伏安法实验都适用于模型无机氧化还原电解质的表征(氧化还原转变的识别和动力学参数的确定)，即keggin型多金属氧酸硅钨酸的高浓度溶液或胶体悬浮液。
{"title":"(Invited) Microelectrode-Based Diagnosis of Charge Propagation and Redox Transitions in Concentrated Polyoxometallate Electrolyte of Potential Utility for Redox Flow Battery","authors":"Iwona A. Rutkowska, Claudia Janiszewska, Keti Vezzu, Enrico Negro, Vito Di Noto, Pawel J. Kulesza","doi":"10.1149/ma2023-01492564mtgabs","DOIUrl":"https://doi.org/10.1149/ma2023-01492564mtgabs","url":null,"abstract":"Concentrated solutions of Keggin-type silicotungstic acid, as well as the system’s single crystals (H 4 SiW 12 O 40 *31H 2 O) and their colloidal suspensions have been tested using the microelectrode methodology to determine mass-transport, electron self-exchange and apparent (effective) diffusion-type coefficients for charge propagation and homogeneous (electron self-exchange) rates of electron transfers. Silicotungstic acid facilitates proton conductivity, and undergoes fast, reversible, multi-electron electron transfers leading to the formation of highly conducting, mixed-valence (tungsten(VI,V) heteropoly blue) compounds. To develop useful electroanalytical diagnostic criteria, electroanalytical approaches utilizing microdisk electrodes have been adapted to characterize redox transitions of the system and to determine kinetic parameters. Combination of micoroelectrode-based experiments performed in two distinct diffusional regimes: radial (long-term experiment; e.g., slow scan rate voltammetry or long-pulse chronoamperometry) and linear (short-term experiment; e.g., fast scan rate voltammetry or short-pulse chronocoulometry) permits absolute determination of such parameters as effective concentration of redox centers ( C 0 ) and apparent transport (diffusion) coefficient ( D app ). The knowledge of these parameters, in particular of [ D app 1/2 C 0 ] seems to be of importance to the evaluation of utility of redox electrolytes for charge storage. While current densities which reflect dynamics of electrochemical processes have an influence on the systems’ current densities, the viscosity of the electrolyte and the mass transport dynamics are also affected by the nature of the redox-active material and its concentration. Trying to develop useful electroanalytical diagnostic approaches, we have successfully utilized microelectrode-based probes, as well as the historical concepts of charge propagation in semi-solid or semi-liquid systems developed for mixed-valence polynuclear materials in order to characterize concentrated redox electrolytes. Among important parameters are concentration of redox centers ( C 0 ) and apparent transport (diffusion) coefficient ( D app ). The knowledge of these parameters and, in particular of [ D app 1/2 C 0 ], are crucial when it comes to evaluation of the diffusional-type charge propagation dynamics in the concentrated electrolyte which may reflect both physical mass transport and electron self-exchange (electron-hopping) contributions. Both potential-step (chronocoulometry, chronoamperometry) and cyclic voltammetric experiments utilizing microdisk electrodes have been adapted to characterization (identification of redox transitions and determination of kinetic parameters) of model inorganic redox electrolytes, namely highly-concentrated solutions or colloidal suspensions of Keggin-type polyoxometallate, silicotungstic acid.","PeriodicalId":11461,"journal":{"name":"ECS Meeting Abstracts","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135088810","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 : 2023-08-28DOI: 10.1149/ma2023-015498mtgabs
Leonardo Duranti, Andrea Felli, Marcello Marelli, Melodj Dosa, Elisabetta Di Bartolomeo, Marco Piumetti, Marta Boaro
Solid oxide cells (SOCs) are nowadays one of the most promising energy conversion technologies, to accelerate and promote the ongoing energy transition 1,2 , based on the use of renewable resources. These devices in fact allow the development of valuable low carbon footprint power-to-X (X= power, fuels) chains of energy conversion and storage 3 . In this respect is crucial the design of innovative, cost-effective materials and processes for more and more versatile and reversible devices. In the last decade, simple perovskite (ABO 3 ) and double perovskite (A 2 BBʹO 6 ) oxide have been proved to be a valuable alternative to cermet SOC electrodes, thanks to their relative ease of functionalization via doping and exsolution and their mixed ionic-electron conduction 4-6 . Exsolution process is strongly dependent on the type of metal and perovskite and on methodology adopted to induce the reduction 7 . Cathodic electrochemical polarization has been demonstrated to be a valuable approach to boost the exsolution especially from titanate based structures, obtaining higher dispersions than that derived from thermal reduction 8 . In this work, we explored for the first time the behaviour of the double perovskite Sr 2 FeMo 0.6 Ni 0.4 O 6-δ (SFMN) under cathodic polarization and we investigated the impact of the structural evolution on the electrochemical performances of a multi-functional electrode for H 2 -SOFC and CO 2 -SOEC applications. SFMN was prepared by sol gel method and used to prepare supported SFMN/ La 0.8 Sr 0.2 Ga 0.8 Mg 0.2 O 3-δ (LSGM)/La 0.6 Sr 0.4 Fe 0.8 Co 0.2 O 3-δ :Ce 0.9 Gd 0.1 O 2-δ (LSFCo:GDC) cells that were tested either before and after thermal or electrochemical reduction at 850°C. As already reported the thermal reduction of SFMN leads to the exsolution of metal nanoparticles (of Ni or Ni-Fe alloys) and the in situ formation of Ruddlesden-Popper phase 9 (RP). HRTEM, SEM and XRD characterizations of tested cells allowed to observe an acceleration of the structural transformation of perovskite under cathodic polarization in comparison to what observed under thermal reduction. This allows to gain insights on the role of entire transformation on the electrochemical behaviours of cells. Electrochemical properties of SFNM were investigated by EIS analysis. Distribution of relaxation times (DRT) analyses was also used to obtain further insights on the impedance of the different cell mechanisms according to their characteristic frequency. The exsolved metal nanoparticles contributed to improve the conductivity and activity of the electrode, however, also the formation of RP phase seems have a significant role, especially in the electroreduction of CO 2 . Further studies are in progress to better understand the mechanisms of interaction between the phases formed during the exsolution process and their role on SOC electrodes activity. References 1 Hauch et al., Science 370, eaba6118 (2020). 2 M.B. Mogensen et al. Clean Energy, 3 (2019) 17
固体氧化物电池(SOCs)是目前最有前途的能量转换技术之一，可以加速和促进基于可再生资源的能源转型1,2。事实上，这些设备允许开发有价值的低碳足迹的能量转换和存储链(X=电力，燃料)。在这方面是至关重要的创新，具有成本效益的材料和工艺的设计越来越多的通用和可逆的设备。在过去的十年中，简单钙钛矿(ABO 3)和双钙钛矿(a2 BB O 6)氧化物已被证明是金属陶瓷SOC电极的有价值的替代品，这得益于它们相对容易通过掺杂和溶出实现功能化以及它们的混合离子电子传导4-6。析出过程在很大程度上取决于金属和钙钛矿的类型以及诱导还原所采用的方法7。阴极电化学极化已被证明是一种有价值的方法，可以促进钛酸盐基结构的析出，获得比热还原得到的更高的分散度8。在这项工作中，我们首次探索了双钙钛矿Sr 2 FeMo 0.6 Ni 0.4 O 6-δ (SFMN)在阴极极化下的行为，并研究了结构演变对用于h2 -SOFC和CO 2 -SOEC的多功能电极电化学性能的影响。采用溶胶-凝胶法制备SFMN，并制备了负载式SFMN/ La 0.8 Sr 0.2 Ga 0.8 Mg 0.2 O 3-δ (LSGM)/La 0.6 Sr 0.4 Fe 0.8 Co 0.2 O 3-δ:Ce 0.9 Gd 0.1 O 2-δ (LSFCo:GDC)电池，在850℃下进行了热还原和电化学还原前后的测试。如前所述，SFMN的热还原导致金属纳米颗粒(Ni或Ni- fe合金)的析出和Ruddlesden-Popper相9 (RP)的原位形成。对测试电池的HRTEM, SEM和XRD表征表明，与热还原相比，钙钛矿在阴极极化下的结构转变加速。这使得我们能够深入了解整个转化过程在细胞电化学行为中的作用。采用EIS分析研究了SFNM的电化学性能。弛豫时间分布(DRT)分析也用于进一步了解不同细胞机制根据其特征频率的阻抗。溶解的金属纳米颗粒有助于提高电极的电导率和活性，然而，RP相的形成似乎也有重要的作用，特别是在CO 2的电还原中。为了更好地了解析出过程中形成的相之间的相互作用机制及其对SOC电极活性的影响，进一步的研究正在进行中。1 Hauch et al.， Science 370, eaba6118(2020)。2 M.B. Mogensen等。清洁能源，3 (2019):175-201 3 F。Salomone等化学。Eng。[3]中国科学:自然科学版(2019)，1233 - 1233。ervine, j.t.s。sofc的钙钛矿氧化物阳极。固体氧化物燃料电池用钙钛矿氧化物石原，T.， Ed;斯普林格美国:波士顿，马萨诸塞州，2009;页167 - 182。5. 尹伟，等。能源环境。科学通报，12 (2019):442-462Q. Islam等人。[j] .能源科学与技术，2016，(2):1 - 6。7. O. Kwon等。期刊。能源学报，(2020)，032001Jh，明，Jh。et al。《自然》，(2016)528-531。z;中国生物医学工程学报，2016,33 (2):669 - 669
{"title":"Study on Exsolution Process of Sr<sub>2</sub>FeMo<sub>0.6</sub>Ni<sub>0.4</sub>O<sub>6 </sub>via in Situ Cathodic Polarization","authors":"Leonardo Duranti, Andrea Felli, Marcello Marelli, Melodj Dosa, Elisabetta Di Bartolomeo, Marco Piumetti, Marta Boaro","doi":"10.1149/ma2023-015498mtgabs","DOIUrl":"https://doi.org/10.1149/ma2023-015498mtgabs","url":null,"abstract":"Solid oxide cells (SOCs) are nowadays one of the most promising energy conversion technologies, to accelerate and promote the ongoing energy transition 1,2 , based on the use of renewable resources. These devices in fact allow the development of valuable low carbon footprint power-to-X (X= power, fuels) chains of energy conversion and storage 3 . In this respect is crucial the design of innovative, cost-effective materials and processes for more and more versatile and reversible devices. In the last decade, simple perovskite (ABO 3 ) and double perovskite (A 2 BBʹO 6 ) oxide have been proved to be a valuable alternative to cermet SOC electrodes, thanks to their relative ease of functionalization via doping and exsolution and their mixed ionic-electron conduction 4-6 . Exsolution process is strongly dependent on the type of metal and perovskite and on methodology adopted to induce the reduction 7 . Cathodic electrochemical polarization has been demonstrated to be a valuable approach to boost the exsolution especially from titanate based structures, obtaining higher dispersions than that derived from thermal reduction 8 . In this work, we explored for the first time the behaviour of the double perovskite Sr 2 FeMo 0.6 Ni 0.4 O 6-δ (SFMN) under cathodic polarization and we investigated the impact of the structural evolution on the electrochemical performances of a multi-functional electrode for H 2 -SOFC and CO 2 -SOEC applications. SFMN was prepared by sol gel method and used to prepare supported SFMN/ La 0.8 Sr 0.2 Ga 0.8 Mg 0.2 O 3-δ (LSGM)/La 0.6 Sr 0.4 Fe 0.8 Co 0.2 O 3-δ :Ce 0.9 Gd 0.1 O 2-δ (LSFCo:GDC) cells that were tested either before and after thermal or electrochemical reduction at 850°C. As already reported the thermal reduction of SFMN leads to the exsolution of metal nanoparticles (of Ni or Ni-Fe alloys) and the in situ formation of Ruddlesden-Popper phase 9 (RP). HRTEM, SEM and XRD characterizations of tested cells allowed to observe an acceleration of the structural transformation of perovskite under cathodic polarization in comparison to what observed under thermal reduction. This allows to gain insights on the role of entire transformation on the electrochemical behaviours of cells. Electrochemical properties of SFNM were investigated by EIS analysis. Distribution of relaxation times (DRT) analyses was also used to obtain further insights on the impedance of the different cell mechanisms according to their characteristic frequency. The exsolved metal nanoparticles contributed to improve the conductivity and activity of the electrode, however, also the formation of RP phase seems have a significant role, especially in the electroreduction of CO 2 . Further studies are in progress to better understand the mechanisms of interaction between the phases formed during the exsolution process and their role on SOC electrodes activity. References 1 Hauch et al., Science 370, eaba6118 (2020). 2 M.B. Mogensen et al. Clean Energy, 3 (2019) 17","PeriodicalId":11461,"journal":{"name":"ECS Meeting Abstracts","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135088813","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 : 2023-08-28DOI: 10.1149/ma2023-01402853mtgabs
Krishnan Rajeshwar
This perspective talk focuses on the history and status of new materials with targeted application in solar energy conversion. Specifically, photoelectrochemical energy conversion/solar water splitting and wide bandgap oxide semiconductors and alloys for solar windows and displays are the two targeted application areas. The Cu-M-V-O family of oxide semiconductors will be discussed in this poster. Both synthetic aspects and chemical composition-property-performance correlations will be presented. Acknowledgements. This work was primarily supported by the National Science Foundation UTA/NU Partnership for Research and Education in Materials (NSF DMR-2122128).
{"title":"Ternary Oxide Semiconductors and Alloys: Hope and Reality","authors":"Krishnan Rajeshwar","doi":"10.1149/ma2023-01402853mtgabs","DOIUrl":"https://doi.org/10.1149/ma2023-01402853mtgabs","url":null,"abstract":"This perspective talk focuses on the history and status of new materials with targeted application in solar energy conversion. Specifically, photoelectrochemical energy conversion/solar water splitting and wide bandgap oxide semiconductors and alloys for solar windows and displays are the two targeted application areas. The Cu-M-V-O family of oxide semiconductors will be discussed in this poster. Both synthetic aspects and chemical composition-property-performance correlations will be presented. Acknowledgements. This work was primarily supported by the National Science Foundation UTA/NU Partnership for Research and Education in Materials (NSF DMR-2122128).","PeriodicalId":11461,"journal":{"name":"ECS Meeting Abstracts","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135088820","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 : 2023-08-28DOI: 10.1149/ma2023-01552666mtgabs
Bala Krishnan Ganesan, Megala Moorthy, Yeong-A Kim, Hariharan Dhanasekaran, Jeong-Hyeon Song, Yun-Sung Lee
Sodium ion batteries are considered as a cost-effective and promising alternative to lithium-ion batteries for next generation large-scale energy storage applications. However, the sluggish intercalation kinetics and poor stability plagues the efficient applications. Recently, sodium rich cathode materials are emerging as a promising system to retain high specific energy with improved durability. Benefitting from the high Na ion mobility by P2-type structure and reduced John-Teller active Mn site, improved stability has been achieved for this Na-rich cathode. In this work, we developed a high performing Na rich cathode with Sodium Manganese Oxyfluoride ( Na 1.2 Mn 0.8 O 1.5 F 0.5 ) as a battery positive electrode. The corresponding structural and electrochemical performances are analysed in solid-state battery. The highly favourable cathode architecture demonstrated a high specific capacity of 178 mAh/g at 10 mA/g in half-cell configuration. To further harness its performance, the cathode material was coupled with solid-electrolyte and interface modified anode. Solid-state battery demonstrated an enhanced capability towards ion storage and better stability.
钠离子电池被认为是下一代大规模储能应用中锂离子电池的一种具有成本效益和前景的替代品。然而，插层动力学缓慢，稳定性差，影响了其高效应用。近年来，富钠阴极材料作为一种具有高比能和高耐久性的极具发展前景的材料而崭露头角。利用p2型结构的高Na离子迁移率和减少的John-Teller活性Mn位，该富Na阴极的稳定性得到了提高。在这项工作中，我们开发了一种高性能富钠阴极，以氟化氧化锰钠(Na 1.2 Mn 0.8 O 1.5 F 0.5)作为电池正极。在固态电池中分析了相应的结构和电化学性能。极好的阴极结构在10 mA/g时具有178 mAh/g的高比容量。为了进一步发挥其性能，阴极材料与固体电解质和界面改性阳极耦合。固态电池表现出增强的离子存储能力和更好的稳定性。
{"title":"A Study on Na<sub>1.2</sub>Mn<sub>0.8</sub>O<sub>1.5</sub>F<sub>0.5</sub> Na-Rich Cathode Material for High Capacity and Superior Stability Sodium Solid-State Battery","authors":"Bala Krishnan Ganesan, Megala Moorthy, Yeong-A Kim, Hariharan Dhanasekaran, Jeong-Hyeon Song, Yun-Sung Lee","doi":"10.1149/ma2023-01552666mtgabs","DOIUrl":"https://doi.org/10.1149/ma2023-01552666mtgabs","url":null,"abstract":"Sodium ion batteries are considered as a cost-effective and promising alternative to lithium-ion batteries for next generation large-scale energy storage applications. However, the sluggish intercalation kinetics and poor stability plagues the efficient applications. Recently, sodium rich cathode materials are emerging as a promising system to retain high specific energy with improved durability. Benefitting from the high Na ion mobility by P2-type structure and reduced John-Teller active Mn site, improved stability has been achieved for this Na-rich cathode. In this work, we developed a high performing Na rich cathode with Sodium Manganese Oxyfluoride ( Na 1.2 Mn 0.8 O 1.5 F 0.5 ) as a battery positive electrode. The corresponding structural and electrochemical performances are analysed in solid-state battery. The highly favourable cathode architecture demonstrated a high specific capacity of 178 mAh/g at 10 mA/g in half-cell configuration. To further harness its performance, the cathode material was coupled with solid-electrolyte and interface modified anode. Solid-state battery demonstrated an enhanced capability towards ion storage and better stability.","PeriodicalId":11461,"journal":{"name":"ECS Meeting Abstracts","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135088835","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：