Pub Date : 2023-05-11DOI: 10.1088/2515-7655/acd47d
C. Salazar Mejía, T. Niehoff, M. Straßheim, E. Bykov, Y. Skourski, J. Wosnitza, T. Gottschall
Magnetic refrigeration is a highly active field of research. The recent studies in materials and methods for hydrogen liquefaction and innovative techniques based on multicaloric materials have significantly expanded the scope of the field. For this reason, the proper characterization of materials is now more crucial than ever. This makes it necessary to determine the magnetocaloric and other physical properties under various stimuli such as magnetic fields and mechanical loads. In this work, we present an overview of the characterization techniques established at the Dresden High Magnetic Field Laboratory in recent years, which specializes in using pulsed magnetic fields. The short duration of magnetic-field pulses, lasting only some ten milliseconds, simplifies the process of ensuring adiabatic conditions for the determination of temperature changes, ΔTad . The possibility to measure in the temperature range from 10 to 400 K allows us to study magnetocaloric materials for both room-temperature applications and gas liquefaction. With magnetic-field strengths of up to 50 T, almost every first-order material can be transformed completely. The high field-change rates allow us to observe dynamic effects of phase transitions driven by nucleation and growth as well. We discuss the experimental challenges and advantages of the investigation method using pulsed magnetic fields. We summarize examples for some of the most important material classes including Gd, Laves phases, La–Fe–Si, Mn–Fe–P–Si, Heusler alloys and Fe–Rh. Further, we present the recent developments in simultaneous measurements of temperature change, strain, and magnetization, and introduce a technique to characterize multicaloric materials under applied magnetic field and uniaxial load. We conclude by demonstrating how the use of pulsed fields opens the door to new magnetic-refrigeration principles based on multicalorics and the ‘exploiting-hysteresis’ approach.
{"title":"On the high-field characterization of magnetocaloric materials using pulsed magnetic fields","authors":"C. Salazar Mejía, T. Niehoff, M. Straßheim, E. Bykov, Y. Skourski, J. Wosnitza, T. Gottschall","doi":"10.1088/2515-7655/acd47d","DOIUrl":"https://doi.org/10.1088/2515-7655/acd47d","url":null,"abstract":"Magnetic refrigeration is a highly active field of research. The recent studies in materials and methods for hydrogen liquefaction and innovative techniques based on multicaloric materials have significantly expanded the scope of the field. For this reason, the proper characterization of materials is now more crucial than ever. This makes it necessary to determine the magnetocaloric and other physical properties under various stimuli such as magnetic fields and mechanical loads. In this work, we present an overview of the characterization techniques established at the Dresden High Magnetic Field Laboratory in recent years, which specializes in using pulsed magnetic fields. The short duration of magnetic-field pulses, lasting only some ten milliseconds, simplifies the process of ensuring adiabatic conditions for the determination of temperature changes, ΔTad . The possibility to measure in the temperature range from 10 to 400 K allows us to study magnetocaloric materials for both room-temperature applications and gas liquefaction. With magnetic-field strengths of up to 50 T, almost every first-order material can be transformed completely. The high field-change rates allow us to observe dynamic effects of phase transitions driven by nucleation and growth as well. We discuss the experimental challenges and advantages of the investigation method using pulsed magnetic fields. We summarize examples for some of the most important material classes including Gd, Laves phases, La–Fe–Si, Mn–Fe–P–Si, Heusler alloys and Fe–Rh. Further, we present the recent developments in simultaneous measurements of temperature change, strain, and magnetization, and introduce a technique to characterize multicaloric materials under applied magnetic field and uniaxial load. We conclude by demonstrating how the use of pulsed fields opens the door to new magnetic-refrigeration principles based on multicalorics and the ‘exploiting-hysteresis’ approach.","PeriodicalId":48500,"journal":{"name":"Journal of Physics-Energy","volume":" ","pages":""},"PeriodicalIF":6.9,"publicationDate":"2023-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41435359","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-10DOI: 10.1088/2515-7655/acd41a
S. L. Dreyer, Ruizhuo Zhang, Junbo Wang, A. Kondrakov, Qingsong Wang, T. Brezesinski, J. Janek
Sodium-ion batteries (SIBs) see intensive research and commercialization efforts, aiming to establish them as an alternative to lithium-ion batteries. Among the reported cathode material families for SIBs, Na-deficient P2-type layered oxides are promising candidates, benefiting from fast sodium diffusion and therefore high charge/discharge rates. However, upon sodium extraction at high potentials, a transition from the P2 to O2 phase occurs, with the corresponding change in cell volume resulting in particle fracture and capacity degradation. A possible solution to this is to increase configurational entropy by introducing more elements into the transition-metal layer (so-called high-entropy concept), leading to some kind of structural stabilization. In this work, the acoustic emission (AE) of a series of P2-type layered oxide cathodes with increasing configurational entropy [Na0.67(Mn0.55Ni0.21Co0.24)O2, Na0.67(Mn0.45Ni0.18Co0.24Ti0.1Mg0.03)O2 and Na0.67(Mn0.45Ni0.18Co0.18Ti0.1Mg0.03Al0.04Fe0.02)O2] is recorded during SIB operation and correlated to the materials properties, namely change in c lattice parameter and cracking behavior. A structure-property relationship between entropy, manifested in the extent of phase transition, and detected AE is derived, supported by the classification of signals by peak frequency. This classification in combination with microscopy imaging allows to distinguish between inter- and intragranular fracture. Relatively more intergranular and less intragranular crack formation is observed with increasing configurational entropy.
{"title":"The effect of configurational entropy on acoustic emission of P2-type layered oxide cathodes for sodium-ion batteries","authors":"S. L. Dreyer, Ruizhuo Zhang, Junbo Wang, A. Kondrakov, Qingsong Wang, T. Brezesinski, J. Janek","doi":"10.1088/2515-7655/acd41a","DOIUrl":"https://doi.org/10.1088/2515-7655/acd41a","url":null,"abstract":"Sodium-ion batteries (SIBs) see intensive research and commercialization efforts, aiming to establish them as an alternative to lithium-ion batteries. Among the reported cathode material families for SIBs, Na-deficient P2-type layered oxides are promising candidates, benefiting from fast sodium diffusion and therefore high charge/discharge rates. However, upon sodium extraction at high potentials, a transition from the P2 to O2 phase occurs, with the corresponding change in cell volume resulting in particle fracture and capacity degradation. A possible solution to this is to increase configurational entropy by introducing more elements into the transition-metal layer (so-called high-entropy concept), leading to some kind of structural stabilization. In this work, the acoustic emission (AE) of a series of P2-type layered oxide cathodes with increasing configurational entropy [Na0.67(Mn0.55Ni0.21Co0.24)O2, Na0.67(Mn0.45Ni0.18Co0.24Ti0.1Mg0.03)O2 and Na0.67(Mn0.45Ni0.18Co0.18Ti0.1Mg0.03Al0.04Fe0.02)O2] is recorded during SIB operation and correlated to the materials properties, namely change in c lattice parameter and cracking behavior. A structure-property relationship between entropy, manifested in the extent of phase transition, and detected AE is derived, supported by the classification of signals by peak frequency. This classification in combination with microscopy imaging allows to distinguish between inter- and intragranular fracture. Relatively more intergranular and less intragranular crack formation is observed with increasing configurational entropy.","PeriodicalId":48500,"journal":{"name":"Journal of Physics-Energy","volume":" ","pages":""},"PeriodicalIF":6.9,"publicationDate":"2023-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42733342","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-28DOI: 10.1088/2515-7655/acd146
D. Neagu, J. Irvine, Jiayue Wang, B. Yildiz, A. Opitz, Juergen Fleig, Yuhao Wang, Jiapeng Liu, Longyun Shen, F. Ciucci, B. A. Rosen, Yongchun Xiao, Kui Xie, Guangming Yang, Zongping Shao, Yubo Zhang, Jakob Michael Reinke, T. A. Schmauss, S. Barnett, R. Maring, V. Kyriakou, Usman Mushtaq, M. N. Tsampas, You-Dong Kim, R. O'Hayre, A. J. Carrillo, T. Ruh, L. Lindenthal, F. Schrenk, C. Rameshan, E. Papaioannou, Kalliopi Kousi, I. Metcalfe, Xiaoxiang Xu, Gang Liu
Over the last decade, exsolution has emerged as a powerful new method for decorating oxide supports with uniformly dispersed nanoparticles for energy and catalytic applications. Due to their exceptional anchorage, resilience to various degradation mechanisms, as well as numerous ways in which they can be produced, transformed and applied, exsolved nanoparticles have set new standards for nanoparticles in terms of activity, durability and functionality. In conjunction with multifunctional supports such as perovskite oxides, exsolution becomes a powerful platform for the design of advanced energy materials. In the following sections, we review the current status of the exsolution approach, seeking to facilitate transfer of ideas between different fields of application. We also explore future directions of research, particularly noting the multi-scale development required to take the concept forward, from fundamentals through operando studies to pilot scale demonstrations.
{"title":"Roadmap on exsolution for energy applications","authors":"D. Neagu, J. Irvine, Jiayue Wang, B. Yildiz, A. Opitz, Juergen Fleig, Yuhao Wang, Jiapeng Liu, Longyun Shen, F. Ciucci, B. A. Rosen, Yongchun Xiao, Kui Xie, Guangming Yang, Zongping Shao, Yubo Zhang, Jakob Michael Reinke, T. A. Schmauss, S. Barnett, R. Maring, V. Kyriakou, Usman Mushtaq, M. N. Tsampas, You-Dong Kim, R. O'Hayre, A. J. Carrillo, T. Ruh, L. Lindenthal, F. Schrenk, C. Rameshan, E. Papaioannou, Kalliopi Kousi, I. Metcalfe, Xiaoxiang Xu, Gang Liu","doi":"10.1088/2515-7655/acd146","DOIUrl":"https://doi.org/10.1088/2515-7655/acd146","url":null,"abstract":"Over the last decade, exsolution has emerged as a powerful new method for decorating oxide supports with uniformly dispersed nanoparticles for energy and catalytic applications. Due to their exceptional anchorage, resilience to various degradation mechanisms, as well as numerous ways in which they can be produced, transformed and applied, exsolved nanoparticles have set new standards for nanoparticles in terms of activity, durability and functionality. In conjunction with multifunctional supports such as perovskite oxides, exsolution becomes a powerful platform for the design of advanced energy materials. In the following sections, we review the current status of the exsolution approach, seeking to facilitate transfer of ideas between different fields of application. We also explore future directions of research, particularly noting the multi-scale development required to take the concept forward, from fundamentals through operando studies to pilot scale demonstrations.","PeriodicalId":48500,"journal":{"name":"Journal of Physics-Energy","volume":" ","pages":""},"PeriodicalIF":6.9,"publicationDate":"2023-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48534275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-25DOI: 10.1088/2515-7655/acd028
M. Gilbert
Nuclear data, describing neutron reaction probabilities (cross sections) and decay behaviour, are critical to the design and operation of fusion experiments and future fusion power plants. Equally vital, are the inventory codes that use the data to predict neutron-induced activation and transmutation of materials, which will define the radiological hazards that must be managed during reactor operation and decommissioning. Transmutation, including gas production, combined with the neutron-induced displacement damage, will also cause the properties of materials to degrade, for example through swelling and embrittlement, eventually limiting the lifetime of components. Thus validated and accurate nuclear data and inventory codes are essential. For data validation there are decay heat measurements performed at FNS in Japan more than 20 years ago. The experiments produced an invaluable database for benchmarking of nuclear data libraries; the latest versions of several international libraries perform well against this data during tests with the FISPACT-II inventory code, although there is still scope for improvement. A recent attempt to provide fusion-relevant validation based on γ-spectroscopy data from neutron-irradiated material samples tests produced predictions for short-lived (several hours or less) radionuclides. The detailed analysis performed for molybdenum demonstrates how these data could eventually provide a new benchmark, and also illustrates the potential benefits of further experiments targeting the longer-lived radionuclides relevant to maintenance and decommissioning timescales. There are also some successful tests of transmutation predictions with FISPACT-II. These direct validations of inventory simulations are critical for lifetime predictions and future experiments should learn lessons from the examples described for tungsten, which demonstrate the importance of an accurate description of the neutron spectrum in experiments. More novel experimental techniques are needed to measure helium production in materials such as Fe and C, but the need to validate the nuclear data evaluations used by simulations should motivate future experimental efforts.
{"title":"Nuclear data for fusion: inventory validation successes and future needs","authors":"M. Gilbert","doi":"10.1088/2515-7655/acd028","DOIUrl":"https://doi.org/10.1088/2515-7655/acd028","url":null,"abstract":"Nuclear data, describing neutron reaction probabilities (cross sections) and decay behaviour, are critical to the design and operation of fusion experiments and future fusion power plants. Equally vital, are the inventory codes that use the data to predict neutron-induced activation and transmutation of materials, which will define the radiological hazards that must be managed during reactor operation and decommissioning. Transmutation, including gas production, combined with the neutron-induced displacement damage, will also cause the properties of materials to degrade, for example through swelling and embrittlement, eventually limiting the lifetime of components. Thus validated and accurate nuclear data and inventory codes are essential. For data validation there are decay heat measurements performed at FNS in Japan more than 20 years ago. The experiments produced an invaluable database for benchmarking of nuclear data libraries; the latest versions of several international libraries perform well against this data during tests with the FISPACT-II inventory code, although there is still scope for improvement. A recent attempt to provide fusion-relevant validation based on γ-spectroscopy data from neutron-irradiated material samples tests produced predictions for short-lived (several hours or less) radionuclides. The detailed analysis performed for molybdenum demonstrates how these data could eventually provide a new benchmark, and also illustrates the potential benefits of further experiments targeting the longer-lived radionuclides relevant to maintenance and decommissioning timescales. There are also some successful tests of transmutation predictions with FISPACT-II. These direct validations of inventory simulations are critical for lifetime predictions and future experiments should learn lessons from the examples described for tungsten, which demonstrate the importance of an accurate description of the neutron spectrum in experiments. More novel experimental techniques are needed to measure helium production in materials such as Fe and C, but the need to validate the nuclear data evaluations used by simulations should motivate future experimental efforts.","PeriodicalId":48500,"journal":{"name":"Journal of Physics-Energy","volume":" ","pages":""},"PeriodicalIF":6.9,"publicationDate":"2023-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42414098","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-21DOI: 10.1088/2515-7655/accf34
Aleksandra Bojar, D. Micha, M. Giteau, M. A. Ruiz‐Preciado, U. Paetzold, M. Simor, Veronique Gevaerts, R. Carron, Karim Medjoubi, S. Collin, N. Naghavi, J. Guillemoles, P. Schulz
In this work we employ the transfer matrix method for the analysis of optical materials properties to simulate and optimize monolithic tandem solar cell devices based on CuIn1−x Ga x Se2, CI(G)S, and perovskite (PVK) absorbers. By finding models that fit well the experimental data of the CI(G)S solar cell, the semitransparent perovskite solar cell (PSC) and the PVK/CI(G)S monolithic tandem solar cell, we were able to perform a detailed optical loss analysis that allowed us to determine sources of parasitic absorption. We found better substitute materials for the transport layers to increase the power conversion efficiency and, in case of semitransparent PSCs, sub-bandgap transmittance. Our results set guidelines for the monolithic PVK/CI(G)S tandem solar cells development, predicting an achievable efficiency of 30%.
在这项工作中，我们采用转移矩阵方法分析光学材料的性能，以模拟和优化基于CuIn1−x Ga x Se2、CI（G）S和钙钛矿（PVK）吸收剂的单片串联太阳能电池器件。通过找到与CI（G）S太阳能电池、半透明钙钛矿太阳能电池（PSC）和PVK/Cl（G）S单片串联太阳能电池的实验数据非常吻合的模型，我们能够进行详细的光学损耗分析，从而确定寄生吸收的来源。我们发现了更好的传输层替代材料，以提高功率转换效率，在半透明PSC的情况下，还可以提高亚带隙透射率。我们的研究结果为单片PVK/CI（G）S串联太阳能电池的开发提供了指导，预测可实现30%的效率。
{"title":"Optical simulations and optimization of perovskite/CI(G)S tandem solar cells using the transfer matrix method","authors":"Aleksandra Bojar, D. Micha, M. Giteau, M. A. Ruiz‐Preciado, U. Paetzold, M. Simor, Veronique Gevaerts, R. Carron, Karim Medjoubi, S. Collin, N. Naghavi, J. Guillemoles, P. Schulz","doi":"10.1088/2515-7655/accf34","DOIUrl":"https://doi.org/10.1088/2515-7655/accf34","url":null,"abstract":"In this work we employ the transfer matrix method for the analysis of optical materials properties to simulate and optimize monolithic tandem solar cell devices based on CuIn1−x Ga x Se2, CI(G)S, and perovskite (PVK) absorbers. By finding models that fit well the experimental data of the CI(G)S solar cell, the semitransparent perovskite solar cell (PSC) and the PVK/CI(G)S monolithic tandem solar cell, we were able to perform a detailed optical loss analysis that allowed us to determine sources of parasitic absorption. We found better substitute materials for the transport layers to increase the power conversion efficiency and, in case of semitransparent PSCs, sub-bandgap transmittance. Our results set guidelines for the monolithic PVK/CI(G)S tandem solar cells development, predicting an achievable efficiency of 30%.","PeriodicalId":48500,"journal":{"name":"Journal of Physics-Energy","volume":" ","pages":""},"PeriodicalIF":6.9,"publicationDate":"2023-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41908128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-19DOI: 10.1088/2515-7655/acce6e
C. Romero-Muñiz, J. Law, L. M. Moreno-Ramírez, Á. Díaz-García, V. Franco
In most cases, substitution studies that aim to optimize magnetic properties are performed at the magnetic atomic site. However, in the case of MnB, magnetic substitutions at the Mn site significantly decrease the once promising magnetocaloric and magnetic properties. This study employs computationally directed search to optimize the magnetocaloric properties of MnB where partial substitutions of boron atoms (Mn50B50− x Si x and Mn50B50− x Ge x where x = 3.125, 6.25, and 12.5) reveal new compounds with a greater magnetocaloric effect than pure MnB at the same Curie temperature. These new compounds were obtained by arc melting the pure elements and further characterized. The computationally driven screening process is based on density functional theory calculations that do not require large databases of known compounds. This work demonstrates that using simple computational screening procedures to search for new magnetocaloric materials with improved properties can be done quickly, cost-effectively, and while maintaining reliability.
{"title":"Using a computationally driven screening to enhance magnetocaloric effect of metal monoborides","authors":"C. Romero-Muñiz, J. Law, L. M. Moreno-Ramírez, Á. Díaz-García, V. Franco","doi":"10.1088/2515-7655/acce6e","DOIUrl":"https://doi.org/10.1088/2515-7655/acce6e","url":null,"abstract":"In most cases, substitution studies that aim to optimize magnetic properties are performed at the magnetic atomic site. However, in the case of MnB, magnetic substitutions at the Mn site significantly decrease the once promising magnetocaloric and magnetic properties. This study employs computationally directed search to optimize the magnetocaloric properties of MnB where partial substitutions of boron atoms (Mn50B50− x Si x and Mn50B50− x Ge x where x = 3.125, 6.25, and 12.5) reveal new compounds with a greater magnetocaloric effect than pure MnB at the same Curie temperature. These new compounds were obtained by arc melting the pure elements and further characterized. The computationally driven screening process is based on density functional theory calculations that do not require large databases of known compounds. This work demonstrates that using simple computational screening procedures to search for new magnetocaloric materials with improved properties can be done quickly, cost-effectively, and while maintaining reliability.","PeriodicalId":48500,"journal":{"name":"Journal of Physics-Energy","volume":" ","pages":""},"PeriodicalIF":6.9,"publicationDate":"2023-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46983186","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-14DOI: 10.1088/2515-7655/accd21
T. Yamazaki, Andre L. Montagnoli, M. L. Young, I. Takeuchi
Caloric cooling enlisting solid-state refrigerants is potentially a promising eco-friendly alternative to conventional cooling based on vapor compression. The most common refrigerant materials for elastocaloric cooling to date are Ni-Ti based superelastic shape memory alloys. Here, we have explored tuning the operation temperature range of Ni50.8Ti49.2 for elastocaloric cooling. In particular, we have studied the effect of thermal treatments (a.k.a. aging) on the transformation temperature, superelasticity, and elastocaloric effects of Ni50.8Ti49.2 shape memory alloy tubes. The isothermal compressive test revealed that the residual strain of thermally-treated Ni-Ti tubes at room temperature approaches zero as aging time is increased. Short-time aging treatment at 400 °C resulted in good superelasticity and elastocaloric cooling performance with a large tunable austenite finish (A f) temperature range of 24.7 °C, as determined from the A f temperature of the samples that were aged 5–120 min. The main reason of the property change is the formation of a different amount of Ni4Ti3 precipitates in the NiTi matrix. Our findings show that it is possible to tailor the A f temperature range for development of cascade elastocaloric cooling systems by thermally treating a starting single composition Ni-Ti alloy.
{"title":"Tuning the temperature range of superelastic Ni-Ti alloys for elastocaloric cooling via thermal processing","authors":"T. Yamazaki, Andre L. Montagnoli, M. L. Young, I. Takeuchi","doi":"10.1088/2515-7655/accd21","DOIUrl":"https://doi.org/10.1088/2515-7655/accd21","url":null,"abstract":"Caloric cooling enlisting solid-state refrigerants is potentially a promising eco-friendly alternative to conventional cooling based on vapor compression. The most common refrigerant materials for elastocaloric cooling to date are Ni-Ti based superelastic shape memory alloys. Here, we have explored tuning the operation temperature range of Ni50.8Ti49.2 for elastocaloric cooling. In particular, we have studied the effect of thermal treatments (a.k.a. aging) on the transformation temperature, superelasticity, and elastocaloric effects of Ni50.8Ti49.2 shape memory alloy tubes. The isothermal compressive test revealed that the residual strain of thermally-treated Ni-Ti tubes at room temperature approaches zero as aging time is increased. Short-time aging treatment at 400 °C resulted in good superelasticity and elastocaloric cooling performance with a large tunable austenite finish (A f) temperature range of 24.7 °C, as determined from the A f temperature of the samples that were aged 5–120 min. The main reason of the property change is the formation of a different amount of Ni4Ti3 precipitates in the NiTi matrix. Our findings show that it is possible to tailor the A f temperature range for development of cascade elastocaloric cooling systems by thermally treating a starting single composition Ni-Ti alloy.","PeriodicalId":48500,"journal":{"name":"Journal of Physics-Energy","volume":" ","pages":""},"PeriodicalIF":6.9,"publicationDate":"2023-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48158610","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-13DOI: 10.1088/2515-7655/acccb1
Xin-yi Lin, Justin Zhu Yeow Seow, Zhichuan J. Xu
Proton exchange membrane water electrolyzer (PEMWE) is a major enabler of green hydrogen production. The development of water electrolyzers is a vital step in driving the progress of a hydrogen-based economy. The system inside the electrolyzer is a zero-gap cell featuring low ohmic resistance and boosted mass transport, leading to higher energy efficiency and minimized capital cost. Besides, utilizing PEM in the electrolyzer for sustainable hydrogen production enables the system to perform with many advantages, including superior energy efficiency, higher hydrogen purity, and high flexibility. Therefore, as PEM electrolyzers continue to evolve, sustainable hydrogen production on a larger scale will be realized in the near future. This review summarizes the status quo of PEM water electrolyzers in the past four years. We will start with a brief introduction of the core of a water electrolyzer, namely the membrane electrode assembly (MEA), which will be followed by an introduction of fabrication methods of MEA, including CCM methods, catalyst-coated electrode methods, and other innovative fabrication methods. Next, we will summarize recent attempts to modify electrodes and membranes in MEAs to promote the performance of PEMWE. Subsequently, catalyst development for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in MEA is discussed, highlighting novel HER/OER catalysts and strategies to reduce the content of noble metals. Lastly, conclusion and perspectives are provided to present a blueprint to inspire the future development of PEMWE.
{"title":"A brief introduction of electrode fabrication for proton exchange membrane water electrolyzers","authors":"Xin-yi Lin, Justin Zhu Yeow Seow, Zhichuan J. Xu","doi":"10.1088/2515-7655/acccb1","DOIUrl":"https://doi.org/10.1088/2515-7655/acccb1","url":null,"abstract":"Proton exchange membrane water electrolyzer (PEMWE) is a major enabler of green hydrogen production. The development of water electrolyzers is a vital step in driving the progress of a hydrogen-based economy. The system inside the electrolyzer is a zero-gap cell featuring low ohmic resistance and boosted mass transport, leading to higher energy efficiency and minimized capital cost. Besides, utilizing PEM in the electrolyzer for sustainable hydrogen production enables the system to perform with many advantages, including superior energy efficiency, higher hydrogen purity, and high flexibility. Therefore, as PEM electrolyzers continue to evolve, sustainable hydrogen production on a larger scale will be realized in the near future. This review summarizes the status quo of PEM water electrolyzers in the past four years. We will start with a brief introduction of the core of a water electrolyzer, namely the membrane electrode assembly (MEA), which will be followed by an introduction of fabrication methods of MEA, including CCM methods, catalyst-coated electrode methods, and other innovative fabrication methods. Next, we will summarize recent attempts to modify electrodes and membranes in MEAs to promote the performance of PEMWE. Subsequently, catalyst development for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in MEA is discussed, highlighting novel HER/OER catalysts and strategies to reduce the content of noble metals. Lastly, conclusion and perspectives are provided to present a blueprint to inspire the future development of PEMWE.","PeriodicalId":48500,"journal":{"name":"Journal of Physics-Energy","volume":" ","pages":""},"PeriodicalIF":6.9,"publicationDate":"2023-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44736040","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-12DOI: 10.1088/2515-7655/accc54
T. Hartnett, Kyungtae Lee, P. Balachandran
Rare-earth-free magnetostructural MnNiSi-based solid solutions are considered as promising candidates for solid-state cooling applications. In this paper, we use density functional theory calculations to study the energetics, variations in atomic displacements and bond length, and magnetic properties of high-entropic, intermetallic MnNi-X (X = Si0.2Ge0.2Sn0.2Al0.2Ga0.2) magnet in both the low-symmetry Pnma and high-symmetry P63/mmc structures, where we confine the large configurational entropy to the non-magnetic X-site of the compound. Our calculations reveal that the high-entropic chemical substitution of Si0.2Ge0.2Sn0.2Al0.2Ga0.2 in the X-site carry fingerprints that favor a reduction in magnetostructural transition temperature with minimal impact of total magnetization. These results motivate a promising path of high-entropic X-site substitutions to tune the magnetostructural properties of MnNiSi-based solid solutions.
{"title":"Density functional theory study of energetics, local chemical environment and magnetic properties in a high-entropic MnNiSi0.2Ge0.2Sn0.2Al0.2Ga0.2 intermetallic magnet","authors":"T. Hartnett, Kyungtae Lee, P. Balachandran","doi":"10.1088/2515-7655/accc54","DOIUrl":"https://doi.org/10.1088/2515-7655/accc54","url":null,"abstract":"Rare-earth-free magnetostructural MnNiSi-based solid solutions are considered as promising candidates for solid-state cooling applications. In this paper, we use density functional theory calculations to study the energetics, variations in atomic displacements and bond length, and magnetic properties of high-entropic, intermetallic MnNi-X (X = Si0.2Ge0.2Sn0.2Al0.2Ga0.2) magnet in both the low-symmetry Pnma and high-symmetry P63/mmc structures, where we confine the large configurational entropy to the non-magnetic X-site of the compound. Our calculations reveal that the high-entropic chemical substitution of Si0.2Ge0.2Sn0.2Al0.2Ga0.2 in the X-site carry fingerprints that favor a reduction in magnetostructural transition temperature with minimal impact of total magnetization. These results motivate a promising path of high-entropic X-site substitutions to tune the magnetostructural properties of MnNiSi-based solid solutions.","PeriodicalId":48500,"journal":{"name":"Journal of Physics-Energy","volume":" ","pages":""},"PeriodicalIF":6.9,"publicationDate":"2023-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47526961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-31DOI: 10.1088/2515-7655/acc972
Junning Li, A. Torelló, Y. Nouchokgwe, T. Granzow, V. Kovacova, S. Hirose, E. Defay
Electrocaloric (EC) materials, presenting large adiabatic temperature change or isothermal entropy change under the application (or removal) of electric fields, offer an efficient alternative to caloric heat pumps for replacing hazardous gases used in traditional vapor-compression systems. Recently, a large EC temperature change of 5.5 K have been reported in Pb(Sc0.5Ta0.5)O3 multilayer ceramic capacitors (Nair et al 2019 Nature 575 468) thanks to its strong first-order phase transition and a temperature span of 13 K has been reported in a prototype based on these capacitors (Torelló et al 2020 Science 370 125). However, the toxicity of lead forces researchers to find eco-friendly materials exhibiting competitive EC performances. Here, we study the EC effect in lead-free BaTiO3 multilayer capacitors using an infrared camera. Unlike commercial BaTiO3 capacitors, we prepared our samples without sacrifying the first-order phase transition in BaTiO3 while a low amount of 0.2 mol% Mn was added as an acceptor dopant to improve electrical resistivity. Their EC adiabatic temperature variations show two peaks versus temperature, which match BaTiO3 two first-order phase transitions, as observed by differential scanning calorimetry. We measured a temperature drop of ∼0.9 K over a temperature range of 70 K under 170 kV cm−1, starting at 30 °C near the tetragonal-to-orthorhombic phase transition. Under the same electric field, a maximum temperature change of 2.4 K was recorded at 126 °C, at BaTiO3’s Curie temperature. Our findings suggest that further optimized BaTiO3 capacitors could offer a path for designing lead-free caloric cooling prototypes.
{"title":"Electrocaloric effect in BaTiO3 multilayer capacitors with first-order phase transitions","authors":"Junning Li, A. Torelló, Y. Nouchokgwe, T. Granzow, V. Kovacova, S. Hirose, E. Defay","doi":"10.1088/2515-7655/acc972","DOIUrl":"https://doi.org/10.1088/2515-7655/acc972","url":null,"abstract":"Electrocaloric (EC) materials, presenting large adiabatic temperature change or isothermal entropy change under the application (or removal) of electric fields, offer an efficient alternative to caloric heat pumps for replacing hazardous gases used in traditional vapor-compression systems. Recently, a large EC temperature change of 5.5 K have been reported in Pb(Sc0.5Ta0.5)O3 multilayer ceramic capacitors (Nair et al 2019 Nature 575 468) thanks to its strong first-order phase transition and a temperature span of 13 K has been reported in a prototype based on these capacitors (Torelló et al 2020 Science 370 125). However, the toxicity of lead forces researchers to find eco-friendly materials exhibiting competitive EC performances. Here, we study the EC effect in lead-free BaTiO3 multilayer capacitors using an infrared camera. Unlike commercial BaTiO3 capacitors, we prepared our samples without sacrifying the first-order phase transition in BaTiO3 while a low amount of 0.2 mol% Mn was added as an acceptor dopant to improve electrical resistivity. Their EC adiabatic temperature variations show two peaks versus temperature, which match BaTiO3 two first-order phase transitions, as observed by differential scanning calorimetry. We measured a temperature drop of ∼0.9 K over a temperature range of 70 K under 170 kV cm−1, starting at 30 °C near the tetragonal-to-orthorhombic phase transition. Under the same electric field, a maximum temperature change of 2.4 K was recorded at 126 °C, at BaTiO3’s Curie temperature. Our findings suggest that further optimized BaTiO3 capacitors could offer a path for designing lead-free caloric cooling prototypes.","PeriodicalId":48500,"journal":{"name":"Journal of Physics-Energy","volume":" ","pages":""},"PeriodicalIF":6.9,"publicationDate":"2023-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47556837","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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