Pub Date : 2023-03-29DOI: 10.1088/2515-7655/acc892
G. Koutsourakis, C. Worsley, Michael Spence, J. Blakesley, T. Watson, M. Carnie, F. Castro
Metastability is a characteristic feature of perovskite solar cell (PSC) devices that affects power rating measurements and general electrical behaviour. In this work the metastability of different types of PSC devices is investigated through current–voltage (I–V) testing and voltage dependent photoluminescence (PL-V) imaging. We show that advanced I–V parameter acquisition methods need to be applied for accurate PSC performance evaluation, and that misleading results can be obtained when using simple fast I–V curves, which can lead to incorrect estimation of cell efficiency. The method, as applied in this work, can also distinguish between metastability and degradation, which is a crucial step towards reporting stabilised efficiencies of PSC devices. PL-V is then used to investigate temporal and spatial PL response at different voltage steps. In addition to the impact on current response, metastability effects are clearly observed in the spatial PL response of different types of PSCs. The results imply that a high density of local defects and non-uniformities leads to increased lateral metastability visible in PL-V measurements, which is directly linked to electrical metastability. This work indicates that existing quantitative PL imaging methods and point-based PL measurements of PSC devices may need to be revisited, as assumptions such as the absence of lateral currents or uniform voltage bias across a cell area may not be valid.
{"title":"Investigating spatial macroscopic metastability of perovskite solar cells with voltage dependent photoluminescence imaging","authors":"G. Koutsourakis, C. Worsley, Michael Spence, J. Blakesley, T. Watson, M. Carnie, F. Castro","doi":"10.1088/2515-7655/acc892","DOIUrl":"https://doi.org/10.1088/2515-7655/acc892","url":null,"abstract":"Metastability is a characteristic feature of perovskite solar cell (PSC) devices that affects power rating measurements and general electrical behaviour. In this work the metastability of different types of PSC devices is investigated through current–voltage (I–V) testing and voltage dependent photoluminescence (PL-V) imaging. We show that advanced I–V parameter acquisition methods need to be applied for accurate PSC performance evaluation, and that misleading results can be obtained when using simple fast I–V curves, which can lead to incorrect estimation of cell efficiency. The method, as applied in this work, can also distinguish between metastability and degradation, which is a crucial step towards reporting stabilised efficiencies of PSC devices. PL-V is then used to investigate temporal and spatial PL response at different voltage steps. In addition to the impact on current response, metastability effects are clearly observed in the spatial PL response of different types of PSCs. The results imply that a high density of local defects and non-uniformities leads to increased lateral metastability visible in PL-V measurements, which is directly linked to electrical metastability. This work indicates that existing quantitative PL imaging methods and point-based PL measurements of PSC devices may need to be revisited, as assumptions such as the absence of lateral currents or uniform voltage bias across a cell area may not be valid.","PeriodicalId":48500,"journal":{"name":"Journal of Physics-Energy","volume":" ","pages":""},"PeriodicalIF":6.9,"publicationDate":"2023-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43715674","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 : 2023-03-27DOI: 10.1088/2515-7655/acc7c8
G. Khandelwal, Swati Deswal, D. Shakthivel, R. Dahiya
The ever-increasing demand for energy as a result of the growing interest in applications, such as the Internet of Things and wearable systems, etc, calls for the development of self-sustained energy harvesting solutions. In this regard, 2D materials have sparked enormous interest recently, due to their outstanding properties, such as ultra-thin geometry, high electromechanical coupling, large surface area to volume ratio, tunable band gap, transparency and flexibility. This has given rise to noteworthy advancements in energy harvesters such as triboelectric nanogenerators (TENGs), piezoelectric nanogenerators (PENGs) and photovoltaics based on 2D materials. This review introduces the properties of different 2D materials including graphene, transition metal dichalcogenides, MXenes, black phosphorus, hexagonal boron nitride, metal-organic frameworks and covalent-organic frameworks. A detailed discussion of recent developments in 2D materials-based PENG, TENG and photovoltaic devices is included. The review also considers the performance enhancement mechanism and importance of 2D materials in energy harvesting. Finally, the challenges and future perspectives are laid out to present future research directions for the further development and extension of 2D materials-based energy harvesters.
{"title":"Recent developments in 2D materials for energy harvesting applications","authors":"G. Khandelwal, Swati Deswal, D. Shakthivel, R. Dahiya","doi":"10.1088/2515-7655/acc7c8","DOIUrl":"https://doi.org/10.1088/2515-7655/acc7c8","url":null,"abstract":"The ever-increasing demand for energy as a result of the growing interest in applications, such as the Internet of Things and wearable systems, etc, calls for the development of self-sustained energy harvesting solutions. In this regard, 2D materials have sparked enormous interest recently, due to their outstanding properties, such as ultra-thin geometry, high electromechanical coupling, large surface area to volume ratio, tunable band gap, transparency and flexibility. This has given rise to noteworthy advancements in energy harvesters such as triboelectric nanogenerators (TENGs), piezoelectric nanogenerators (PENGs) and photovoltaics based on 2D materials. This review introduces the properties of different 2D materials including graphene, transition metal dichalcogenides, MXenes, black phosphorus, hexagonal boron nitride, metal-organic frameworks and covalent-organic frameworks. A detailed discussion of recent developments in 2D materials-based PENG, TENG and photovoltaic devices is included. The review also considers the performance enhancement mechanism and importance of 2D materials in energy harvesting. Finally, the challenges and future perspectives are laid out to present future research directions for the further development and extension of 2D materials-based energy harvesters.","PeriodicalId":48500,"journal":{"name":"Journal of Physics-Energy","volume":" ","pages":""},"PeriodicalIF":6.9,"publicationDate":"2023-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46438834","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 : 2023-03-27DOI: 10.1088/2515-7655/acc4e9
Will Clarke, M. Wolf, Alison Walker, G. Richardson
We present a drift–diffusion model of a perovskite solar cell (PSC) in which carrier transport in the charge transport layers (TLs) is not based on the Boltzmann approximation to the Fermi–Dirac (FD) statistical distribution, in contrast to previously studied models. At sufficiently high carrier densities the Boltzmann approximation breaks down and the precise form of the density of states function (often assumed to be parabolic) has a significant influence on carrier transport. In particular, parabolic, Kane and Gaussian models of the density of states are discussed in depth and it is shown that the discrepancies between the Boltzmann approximation and the full FD statistical model are particularly marked for the Gaussian model, which is typically used to describe organic semiconducting TLs. Comparison is made between full device models, using parameter values taken from the literature, in which carrier motion in the TLs is described using (I) the full FD statistical model and (II) the Boltzmann approximation. For a representative TiO2/MAPI/Spiro device the behaviour of the PSC predicted by the Boltzmann-based model shows significant differences compared to that predicted by the FD-based model. This holds both at steady-state, where the Boltzmann treatment overestimates the power conversion efficiency by a factor of 27%, compared to the FD treatment, and in dynamic simulations of current–voltage hysteresis and electrochemical impedance spectroscopy. This suggests that the standard approach, in which carrier transport in the TLs is modelled based on the Boltzmann approximation, is inadequate. Furthermore, we show that the full FD treatment gives a more accurate representation of the steady-state performance, compared to the standard Boltzmann treatment, as measured against experimental data reported in the literature for typical TiO2/MAPI/Spiro devices.
{"title":"Charge transport modelling of perovskite solar cells accounting for non-Boltzmann statistics in organic and highly-doped transport layers","authors":"Will Clarke, M. Wolf, Alison Walker, G. Richardson","doi":"10.1088/2515-7655/acc4e9","DOIUrl":"https://doi.org/10.1088/2515-7655/acc4e9","url":null,"abstract":"We present a drift–diffusion model of a perovskite solar cell (PSC) in which carrier transport in the charge transport layers (TLs) is not based on the Boltzmann approximation to the Fermi–Dirac (FD) statistical distribution, in contrast to previously studied models. At sufficiently high carrier densities the Boltzmann approximation breaks down and the precise form of the density of states function (often assumed to be parabolic) has a significant influence on carrier transport. In particular, parabolic, Kane and Gaussian models of the density of states are discussed in depth and it is shown that the discrepancies between the Boltzmann approximation and the full FD statistical model are particularly marked for the Gaussian model, which is typically used to describe organic semiconducting TLs. Comparison is made between full device models, using parameter values taken from the literature, in which carrier motion in the TLs is described using (I) the full FD statistical model and (II) the Boltzmann approximation. For a representative TiO2/MAPI/Spiro device the behaviour of the PSC predicted by the Boltzmann-based model shows significant differences compared to that predicted by the FD-based model. This holds both at steady-state, where the Boltzmann treatment overestimates the power conversion efficiency by a factor of 27%, compared to the FD treatment, and in dynamic simulations of current–voltage hysteresis and electrochemical impedance spectroscopy. This suggests that the standard approach, in which carrier transport in the TLs is modelled based on the Boltzmann approximation, is inadequate. Furthermore, we show that the full FD treatment gives a more accurate representation of the steady-state performance, compared to the standard Boltzmann treatment, as measured against experimental data reported in the literature for typical TiO2/MAPI/Spiro devices.","PeriodicalId":48500,"journal":{"name":"Journal of Physics-Energy","volume":" ","pages":""},"PeriodicalIF":6.9,"publicationDate":"2023-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49456777","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 : 2023-03-23DOI: 10.1088/2515-7655/acc6ef
L. Mañosa, E. Stern-Taulats, A. Gràcia-Condal, A. Planes
Multiferroic materials with strong coupling between different degrees of freedom are prone to exhibit giant multicaloric effects resulting from the application or removal of diverse external fields. These materials exhibit a synergic response to the combined action of two fields when the monocaloric effects are both conventional (or both inverse), while a non-synergic response occurs when one of the monocaloric effects is conventional and the other is inverse. In all cases, the multicaloric properties (isothermal entropy and adiabatic temperature changes) do not result from the simple addition of the corresponding monocaloric quantities because there is a contribution from the interplay between degrees of freedom (cross-coupling term). In this paper, we analyse in detail the contribution of the cross-coupling term to the multicaloric entropy values obtained for both synergic and non-synergic multicaloric materials. We first introduce basic thermodynamic concepts accounting for the multicaloric effects, and next the contribution from the cross-coupling term is illustrated via several model examples. We finally analyse the realistic situation for two prototype materials with synergic and non-synergic multicaloric effects.
{"title":"Cross-coupling contribution to the isothermal entropy change in multicaloric materials","authors":"L. Mañosa, E. Stern-Taulats, A. Gràcia-Condal, A. Planes","doi":"10.1088/2515-7655/acc6ef","DOIUrl":"https://doi.org/10.1088/2515-7655/acc6ef","url":null,"abstract":"Multiferroic materials with strong coupling between different degrees of freedom are prone to exhibit giant multicaloric effects resulting from the application or removal of diverse external fields. These materials exhibit a synergic response to the combined action of two fields when the monocaloric effects are both conventional (or both inverse), while a non-synergic response occurs when one of the monocaloric effects is conventional and the other is inverse. In all cases, the multicaloric properties (isothermal entropy and adiabatic temperature changes) do not result from the simple addition of the corresponding monocaloric quantities because there is a contribution from the interplay between degrees of freedom (cross-coupling term). In this paper, we analyse in detail the contribution of the cross-coupling term to the multicaloric entropy values obtained for both synergic and non-synergic multicaloric materials. We first introduce basic thermodynamic concepts accounting for the multicaloric effects, and next the contribution from the cross-coupling term is illustrated via several model examples. We finally analyse the realistic situation for two prototype materials with synergic and non-synergic multicaloric effects.","PeriodicalId":48500,"journal":{"name":"Journal of Physics-Energy","volume":" ","pages":""},"PeriodicalIF":6.9,"publicationDate":"2023-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41451275","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 : 2023-03-23DOI: 10.1088/2515-7655/acc6f0
Frederic Rendell-Bhatti, M. Zeng, P. Lloveras, J. Tamarit, M. Barrio, E. Connolly, D. Maclaren, F. Johnson, L. Cohen, D. Boldrin
The magnetically frustrated manganese nitride antiperovskite family displays significant changes of entropy under changes in hydrostatic pressure near a first-order antiferromagnetic to paramagnetic phase transition that can be useful for the emerging field of solid-state barocaloric cooling. In previous studies, the transition hysteresis has significantly reduced the reversible barocaloric effects (BCE). Here we show that the transition hysteresis can be tailored through quaternary alloying in the Mn3Cu 1−x Sn x N system. We find the magnitude of hysteresis is minimised when Cu and Sn are equiatomic (x = 0.5) reaching values far less than previously found for Mn3 AN ( A= Pd, Ni, Ga, Zn), whilst retaining entropy changes of the same order of magnitude. These results demonstrate that reversible BCE are achievable for p < 100 MPa in the Mn3(A, B)N family and suggest routes to modify the transition properties in compounds of the same family.
在一阶反铁磁-顺磁相变附近的静水压力变化下，磁阻氮化锰反钙钛矿家族显示出显著的熵变化，这对于新兴的固态压热冷却领域是有用的。在以前的研究中，过渡滞后显著降低了可逆压热效应（BCE）。在这里，我们表明，在Mn3Cu 1−x Sn x N系统中，可以通过四元合金化来调整过渡磁滞。我们发现当Cu和Sn是等原子（x = 0.5）达到远小于先前发现的Mn3-AN（A=Pd、Ni、Ga、Zn）的值，同时保持相同数量级的熵变化。这些结果表明，对于p，可逆BCE是可以实现的 < 100MPa的Mn3（A，B）N族化合物中的过渡性质，并提出了改变同一族化合物中过渡性质的途径。
{"title":"Improving barocaloric properties by tailoring transition hysteresis in Mn3Cu 1−x Sn x N antiperovskites","authors":"Frederic Rendell-Bhatti, M. Zeng, P. Lloveras, J. Tamarit, M. Barrio, E. Connolly, D. Maclaren, F. Johnson, L. Cohen, D. Boldrin","doi":"10.1088/2515-7655/acc6f0","DOIUrl":"https://doi.org/10.1088/2515-7655/acc6f0","url":null,"abstract":"The magnetically frustrated manganese nitride antiperovskite family displays significant changes of entropy under changes in hydrostatic pressure near a first-order antiferromagnetic to paramagnetic phase transition that can be useful for the emerging field of solid-state barocaloric cooling. In previous studies, the transition hysteresis has significantly reduced the reversible barocaloric effects (BCE). Here we show that the transition hysteresis can be tailored through quaternary alloying in the Mn3Cu 1−x Sn x N system. We find the magnitude of hysteresis is minimised when Cu and Sn are equiatomic (x = 0.5) reaching values far less than previously found for Mn3 AN ( A= Pd, Ni, Ga, Zn), whilst retaining entropy changes of the same order of magnitude. These results demonstrate that reversible BCE are achievable for p < 100 MPa in the Mn3(A, B)N family and suggest routes to modify the transition properties in compounds of the same family.","PeriodicalId":48500,"journal":{"name":"Journal of Physics-Energy","volume":" ","pages":""},"PeriodicalIF":6.9,"publicationDate":"2023-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49178469","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 : 2023-03-22DOI: 10.1088/2515-7655/acc68d
Huidi Yu, Xu Jin, Yiheng Li, Lin Zhang, Meng Yang, Jianming Li
Water electrolysis has attracted significant attention for large-scale production of green hydrogen as next-generation clean fuels. Recently, the development of graphdiyne (GDY), a new member of carbon allotropes, has been promisingly offering novel alternatives for acquisition of inexpensive and efficient catalysts in the water electrolyzer. The unique atomic arrangement in GDY architecture leads to coexistence of sp– and sp2–C, correspondingly brings numerous intriguing features such as heterogeneous electron distribution, wide tailorable natural bandgap, rapid electron/mass transport and rich chemical bonds. These unique intrinsic natures of GDY provide brilliant inspirations for scientists to design new-concept electrocatalyst toward cathodic hydrogen evolution reaction, anodic oxygen evolution reaction and the overall water-splitting. Based on the immense progress, in this short perspective, current principal design strategies of GDY-based catalysts are systematically summarized, including interface engineering, individual atom fixation, induced constrained growth and bottom-up fabrication. With abundant implementation examples for achieving highly efficient water electrolysis, in particular we focus on clarifying the decisive role of GDY on these design strategies with comprehensive theoretical and experimental evidences. The future direction in developing GDY-based electrocatalysts in hydrogen energy field is also depicted with the urgent anticipation of deeper understanding of structure-performance relationship and catalytic mechanism, especially those in real industry water electrolyzers.
{"title":"Principal strategies for designing graphdiyne-based catalyst toward green hydrogen production from water electrolysis","authors":"Huidi Yu, Xu Jin, Yiheng Li, Lin Zhang, Meng Yang, Jianming Li","doi":"10.1088/2515-7655/acc68d","DOIUrl":"https://doi.org/10.1088/2515-7655/acc68d","url":null,"abstract":"Water electrolysis has attracted significant attention for large-scale production of green hydrogen as next-generation clean fuels. Recently, the development of graphdiyne (GDY), a new member of carbon allotropes, has been promisingly offering novel alternatives for acquisition of inexpensive and efficient catalysts in the water electrolyzer. The unique atomic arrangement in GDY architecture leads to coexistence of sp– and sp2–C, correspondingly brings numerous intriguing features such as heterogeneous electron distribution, wide tailorable natural bandgap, rapid electron/mass transport and rich chemical bonds. These unique intrinsic natures of GDY provide brilliant inspirations for scientists to design new-concept electrocatalyst toward cathodic hydrogen evolution reaction, anodic oxygen evolution reaction and the overall water-splitting. Based on the immense progress, in this short perspective, current principal design strategies of GDY-based catalysts are systematically summarized, including interface engineering, individual atom fixation, induced constrained growth and bottom-up fabrication. With abundant implementation examples for achieving highly efficient water electrolysis, in particular we focus on clarifying the decisive role of GDY on these design strategies with comprehensive theoretical and experimental evidences. The future direction in developing GDY-based electrocatalysts in hydrogen energy field is also depicted with the urgent anticipation of deeper understanding of structure-performance relationship and catalytic mechanism, especially those in real industry water electrolyzers.","PeriodicalId":48500,"journal":{"name":"Journal of Physics-Energy","volume":" ","pages":""},"PeriodicalIF":6.9,"publicationDate":"2023-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47054697","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 : 2023-03-20DOI: 10.1088/2515-7655/acc5b1
Silvère Panisset, M. Burriel, J. Laurencin, D. Jauffrès
Numerical models are versatile tools to study and predict efficiently the performance of solid oxide cells (SOCs) according to their microstructure and composition. As the main contribution to the cell polarisation is due to the oxygen electrode, a large part of the proposed models has been focused on this electrode. Electrode modelling aims to improve the SOCs performance by serving as a guide for the microstructural optimisation, and helps to better understand the electrochemical reaction mechanisms. For studying the electrode microstructure, three categories of models can be distinguished: homogenised models, simplified geometry based models, and reconstructed microstructure based models. Most models are based on continuum physics, while elementary kinetic models have been developed more recently. This article presents a review of the existing SOCs models for the oxygen electrode. As a perspective, the current challenges of electrode modelling are discussed in views of a better prediction of the performance and durability, and more specifically for the case of thin-film SOCs.
{"title":"Modelling of solid oxide cell oxygen electrodes","authors":"Silvère Panisset, M. Burriel, J. Laurencin, D. Jauffrès","doi":"10.1088/2515-7655/acc5b1","DOIUrl":"https://doi.org/10.1088/2515-7655/acc5b1","url":null,"abstract":"Numerical models are versatile tools to study and predict efficiently the performance of solid oxide cells (SOCs) according to their microstructure and composition. As the main contribution to the cell polarisation is due to the oxygen electrode, a large part of the proposed models has been focused on this electrode. Electrode modelling aims to improve the SOCs performance by serving as a guide for the microstructural optimisation, and helps to better understand the electrochemical reaction mechanisms. For studying the electrode microstructure, three categories of models can be distinguished: homogenised models, simplified geometry based models, and reconstructed microstructure based models. Most models are based on continuum physics, while elementary kinetic models have been developed more recently. This article presents a review of the existing SOCs models for the oxygen electrode. As a perspective, the current challenges of electrode modelling are discussed in views of a better prediction of the performance and durability, and more specifically for the case of thin-film SOCs.","PeriodicalId":48500,"journal":{"name":"Journal of Physics-Energy","volume":" ","pages":""},"PeriodicalIF":6.9,"publicationDate":"2023-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44105603","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 : 2023-03-20DOI: 10.1088/2515-7655/acc5b2
Yuya Kawarada, A. Aimi, A. Santos, Gentaro Nakata, I. Takeuchi, K. Fujimoto
Cu-based superelastic shape memory alloys are promising for low-stress elastocaloric cooling. We have synthesized bulk alloys of 68Cu–16Al–16Zn under different conditions in order to promote its grain growth and enhance its elastocaloric properties. High-temperature x-ray diffraction of untreated 68Cu–16Al–16Zn alloy showed that the phase boundary between the α + β mixed phases and the high temperature phase (β phase) was between 973 K and 1023 K. Based on this result, the 68Cu–16Al–16Zn alloy was heated and cooled in a furnace repeatedly between 773 K and 1173 K. The maximum grain size after heat treatment of the ingot rolled to 67% reached 11.1 mm. The latent heat of the martensitic transformation after grain growth was 6.3 J g−1, which is higher than the previously reported value for the compound. The stress–strain curve of 68Cu–16Al–16Zn rolled to 67% rolling with cyclical heat treatments showed a maximum stress of 106 MPa at 4.5% strain, with adiabatic temperature change of 5.9 K in heating during stress loading and 5.6 K in cooling in stress removal. Furthermore, no fatigue in the stress–strain behavior was observed up to at least 60 000 mechanical cycles at 2% strain.
{"title":"Abnormal grain growth of 68Cu–16Al–16Zn alloys for elastocaloric cooling via cyclical heat treatments","authors":"Yuya Kawarada, A. Aimi, A. Santos, Gentaro Nakata, I. Takeuchi, K. Fujimoto","doi":"10.1088/2515-7655/acc5b2","DOIUrl":"https://doi.org/10.1088/2515-7655/acc5b2","url":null,"abstract":"Cu-based superelastic shape memory alloys are promising for low-stress elastocaloric cooling. We have synthesized bulk alloys of 68Cu–16Al–16Zn under different conditions in order to promote its grain growth and enhance its elastocaloric properties. High-temperature x-ray diffraction of untreated 68Cu–16Al–16Zn alloy showed that the phase boundary between the α + β mixed phases and the high temperature phase (β phase) was between 973 K and 1023 K. Based on this result, the 68Cu–16Al–16Zn alloy was heated and cooled in a furnace repeatedly between 773 K and 1173 K. The maximum grain size after heat treatment of the ingot rolled to 67% reached 11.1 mm. The latent heat of the martensitic transformation after grain growth was 6.3 J g−1, which is higher than the previously reported value for the compound. The stress–strain curve of 68Cu–16Al–16Zn rolled to 67% rolling with cyclical heat treatments showed a maximum stress of 106 MPa at 4.5% strain, with adiabatic temperature change of 5.9 K in heating during stress loading and 5.6 K in cooling in stress removal. Furthermore, no fatigue in the stress–strain behavior was observed up to at least 60 000 mechanical cycles at 2% strain.","PeriodicalId":48500,"journal":{"name":"Journal of Physics-Energy","volume":" ","pages":""},"PeriodicalIF":6.9,"publicationDate":"2023-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49023720","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 : 2023-03-16DOI: 10.1088/2515-7655/acc4e7
T. Shockner, O. Zada, S. Goldenshluger, G. Ziskind
The growing interest in phase-change materials (PCM) is related to their possible role in thermal energy storage and thermal management. The choice of materials depends strongly on the required temperature range, whereas the latent heat of solid–liquid phase transition has to be as high as possible. Among other organic PCM, sugar alcohols have gained some attention due to their availability and certain advantageous properties. However, the thermal processes in these materials still require investigation. In the present work, we focused on the materials with solid–liquid phase change within 80 °C–100 °C. A comprehensive literature survey was conducted to elucidate the available sugar alcohols relevant to this range. It was found that the use of pure materials of this type is not very practical, because of their scarcity in the required range and their specific features, like difficulties with crystallization and solidification. On the other hand, based on the literature, we have discerned three eutectic mixtures of erythritol with other organic materials, namely, erythritol–xylitol, erythritol–urea and erythritol– trimethylolethane (TME). In all those cases, it is remarkable that while the components commonly have rather high melting temperatures, the eutectic mixtures had the phase transitions in the required range. Still, each of these mixtures has its own peculiar features, especially at cooling and solidification. An extensive experimental study was performed to provide detailed visualization of these major processes. The results revealed the melting temperature and latent heat of the mixtures to be: 84 °C and 190 J g−1 for erythritol–xylitol, 82 °C and 227 J g−1 for erythritol–urea. Erythritol–TME has two phase transitions at 82 °C and 97 °C, with total latent heat of 198 J g−1. Based on the present findings, the erythritol–urea mixture is the best PCM candidate for the melting range within 80 °C–100 °C.
{"title":"Investigation of high-enthalpy organic phase-change materials for heat storage and thermal management","authors":"T. Shockner, O. Zada, S. Goldenshluger, G. Ziskind","doi":"10.1088/2515-7655/acc4e7","DOIUrl":"https://doi.org/10.1088/2515-7655/acc4e7","url":null,"abstract":"The growing interest in phase-change materials (PCM) is related to their possible role in thermal energy storage and thermal management. The choice of materials depends strongly on the required temperature range, whereas the latent heat of solid–liquid phase transition has to be as high as possible. Among other organic PCM, sugar alcohols have gained some attention due to their availability and certain advantageous properties. However, the thermal processes in these materials still require investigation. In the present work, we focused on the materials with solid–liquid phase change within 80 °C–100 °C. A comprehensive literature survey was conducted to elucidate the available sugar alcohols relevant to this range. It was found that the use of pure materials of this type is not very practical, because of their scarcity in the required range and their specific features, like difficulties with crystallization and solidification. On the other hand, based on the literature, we have discerned three eutectic mixtures of erythritol with other organic materials, namely, erythritol–xylitol, erythritol–urea and erythritol– trimethylolethane (TME). In all those cases, it is remarkable that while the components commonly have rather high melting temperatures, the eutectic mixtures had the phase transitions in the required range. Still, each of these mixtures has its own peculiar features, especially at cooling and solidification. An extensive experimental study was performed to provide detailed visualization of these major processes. The results revealed the melting temperature and latent heat of the mixtures to be: 84 °C and 190 J g−1 for erythritol–xylitol, 82 °C and 227 J g−1 for erythritol–urea. Erythritol–TME has two phase transitions at 82 °C and 97 °C, with total latent heat of 198 J g−1. Based on the present findings, the erythritol–urea mixture is the best PCM candidate for the melting range within 80 °C–100 °C.","PeriodicalId":48500,"journal":{"name":"Journal of Physics-Energy","volume":" ","pages":""},"PeriodicalIF":6.9,"publicationDate":"2023-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47663336","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 : 2023-03-16DOI: 10.1088/2515-7655/acc4e8
Rouzbeh Ramezani, L. Felice, F. Gallucci
Faced with increasingly serious energy and global warming, it is critical to put forward an alternative non-carbonaceous fuel. In this regard, hydrogen appears as the ultimate clean fuel for power and heat generation, and as an important feedstock for various chemical and petrochemical industries. The chemical looping reforming (CLR) concept, is an emerging technique for the conversion of hydrocarbon fuels into high-quality hydrogen via the circulation of oxygen carriers which allows a decrease in CO2 emissions. In this review, a comprehensive evaluation and recent progress in glycerol, ethanol and methane reforming for hydrogen production are presented. The key elements for a successful CLR process are studied and the technical challenges to achieve high-purity hydrogen along with the possible solutions are also assessed. As product quality, cost and the overall efficiency of the process can be influenced by the oxygen carrier materials used, noteworthy attention is given to the most recent development in this field. The use of Ni, Fe, Cu, Ce, Mn and Co-based material as potential oxygen carriers under different experimental conditions for hydrogen generation from different feedstock by CLR is discussed. Furthermore, the recent research conducted on the sorption-enhanced reforming process is reviewed and the performance of the various type of CO2 sorbents such as CaO, Li2ZrO3 and MgO is highlighted.
{"title":"A review of chemical looping reforming technologies for hydrogen production: recent advances and future challenges","authors":"Rouzbeh Ramezani, L. Felice, F. Gallucci","doi":"10.1088/2515-7655/acc4e8","DOIUrl":"https://doi.org/10.1088/2515-7655/acc4e8","url":null,"abstract":"Faced with increasingly serious energy and global warming, it is critical to put forward an alternative non-carbonaceous fuel. In this regard, hydrogen appears as the ultimate clean fuel for power and heat generation, and as an important feedstock for various chemical and petrochemical industries. The chemical looping reforming (CLR) concept, is an emerging technique for the conversion of hydrocarbon fuels into high-quality hydrogen via the circulation of oxygen carriers which allows a decrease in CO2 emissions. In this review, a comprehensive evaluation and recent progress in glycerol, ethanol and methane reforming for hydrogen production are presented. The key elements for a successful CLR process are studied and the technical challenges to achieve high-purity hydrogen along with the possible solutions are also assessed. As product quality, cost and the overall efficiency of the process can be influenced by the oxygen carrier materials used, noteworthy attention is given to the most recent development in this field. The use of Ni, Fe, Cu, Ce, Mn and Co-based material as potential oxygen carriers under different experimental conditions for hydrogen generation from different feedstock by CLR is discussed. Furthermore, the recent research conducted on the sorption-enhanced reforming process is reviewed and the performance of the various type of CO2 sorbents such as CaO, Li2ZrO3 and MgO is highlighted.","PeriodicalId":48500,"journal":{"name":"Journal of Physics-Energy","volume":" ","pages":""},"PeriodicalIF":6.9,"publicationDate":"2023-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44269888","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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