Sunesh S. Mani, Sivaraj Rajendran, Thomas Mathew and Chinnakonda S. Gopinath
The major issues that determine the efficiency of photocatalyst composite materials for solar hydrogen production, with or without a sacrificial agent, are efficient visible light harvesting properties, efficient separation of charge carriers and their utilization of redox sites, and stability. Thus, significant efforts have been devoted in the past few decades to modify the above characteristics by integrating constituent components of composites using different approaches. In the present review, we aim to summarize the recent advances, predominantly, in the area of TiO2-based photocatalyst composites for solar hydrogen production. Firstly, we present the recent progress in material integration aspects by discussing the integration of TiO2 with different categories of materials, including noble/3d metals, metal oxides/sulphides/selenides, other low bandgap semiconductors, C-based materials, and dye sensitizers. Furthermore, we discuss how material integration helps in tailoring the electronic and optical properties for activity tuning in solar H2 production. Subsequently, critical changes in the physico-chemical and electronic properties of composites with respect to their preparation methods, morphology, crystallographic facets, particle size, dopant, calcination temperature, and structure–activity relationship to solar hydrogen production are addressed in detail. Moreover, we discuss the importance of fabricating a photocatalyst in a thin film form and performing solar hydrogen production in different reactor set-ups for enhancing its photocatalytic performance, while addressing device scalability. Despite the significant advancements made in this field, solar-to-hydrogen conversion efficiency still needs to be improved to realise the practical application of solar hydrogen production. In this case, the direct conversion of water to hydrogen via overall water splitting and renewable H2 production from wastewater or biomass components by employing suitable photocatalysts are some possible ways to improve the energy efficiency, and continuous research in the above directions is highly desirable.
{"title":"A review on the recent advances in the design and structure–activity relationship of TiO2-based photocatalysts for solar hydrogen production","authors":"Sunesh S. Mani, Sivaraj Rajendran, Thomas Mathew and Chinnakonda S. Gopinath","doi":"10.1039/D4YA00249K","DOIUrl":"10.1039/D4YA00249K","url":null,"abstract":"<p >The major issues that determine the efficiency of photocatalyst composite materials for solar hydrogen production, with or without a sacrificial agent, are efficient visible light harvesting properties, efficient separation of charge carriers and their utilization of redox sites, and stability. Thus, significant efforts have been devoted in the past few decades to modify the above characteristics by integrating constituent components of composites using different approaches. In the present review, we aim to summarize the recent advances, predominantly, in the area of TiO<small><sub>2</sub></small>-based photocatalyst composites for solar hydrogen production. Firstly, we present the recent progress in material integration aspects by discussing the integration of TiO<small><sub>2</sub></small> with different categories of materials, including noble/3d metals, metal oxides/sulphides/selenides, other low bandgap semiconductors, C-based materials, and dye sensitizers. Furthermore, we discuss how material integration helps in tailoring the electronic and optical properties for activity tuning in solar H<small><sub>2</sub></small> production. Subsequently, critical changes in the physico-chemical and electronic properties of composites with respect to their preparation methods, morphology, crystallographic facets, particle size, dopant, calcination temperature, and structure–activity relationship to solar hydrogen production are addressed in detail. Moreover, we discuss the importance of fabricating a photocatalyst in a thin film form and performing solar hydrogen production in different reactor set-ups for enhancing its photocatalytic performance, while addressing device scalability. Despite the significant advancements made in this field, solar-to-hydrogen conversion efficiency still needs to be improved to realise the practical application of solar hydrogen production. In this case, the direct conversion of water to hydrogen <em>via</em> overall water splitting and renewable H<small><sub>2</sub></small> production from wastewater or biomass components by employing suitable photocatalysts are some possible ways to improve the energy efficiency, and continuous research in the above directions is highly desirable.</p>","PeriodicalId":72913,"journal":{"name":"Energy advances","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2024-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/ya/d4ya00249k?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141507495","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Krämer, J. Hopster, A. Windmüller, R.-A. Eichel, M. Grünebaum, T. Jüstel, M. Winter and K. Neuhaus
In this work, the suitability of the spinel material ZnFe2O4, which has already been widely investigated in the context of its magnetic and photocatalytic properties, for use as active material for the cathode side in zinc ion batteries is presented. In addition to pure ZnFe2O4, part of the Fe3+ was doped with Ti4+ to achieve stabilization of Zn vacancies in the material and increase ionic conductivity as indicated by previous modelling results. Ceramic samples with the composition ZnFe2−xTixO4 (x = 0 to 0.25) were prepared via a Pechini synthesis route and investigated regarding their optical, structural and electrochemical characteristics. It has been successfully demonstrated that both pure and Ti doped ZnFe2O4 can be used as active material in the positive electrodes of zinc metal batteries or in an “anode-free” setup with Sn metal. Cells with calcined ZnFe2xTixO4 (x = 0.09)|0.5 M zinc triflate in acetonitrile|Zn showed a stable cycling behavior over 1000 cycles and an average initial specific capacity of 55 mA h g−1.
这项研究介绍了尖晶石材料 ZnFe2O4 作为锌离子电池阴极活性材料的适用性,这种材料的磁性和光催化特性已得到广泛研究。除纯 ZnFe2O4 外,部分 Fe3+ 还掺杂了 Ti4+,以稳定材料中的 Zn 空位,并提高离子导电性,这与之前的建模结果一致。通过 Pechini 合成路线制备了成分为 ZnFe2-xTixO4(x = 0 至 0.25)的陶瓷样品,并对其光学、结构和电化学特性进行了研究。研究成功证明,纯 ZnFe2O4 和掺杂 Ti 的 ZnFe2O4 均可用作锌金属电池正极的活性材料,或与锡金属一起用于 "无阳极 "设置。使用煅烧 ZnFe2xTixO4 (x = 0.09)|0.5 M 三酸锌乙腈|Zn 的电池在 1000 次循环中表现出稳定的循环行为,平均初始比容量为 55 mA h g-1。
{"title":"Teaching an old dog new tricks: Ti-doped ZnFe2O4 as active material in zinc ion batteries – a proof of concept†","authors":"S. Krämer, J. Hopster, A. Windmüller, R.-A. Eichel, M. Grünebaum, T. Jüstel, M. Winter and K. Neuhaus","doi":"10.1039/D4YA00134F","DOIUrl":"10.1039/D4YA00134F","url":null,"abstract":"<p >In this work, the suitability of the spinel material ZnFe<small><sub>2</sub></small>O<small><sub>4</sub></small>, which has already been widely investigated in the context of its magnetic and photocatalytic properties, for use as active material for the cathode side in zinc ion batteries is presented. In addition to pure ZnFe<small><sub>2</sub></small>O<small><sub>4</sub></small>, part of the Fe<small><sup>3+</sup></small> was doped with Ti<small><sup>4+</sup></small> to achieve stabilization of Zn vacancies in the material and increase ionic conductivity as indicated by previous modelling results. Ceramic samples with the composition ZnFe<small><sub>2−<em>x</em></sub></small>Ti<small><sub><em>x</em></sub></small>O<small><sub>4</sub></small> (<em>x</em> = 0 to 0.25) were prepared <em>via</em> a Pechini synthesis route and investigated regarding their optical, structural and electrochemical characteristics. It has been successfully demonstrated that both pure and Ti doped ZnFe<small><sub>2</sub></small>O<small><sub>4</sub></small> can be used as active material in the positive electrodes of zinc metal batteries or in an “anode-free” setup with Sn metal. Cells with calcined ZnFe<small><sub>2<em>x</em></sub></small>Ti<small><sub><em>x</em></sub></small>O<small><sub>4</sub></small> (<em>x</em> = 0.09)|0.5 M zinc triflate in acetonitrile|Zn showed a stable cycling behavior over 1000 cycles and an average initial specific capacity of 55 mA h g<small><sup>−1</sup></small>.</p>","PeriodicalId":72913,"journal":{"name":"Energy advances","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2024-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/ya/d4ya00134f?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141512419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Niklas Weber, Sebastian Schuhmann, Robert Löwe, Jens Tübke and Hermann Nirschl
Lithium-ion batteries produce a vast amount of gases during decomposition reactions and thermal runaway. While the amount and composition of these gases has been investigated in the past, little is known about their impact on thermal transport inside the battery cell. Especially for pouch cells, which do not have a rigid housing, this becomes even more important in multi-cell scenarios since thermal propagation is governed by heat transfer. In this work, a simulation framework is presented that enhances the chemical single cell model by accounting for these thermal transport changes in gas producing pouch cells. It is validated by performing two battery cell propagation experiments in an autoclave. Besides the temperature measurement, the propagation time between the cells and the gas composition are analyzed and compared between simulation and experiment. Further, it is investigated how the application of an external pressing force impacts the heat transfer and thus the propagation behavior. In the given setup, the propagation time decreased from 37.2 s to 16.8 s with increasing pressing force.
{"title":"On the effect of gas generation on heat transfer during thermal runaway of pouch cells","authors":"Niklas Weber, Sebastian Schuhmann, Robert Löwe, Jens Tübke and Hermann Nirschl","doi":"10.1039/D4YA00205A","DOIUrl":"10.1039/D4YA00205A","url":null,"abstract":"<p >Lithium-ion batteries produce a vast amount of gases during decomposition reactions and thermal runaway. While the amount and composition of these gases has been investigated in the past, little is known about their impact on thermal transport inside the battery cell. Especially for pouch cells, which do not have a rigid housing, this becomes even more important in multi-cell scenarios since thermal propagation is governed by heat transfer. In this work, a simulation framework is presented that enhances the chemical single cell model by accounting for these thermal transport changes in gas producing pouch cells. It is validated by performing two battery cell propagation experiments in an autoclave. Besides the temperature measurement, the propagation time between the cells and the gas composition are analyzed and compared between simulation and experiment. Further, it is investigated how the application of an external pressing force impacts the heat transfer and thus the propagation behavior. In the given setup, the propagation time decreased from 37.2 s to 16.8 s with increasing pressing force.</p>","PeriodicalId":72913,"journal":{"name":"Energy advances","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2024-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/ya/d4ya00205a?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141512423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dipayan Mondal, Ishita Naskar, Melepurath Deepa and Ashutosh Kumar Mishra
With the increasing interest in incorporating redox-active organic molecules as potential materials in energy storage systems, we envisaged a chemical design of a naturally occurring redox-active flavin moiety. Herein, we report the fabrication and characterization of asymmetric supercapacitors (ASCs) based on modified flavins as cathode materials. Notably, subtle chemical modification with the incorporation of a carboxylic functionality around the flavin core (cFl) was found to impart superior ion-storage properties compared to a simple flavin derivative (Fl). As determined, the specific capacitance (SC) for cFl and Fl as individual electrodes was found to be 170 and 62 F g−1, respectively, whereas in a two electrode ASC with activated carbon serving as the anode, the SC was found to be 107 and 29 F g−1, respectively, at a current density of 1.25 A g−1. With better cycling stability (retaining 87% of its initial SC in the case of cFl) and significantly higher energy density (38 W h kg−1 for cFl) as compared to most of the known organic material-based electrodes, the modified flavin derivatives serve as better organic electrode alternatives for practical energy storage applications.
随着人们对将氧化还原活性有机分子作为储能系统潜在材料的兴趣日益浓厚,我们设想了一种围绕天然氧化还原活性黄素分子的化学设计。在此,我们报告了基于改性黄素阴极材料的不对称超级电容器(ASCs)的制造和表征。值得注意的是,与简单的黄素衍生物(Fl)相比,通过在黄素核心(cFl)周围加入羧基官能团进行微妙的化学修饰,可赋予其卓越的离子存储特性。经测定,作为单独电极的 cFl 和 Fl 的比电容(SC)分别为 170 和 62 F g-1;而在以活性炭为阳极的双电极 ASCs 中,电流密度为 1.25 A g-1 时,比电容(SC)分别为 107 和 29 F g-1。与大多数已知的基于有机材料的电极相比,改性黄素衍生物具有更好的循环稳定性(cFl 可保持 94% 的初始 SC)和更高的能量密度(cFl 可保持 38 Wh kg-1),是实际储能应用中更好的有机电极替代品。
{"title":"Bioinspired flavin analogues as organic electrode materials for supercapacitor applications†","authors":"Dipayan Mondal, Ishita Naskar, Melepurath Deepa and Ashutosh Kumar Mishra","doi":"10.1039/D4YA00001C","DOIUrl":"10.1039/D4YA00001C","url":null,"abstract":"<p >With the increasing interest in incorporating redox-active organic molecules as potential materials in energy storage systems, we envisaged a chemical design of a naturally occurring redox-active flavin moiety. Herein, we report the fabrication and characterization of asymmetric supercapacitors (ASCs) based on modified flavins as cathode materials. Notably, subtle chemical modification with the incorporation of a carboxylic functionality around the flavin core (<strong><em>c</em>Fl</strong>) was found to impart superior ion-storage properties compared to a simple flavin derivative (<strong>Fl</strong>). As determined, the specific capacitance (SC) for <strong><em>c</em>Fl</strong> and <strong>Fl</strong> as individual electrodes was found to be 170 and 62 F g<small><sup>−1</sup></small>, respectively, whereas in a two electrode ASC with activated carbon serving as the anode, the SC was found to be 107 and 29 F g<small><sup>−1</sup></small>, respectively, at a current density of 1.25 A g<small><sup>−1</sup></small>. With better cycling stability (retaining 87% of its initial SC in the case of <strong><em>c</em>Fl</strong>) and significantly higher energy density (38 W h kg<small><sup>−1</sup></small> for <strong><em>c</em>Fl</strong>) as compared to most of the known organic material-based electrodes, the modified flavin derivatives serve as better organic electrode alternatives for practical energy storage applications.</p>","PeriodicalId":72913,"journal":{"name":"Energy advances","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2024-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/ya/d4ya00001c?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141254001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
α-Pinene and isobutene/isobutane can undergo hybrid alkylation under acid catalysis, resulting in C14 and C20 product fractions with favorable bio-based high-energy-density fuel properties after hydrogenation. In this study, the catalytic performance of zeolite molecular sieves, such as Hβ, HY, HZSM-5, HZSM-35, HSAPO-11, was investigated for the alkylation of α-pinene and Isobut-5 (a mixture of isobutene/isobutane with a mass ratio of 1 : 5) given the acidic sites and specific pore structures with shape-selective abilities of zeolite catalysts. Various characterization techniques, including temperature-programmed desorption of ammonia (NH3-TPD), Fourier transform infrared spectroscopy with pyridine adsorption (Py-IR), N2 adsorption/desorption, X-ray fluorescence spectrum (XRF), and particle size analysis, were conducted to analyze the acidic properties, pore characteristics, silica–aluminum ratio, and grain size of the zeolites, and their influence on the alkylation of α-pinene and Isobut-5. Moreover, the recycling performance of the favorite Hβ-25n catalyst and an effective regeneration method were investigated using temperature-programmed oxidation (TPO) analysis. This study provides essential research data for the preparation of α-pinene-based high-energy-density fuels.
{"title":"Alkylation of α-pinene with isobutene/isobutane over Hβ zeolite†","authors":"Zhaocai Jiao, Mingzu Liu, Ningbo Yang, Fengli Yu, Congxia Xie, Shitao Yu and Bing Yuan","doi":"10.1039/D4YA00291A","DOIUrl":"10.1039/D4YA00291A","url":null,"abstract":"<p >α-Pinene and isobutene/isobutane can undergo hybrid alkylation under acid catalysis, resulting in C<small><sub>14</sub></small> and C<small><sub>20</sub></small> product fractions with favorable bio-based high-energy-density fuel properties after hydrogenation. In this study, the catalytic performance of zeolite molecular sieves, such as Hβ, HY, HZSM-5, HZSM-35, HSAPO-11, was investigated for the alkylation of α-pinene and Isobut-5 (a mixture of isobutene/isobutane with a mass ratio of 1 : 5) given the acidic sites and specific pore structures with shape-selective abilities of zeolite catalysts. Various characterization techniques, including temperature-programmed desorption of ammonia (NH<small><sub>3</sub></small>-TPD), Fourier transform infrared spectroscopy with pyridine adsorption (Py-IR), N<small><sub>2</sub></small> adsorption/desorption, X-ray fluorescence spectrum (XRF), and particle size analysis, were conducted to analyze the acidic properties, pore characteristics, silica–aluminum ratio, and grain size of the zeolites, and their influence on the alkylation of α-pinene and Isobut-5. Moreover, the recycling performance of the favorite Hβ-25n catalyst and an effective regeneration method were investigated using temperature-programmed oxidation (TPO) analysis. This study provides essential research data for the preparation of α-pinene-based high-energy-density fuels.</p>","PeriodicalId":72913,"journal":{"name":"Energy advances","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2024-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/ya/d4ya00291a?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141254239","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dina G. Boer, Henk H. van de Bovenkamp, Jort Langerak, Benny Bakker and Paolo P. Pescarmona
Biogas upgrading by selective adsorption of CO2 using vacuum pressure swing adsorption (VPSA) is a technology that can enable the utilization of the isolated biomethane as a direct replacement for natural gas. In this work, we report for the first time the investigation of LTA and SAPO-34 macroscopic beads with hierarchical porosity as CO2 adsorbents in a VPSA setup. While a binder is generally required to shape zeolites and zeotypes into the macroscopic format (e.g. beads, pellets) needed for application in a VPSA column, in this work binderless LTA and SAPO-34 beads were studied and compared with commercial binder-containing zeolite 4A beads. Binary breakthrough experiments were conducted with a gas mixture mimicking biogas (i.e. 40 vol% CO2 and 60 vol% CH4) in a single adsorption column up to 4 bar. The SAPO-34 beads displayed a slightly steeper breakthrough with less significant tailing compared to the LTA beads, which was ascribed to faster intra-crystalline diffusion due to the different framework structure and the lower adsorption strength of CO2 on SAPO-34 compared to LTA. Notably, both the binderless LTA and SAPO-34 beads displayed a slightly sharper breakthrough and less significant tailing compared to commercial 4A beads. This was attributed to the open and accessible hierarchical pore structure of the binderless beads. The CO2 adsorption capacity for the SAPO-34 beads was relatively stable over 5 cycles, while the LTA and commercial 4A beads displayed a significant decrease in adsorption capacity from the first to the second cycle. For the SAPO-34 beads, a cyclic adsorption capacity at breakthrough around 2 mmol g−1 and a CO2 productivity > 3 mol kg−1 h−1 were achieved. These values are significantly higher than those of the LTA and commercial 4A beads, making the SAPO-34 beads a promising candidate for industrial application in VPSA.
{"title":"Evaluation of binderless LTA and SAPO-34 beads as CO2 adsorbents for biogas upgrading in a vacuum pressure swing adsorption setup†","authors":"Dina G. Boer, Henk H. van de Bovenkamp, Jort Langerak, Benny Bakker and Paolo P. Pescarmona","doi":"10.1039/D4YA00007B","DOIUrl":"10.1039/D4YA00007B","url":null,"abstract":"<p >Biogas upgrading by selective adsorption of CO<small><sub>2</sub></small> using vacuum pressure swing adsorption (VPSA) is a technology that can enable the utilization of the isolated biomethane as a direct replacement for natural gas. In this work, we report for the first time the investigation of LTA and SAPO-34 macroscopic beads with hierarchical porosity as CO<small><sub>2</sub></small> adsorbents in a VPSA setup. While a binder is generally required to shape zeolites and zeotypes into the macroscopic format (<em>e.g.</em> beads, pellets) needed for application in a VPSA column, in this work binderless LTA and SAPO-34 beads were studied and compared with commercial binder-containing zeolite 4A beads. Binary breakthrough experiments were conducted with a gas mixture mimicking biogas (<em>i.e.</em> 40 vol% CO<small><sub>2</sub></small> and 60 vol% CH<small><sub>4</sub></small>) in a single adsorption column up to 4 bar. The SAPO-34 beads displayed a slightly steeper breakthrough with less significant tailing compared to the LTA beads, which was ascribed to faster intra-crystalline diffusion due to the different framework structure and the lower adsorption strength of CO<small><sub>2</sub></small> on SAPO-34 compared to LTA. Notably, both the binderless LTA and SAPO-34 beads displayed a slightly sharper breakthrough and less significant tailing compared to commercial 4A beads. This was attributed to the open and accessible hierarchical pore structure of the binderless beads. The CO<small><sub>2</sub></small> adsorption capacity for the SAPO-34 beads was relatively stable over 5 cycles, while the LTA and commercial 4A beads displayed a significant decrease in adsorption capacity from the first to the second cycle. For the SAPO-34 beads, a cyclic adsorption capacity at breakthrough around 2 mmol g<small><sup>−1</sup></small> and a CO<small><sub>2</sub></small> productivity > 3 mol kg<small><sup>−1</sup></small> h<small><sup>−1</sup></small> were achieved. These values are significantly higher than those of the LTA and commercial 4A beads, making the SAPO-34 beads a promising candidate for industrial application in VPSA.</p>","PeriodicalId":72913,"journal":{"name":"Energy advances","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2024-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/ya/d4ya00007b?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141196951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nicholas Hunwick, Xiaolei Liu, Mustafa Togay, John M. Walls, Jake Bowers and Patrick J. M. Isherwood
Thin film CdTe-based photovoltaic devices have achieved high efficiency above 22%. However, the device performance is limited by large open circuit voltage deficit. One of the primary reasons is non-ohmic back contacts. In this work, nickel oxide is used as a back buffer layer to form an ohmic back contact. We comprehensively investigate oxygen effects during sputtering on film properties and device performance. Increased oxygen in the deposition environment led to darker films, increased carrier concentration, decreased mobility and decreased resistivity. X-ray photoelectron spectroscopy showed peak shifts favouring Ni3+ over Ni2+, and X-ray diffraction demonstrated that crystallinity hit a peak at around 5% oxygen input. The NiO back buffer layer improves device performance by reducing barrier height at the gold back contact and improving valence band offset at the CdTe/NiO interface. The NiO layer deposited without oxygen improved the Voc to 710 mV, from a baseline of 585 mV. At 5% and 20% oxygen content during deposition, efficiency improved relative to the reference due to an increase in open circuit voltage (Voc) and short circuit current (Jsc). Voc increase is due to improved valence band offset between CdTe and NiO. The large conduction band offset also reflects minority carriers away from the CdTe/NiO interface and reduces interface recombination. SCAPS simulations demonstrated that an increase in valence band offset has shown pronounced effects of both s-kinks and rollover.
基于碲化镉的薄膜光伏器件已经实现了 22% 以上的高效率。然而,该器件的性能受到开路电压缺口较大的限制。其中一个主要原因是非欧姆背触点。在这项研究中,氧化镍被用作背面缓冲层,以形成欧姆背接触。我们全面研究了溅射过程中氧对薄膜特性和器件性能的影响。沉积环境中氧的增加导致薄膜颜色变深、载流子浓度增加、迁移率降低和电阻率下降。X 射线光电子能谱显示,Ni3+ 的峰值偏向于 Ni2+,而 X 射线衍射则表明,在氧气输入量为 5%左右时,结晶度达到峰值。氧化镍背缓冲层可降低金背接触处的势垒高度,改善碲化镉/氧化镍界面的价带偏移,从而提高器件性能。无氧沉积的氧化镍层将 Voc 从 585mV 的基线提高到 710mV。在沉积过程中,氧含量分别为 5%和 20%时,由于开路电压(Voc)和短路电流(Jsc)的增加,效率相对于参考值有所提高。Voc 的增加是由于碲化镉和氧化镍之间价带偏移的改善。较大的导带偏移也将少数载流子从碲化镉/氧化镍界面反射出去,减少了界面重组。SCAPS 模拟表明,价带偏移的增加对 S 形扭结和翻转都有明显的影响。
{"title":"The effect of oxygen on NiO as a back buffer layer in CdTe solar cells","authors":"Nicholas Hunwick, Xiaolei Liu, Mustafa Togay, John M. Walls, Jake Bowers and Patrick J. M. Isherwood","doi":"10.1039/D4YA00125G","DOIUrl":"10.1039/D4YA00125G","url":null,"abstract":"<p >Thin film CdTe-based photovoltaic devices have achieved high efficiency above 22%. However, the device performance is limited by large open circuit voltage deficit. One of the primary reasons is non-ohmic back contacts. In this work, nickel oxide is used as a back buffer layer to form an ohmic back contact. We comprehensively investigate oxygen effects during sputtering on film properties and device performance. Increased oxygen in the deposition environment led to darker films, increased carrier concentration, decreased mobility and decreased resistivity. X-ray photoelectron spectroscopy showed peak shifts favouring Ni<small><sup>3+</sup></small> over Ni<small><sup>2+</sup></small>, and X-ray diffraction demonstrated that crystallinity hit a peak at around 5% oxygen input. The NiO back buffer layer improves device performance by reducing barrier height at the gold back contact and improving valence band offset at the CdTe/NiO interface. The NiO layer deposited without oxygen improved the <em>V</em><small><sub>oc</sub></small> to 710 mV, from a baseline of 585 mV. At 5% and 20% oxygen content during deposition, efficiency improved relative to the reference due to an increase in open circuit voltage (<em>V</em><small><sub>oc</sub></small>) and short circuit current (<em>J</em><small><sub>sc</sub></small>). <em>V</em><small><sub>oc</sub></small> increase is due to improved valence band offset between CdTe and NiO. The large conduction band offset also reflects minority carriers away from the CdTe/NiO interface and reduces interface recombination. SCAPS simulations demonstrated that an increase in valence band offset has shown pronounced effects of both s-kinks and rollover.</p>","PeriodicalId":72913,"journal":{"name":"Energy advances","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2024-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/ya/d4ya00125g?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141196946","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tomoki Takahashi, Di Wang, Jinkwang Hwang and Kazuhiko Matsumoto
Lithium metal batteries are a significant promise for next-generation energy storage due to their high energy density. However, challenges persist in their commercialization stemming from issues during the lithium deposition/dissolution processes, such as low Coulombic efficiency, dendrite formation, and dead-lithium formation. Addressing these challenges requires careful electrolyte design to enhance the reversibility of the lithium metal negative electrode by modifying solvation structures and engineering interfaces. The Coulombic efficiency of lithium deposition/dissolution is one of the most crucial factors in evaluating the performance of electrolytes toward lithium metal, although this is influenced by various factors. In this study, a separator-free cell is adopted to minimize extraneous influences and focus on assessing the intrinsic effects of electrolytes on lithium deposition/dissolution. 48 different electrolytes based on three salts of Li[PF6], Li[FSA] and Li[TFSA] varying in solvents were investigated with or without additives. Moreover, Raman spectroscopy and X-ray photon spectroscopy enhance the discussion by revealing variations in the major species of solid electrolyte interphase components under different electrolyte conditions.
锂金属电池因其高能量密度而成为下一代能源存储的重要保证。然而,由于锂沉积/溶解过程中的问题,如库仑效率低、枝晶形成和死锂形成等,其商业化仍面临挑战。要应对这些挑战,需要精心设计电解质,通过改变溶解结构和工程界面来提高锂金属负极的可逆性。锂沉积/溶解的库仑效率是评估电解液对锂金属性能的最关键因素之一,但这受到各种因素的影响。本研究采用无隔膜电池,以尽量减少外在影响,并重点评估电解质对锂沉积/溶解的内在影响。研究了基于锂[PF6]、锂[FSA]和锂[TFSA]三种盐的 48 种不同电解质,这些电解质在溶剂中各不相同,有的含有添加剂,有的没有添加剂。此外,拉曼光谱和 X 射线光子光谱揭示了不同电解质条件下固体电解质相间成分主要种类的变化,从而加强了讨论。
{"title":"Intrinsic effects of electrolytes on lithium metal deposition and dissolution investigated through a separator-free cell†","authors":"Tomoki Takahashi, Di Wang, Jinkwang Hwang and Kazuhiko Matsumoto","doi":"10.1039/D4YA00245H","DOIUrl":"10.1039/D4YA00245H","url":null,"abstract":"<p >Lithium metal batteries are a significant promise for next-generation energy storage due to their high energy density. However, challenges persist in their commercialization stemming from issues during the lithium deposition/dissolution processes, such as low Coulombic efficiency, dendrite formation, and dead-lithium formation. Addressing these challenges requires careful electrolyte design to enhance the reversibility of the lithium metal negative electrode by modifying solvation structures and engineering interfaces. The Coulombic efficiency of lithium deposition/dissolution is one of the most crucial factors in evaluating the performance of electrolytes toward lithium metal, although this is influenced by various factors. In this study, a separator-free cell is adopted to minimize extraneous influences and focus on assessing the intrinsic effects of electrolytes on lithium deposition/dissolution. 48 different electrolytes based on three salts of Li[PF<small><sub>6</sub></small>], Li[FSA] and Li[TFSA] varying in solvents were investigated with or without additives. Moreover, Raman spectroscopy and X-ray photon spectroscopy enhance the discussion by revealing variations in the major species of solid electrolyte interphase components under different electrolyte conditions.</p>","PeriodicalId":72913,"journal":{"name":"Energy advances","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/ya/d4ya00245h?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141168686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Christos K. Mytafides, William J. Wright, Raden Gustinvil, Lazaros Tzounis, George Karalis, Alkiviadis S. Paipetis and Emrah Celik
Moving the fabrication of electronics from the conventional 2D orientation to 3D space, necessitates the use of sophisticated additive manufacturing processes which are capable to deliver multifunctional materials and devices with exceptional spatial resolution. In this study, it is reported the nozzle-guided 3D-printing of highly conductive, epoxy-dispersed, single-walled carbon nanotube (SWCNT) architectures with embedded thermoelectric (TE) properties, capable to exploit significant waste thermal energy from the environment. In order to achieve high-resolution and continuous printing with the SWCNT-based paste through a confined nozzle geometry, i.e. without agglomeration and nozzle clogging, a homogeneous epoxy resin-dispersed SWCNT paste was produced. As a result, various 3D-printed structures with high SWCNT concentration (10 wt%) were obtained via shear-mixing processes. The 3D printed p- and n-type epoxy-dispersed SWCNT-based thermoelements exhibit high power factors of 102 and 75 μW mK−2, respectively. The manufactured 3D carbon-based thermoelectric generator (3D-CTEG) has the ability to stably operate at temperatures up to 180 °C in ambient conditions (1 atm, relative humidity: 50 ± 5% RH), obtaining TE values of an open-circuit voltage VOC = 13.6 mV, short-circuit current ISC = 1204 μA, internal resistance RTEG = 11.3 Ohm, and a generated power output Pmax = 4.1 μW at ΔT = 100 K (with TCold = 70 °C). The approach and methodology described in this study aims to increase the flexibility of integration and additive manufacturing processes for advanced 3D-printed conceptual devices and the development of multifunctional materials.
要将电子器件的制造从传统的二维方向转移到三维空间,就必须使用复杂的增材制造工艺,这种工艺能够提供具有特殊空间分辨率的多功能材料和器件。本研究报告了喷嘴引导的高导电性、环氧树脂分散的石墨烯纳米管(GNT)结构的三维打印,这种结构具有嵌入式热电(TE)特性,能够利用环境中的大量废弃热能。为了通过限定的喷嘴几何形状实现基于石墨烯纳米管的浆料的高分辨率和连续打印,即不产生团聚和喷嘴堵塞,生产出了均匀的环氧树脂分散石墨烯纳米管浆料。因此,通过剪切混合工艺获得了各种具有高 GNT 浓度(10 wt %)的 3D 打印结构。三维打印的 p 型和 n 型环氧树脂分散 GNT 热电元件的功率因数分别高达 102 和 75 μW/mK2。制造出的三维碳基热电发生器(3D-CTEG)能够在温度高达 180 °C的环境条件(1 atm,相对湿度:50 ± 5% RH)下稳定工作,在 ΔΤ = 100 K(TCold=70°C)下获得开路电压 VOC = 13.6 mV、短路电流 ISC = 1204 μA、内阻 RTEG = 11.3 Ohm 和发电功率输出 PMAX = 4.1 μW 的 TE 值。本研究中描述的方法和方法论旨在提高先进 3D 打印概念设备的集成和增材制造工艺的灵活性,并开发多功能材料。
{"title":"Additive manufacturing of highly conductive carbon nanotube architectures towards carbon-based flexible thermoelectric generators","authors":"Christos K. Mytafides, William J. Wright, Raden Gustinvil, Lazaros Tzounis, George Karalis, Alkiviadis S. Paipetis and Emrah Celik","doi":"10.1039/D4YA00182F","DOIUrl":"10.1039/D4YA00182F","url":null,"abstract":"<p >Moving the fabrication of electronics from the conventional 2D orientation to 3D space, necessitates the use of sophisticated additive manufacturing processes which are capable to deliver multifunctional materials and devices with exceptional spatial resolution. In this study, it is reported the nozzle-guided 3D-printing of highly conductive, epoxy-dispersed, single-walled carbon nanotube (SWCNT) architectures with embedded thermoelectric (TE) properties, capable to exploit significant waste thermal energy from the environment. In order to achieve high-resolution and continuous printing with the SWCNT-based paste through a confined nozzle geometry, <em>i.e.</em> without agglomeration and nozzle clogging, a homogeneous epoxy resin-dispersed SWCNT paste was produced. As a result, various 3D-printed structures with high SWCNT concentration (10 wt%) were obtained <em>via</em> shear-mixing processes. The 3D printed p- and n-type epoxy-dispersed SWCNT-based thermoelements exhibit high power factors of 102 and 75 μW mK<small><sup>−2</sup></small>, respectively. The manufactured 3D carbon-based thermoelectric generator (3D-CTEG) has the ability to stably operate at temperatures up to 180 °C in ambient conditions (1 atm, relative humidity: 50 ± 5% RH), obtaining TE values of an open-circuit voltage <em>V</em><small><sub>OC</sub></small> = 13.6 mV, short-circuit current <em>I</em><small><sub>SC</sub></small> = 1204 μA, internal resistance <em>R</em><small><sub>TEG</sub></small> = 11.3 Ohm, and a generated power output <em>P</em><small><sub>max</sub></small> = 4.1 μW at Δ<em>T</em> = 100 K (with <em>T</em><small><sub>Cold</sub></small> = 70 °C). The approach and methodology described in this study aims to increase the flexibility of integration and additive manufacturing processes for advanced 3D-printed conceptual devices and the development of multifunctional materials.</p>","PeriodicalId":72913,"journal":{"name":"Energy advances","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/ya/d4ya00182f?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141173408","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ifeanyi Michael Smarte Anekwe, Bilainu Oboirien and Yusuf Makarfi Isa
This study investigated the performance of metal-doped HZSM-5 catalysts in the conversion of low alcohols to hydrocarbons (LATH). Catalysts, including unmodified HZSM-5 and metal-modified (Ni, Fe, and Co) HZSM-5, were evaluated at 350 and 400 °C with space velocities of 7 and 12 h−1 for LATH conversion. Characterisation techniques such as XRD, FTIR, SEM-EDS, PSD, N2 adsorption, and TGA-DTA were employed. The characterisation results showed the successful metal incorporation in the HZSM-5 support catalyst. The overall evaluation of catalyst performance for LATH conversion revealed that the metal-doped catalysts showed a clear preference for liquid hydrocarbons with >99% average low alcohol conversion compared to the unmodified catalysts. In particular, Co/HZSM-5 and Fe/HZSM-5 showed a considerable preference for C5–C8 (62.81% and 54.95%), while Ni/HZSM-5 improved the synthesis of C9–C12 (11.40%), C12+ (20.91%) and BTX (7.01%). The study on coke deposition indicated that Ni/HZSM-5 exhibited stability with minimal coke formation, while Co/HZSM-5 experienced higher coke deposition and deactivation tendencies in MTH and ETH conversions, respectively. Co/HZSM-5 exhibited the lowest weight loss, whereas Fe/HZSM-5 showed lower stability in PTH conversion. Notably, Ni/HZSM-5 demonstrated remarkable stability and performance in LATH conversion. These findings contribute to the advancement of catalysis and the transition towards a sustainable energy future.
{"title":"Performance evaluation of a newly developed transition metal-doped HZSM-5 zeolite catalyst for single-step conversion of C1–C3 alcohols to fuel-range hydrocarbons†","authors":"Ifeanyi Michael Smarte Anekwe, Bilainu Oboirien and Yusuf Makarfi Isa","doi":"10.1039/D3YA00460K","DOIUrl":"10.1039/D3YA00460K","url":null,"abstract":"<p >This study investigated the performance of metal-doped HZSM-5 catalysts in the conversion of low alcohols to hydrocarbons (LATH). Catalysts, including unmodified HZSM-5 and metal-modified (Ni, Fe, and Co) HZSM-5, were evaluated at 350 and 400 °C with space velocities of 7 and 12 h<small><sup>−1</sup></small> for LATH conversion. Characterisation techniques such as XRD, FTIR, SEM-EDS, PSD, N<small><sub>2</sub></small> adsorption, and TGA-DTA were employed. The characterisation results showed the successful metal incorporation in the HZSM-5 support catalyst. The overall evaluation of catalyst performance for LATH conversion revealed that the metal-doped catalysts showed a clear preference for liquid hydrocarbons with >99% average low alcohol conversion compared to the unmodified catalysts. In particular, Co/HZSM-5 and Fe/HZSM-5 showed a considerable preference for C<small><sub>5</sub></small>–C<small><sub>8</sub></small> (62.81% and 54.95%), while Ni/HZSM-5 improved the synthesis of C<small><sub>9</sub></small>–C<small><sub>12</sub></small> (11.40%), C<small><sub>12</sub></small><small><sup>+</sup></small> (20.91%) and BTX (7.01%). The study on coke deposition indicated that Ni/HZSM-5 exhibited stability with minimal coke formation, while Co/HZSM-5 experienced higher coke deposition and deactivation tendencies in MTH and ETH conversions, respectively. Co/HZSM-5 exhibited the lowest weight loss, whereas Fe/HZSM-5 showed lower stability in PTH conversion. Notably, Ni/HZSM-5 demonstrated remarkable stability and performance in LATH conversion. These findings contribute to the advancement of catalysis and the transition towards a sustainable energy future.</p>","PeriodicalId":72913,"journal":{"name":"Energy advances","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/ya/d3ya00460k?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141168790","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}