Pub Date : 2024-08-14DOI: 10.1016/j.mtener.2024.101669
Xian-Lan Chen, Bao-Feng Shan, Zong-Yan Zhao
This study delves into the effects of 3d transition metal (TM) spin states on the structural and electronic properties of CuAlTMO solid solutions, focusing on their implications for photo(electro)catalytic performance. The research reveals that the Jahn–Teller distortion, associated with TM, is a critical factor in determining the lattice parameters and photo(electro)catalytic performances. Solid solutions without Jahn–Teller distortion adhere to Vegard's law, whereas those with strong distortion exhibit deviations, indicating the influence of TMO octahedral distortion on solubility and lattice parameters. The electronic structure of solid solutions with weak Jahn–Teller distortion is governed by the O–Cu–O and TMO crystal fields, which leads to a narrowed bandgap and reduced conduction band minimum (CBM), impacting the hydrogen evolution potential. In particular, the CuAlCrO shows a significant enhancement in photocurrent density and hydrogen production rate due to its balanced light absorption and effective charge carrier separation. In contrast, the weak Jahn–Teller distortion in CuAlFeO results in localized electronic states at CBM, leading to diminished carrier mobility. Solid solutions with strong Jahn–Teller distortion, such as CuAlTMO (TM = Mn and Ni), display a range of electronic properties from semiconductor to semimetallic, with the semimetallic CuAlMnO capable of infrared light absorption and efficient photocatalytic hydrogen and oxygen production.
{"title":"Designing delafossite CuAl1-xTMxO2 solid solutions: the role of 3d transition metal spin states in photo(electro)catalytic performance","authors":"Xian-Lan Chen, Bao-Feng Shan, Zong-Yan Zhao","doi":"10.1016/j.mtener.2024.101669","DOIUrl":"https://doi.org/10.1016/j.mtener.2024.101669","url":null,"abstract":"This study delves into the effects of 3d transition metal (TM) spin states on the structural and electronic properties of CuAlTMO solid solutions, focusing on their implications for photo(electro)catalytic performance. The research reveals that the Jahn–Teller distortion, associated with TM, is a critical factor in determining the lattice parameters and photo(electro)catalytic performances. Solid solutions without Jahn–Teller distortion adhere to Vegard's law, whereas those with strong distortion exhibit deviations, indicating the influence of TMO octahedral distortion on solubility and lattice parameters. The electronic structure of solid solutions with weak Jahn–Teller distortion is governed by the O–Cu–O and TMO crystal fields, which leads to a narrowed bandgap and reduced conduction band minimum (CBM), impacting the hydrogen evolution potential. In particular, the CuAlCrO shows a significant enhancement in photocurrent density and hydrogen production rate due to its balanced light absorption and effective charge carrier separation. In contrast, the weak Jahn–Teller distortion in CuAlFeO results in localized electronic states at CBM, leading to diminished carrier mobility. Solid solutions with strong Jahn–Teller distortion, such as CuAlTMO (TM = Mn and Ni), display a range of electronic properties from semiconductor to semimetallic, with the semimetallic CuAlMnO capable of infrared light absorption and efficient photocatalytic hydrogen and oxygen production.","PeriodicalId":18277,"journal":{"name":"Materials Today Energy","volume":"23 1","pages":""},"PeriodicalIF":9.3,"publicationDate":"2024-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142188322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-08-14DOI: 10.1016/j.mtener.2024.101671
Doudou Zhao, Da Xu, Tiantian Wang, Zhenglong Yang
The zinc-ion hybrid capacitor, as a novel energy storage system with outstanding electrochemical performance, low cost, and high safety, has attracted widespread research attention. In this work, we report a hetero-structured composite material, CN@MXene, obtained by alternately stacking porous carbon material CN with MXene nanosheets. Theoretical calculations and a series of characterizations reveal that the introduction of MXene nanosheets not only exposes more active sites of CN, but also significantly enhances the conductivity and stability of the overall composite material, thereby achieving excellent electrochemical energy storage performance. Consequently, as a cathode material for zinc-ion hybrid capacitors, CN @MXene achieves a high specific capacity of 240 mA h/g at 0.1 A/g and exhibits outstanding rate performance from 1 to 20 A/g. And the capacitance retention rate remains as high as 94%, after 10,000 cycles of charge-discharge at a current density of 5 A/g. Moreover, based on the CN @MXene electrode, flexible zinc ion micro-capacitor with high area-specific capacity of 264 mF/cm was fabricated using laser cutting technology. We believe that this work provides new research strategies for developing high-performance zinc-ion hybrid capacitors.
{"title":"Nitrogen-rich nanoporous carbon with MXene composite for high-performance Zn-ion hybrid capacitors","authors":"Doudou Zhao, Da Xu, Tiantian Wang, Zhenglong Yang","doi":"10.1016/j.mtener.2024.101671","DOIUrl":"https://doi.org/10.1016/j.mtener.2024.101671","url":null,"abstract":"The zinc-ion hybrid capacitor, as a novel energy storage system with outstanding electrochemical performance, low cost, and high safety, has attracted widespread research attention. In this work, we report a hetero-structured composite material, CN@MXene, obtained by alternately stacking porous carbon material CN with MXene nanosheets. Theoretical calculations and a series of characterizations reveal that the introduction of MXene nanosheets not only exposes more active sites of CN, but also significantly enhances the conductivity and stability of the overall composite material, thereby achieving excellent electrochemical energy storage performance. Consequently, as a cathode material for zinc-ion hybrid capacitors, CN @MXene achieves a high specific capacity of 240 mA h/g at 0.1 A/g and exhibits outstanding rate performance from 1 to 20 A/g. And the capacitance retention rate remains as high as 94%, after 10,000 cycles of charge-discharge at a current density of 5 A/g. Moreover, based on the CN @MXene electrode, flexible zinc ion micro-capacitor with high area-specific capacity of 264 mF/cm was fabricated using laser cutting technology. We believe that this work provides new research strategies for developing high-performance zinc-ion hybrid capacitors.","PeriodicalId":18277,"journal":{"name":"Materials Today Energy","volume":"28 1","pages":""},"PeriodicalIF":9.3,"publicationDate":"2024-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142188323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Despite the extensive advancements in recent years, polymeric daytime radiative cooling (PDRC) coatings face certain challenges, encompassing restricted spectral performance, susceptibility to aging, poor mechanical strength, and so forth. Herein, we proposed a facile biomimetic 500 μm thick PDRC coating, featuring a gradient distribution of pore sizes throughout the cross-section. The proposed functional structure demonstrates spectral characteristics of a near-ideal broadband emitter by attaining over 0.95 emissivity in the main atmospheric window and 0.99 reflectance in the visible spectrum. During the outdoor experiment, it achieved an 8.5 °C subambient temperature drop along with a cooling power of ∼106 W/m at the solar irradiance of ∼800 W/m and ∼650 W/m, respectively. Experimental findings highlight that the bioinspired design results in a tensile strength of ∼9 MPa along with a tensile strain of over 200%, which is more than twice that of non-gradient porous PDRC coatings. In addition, it offers tunable surface contact angle and manifests its resilience in anti-ultraviolet and water resistance tests. Furthermore, a building energy model reveals a decrease in cooling load of between 34 and 119 kWh/(m.year), establishing its real-world application under broader climatic regions.
{"title":"A bioinspired hierarchical gradient structure to maximize resilience and enhanced cooling performance in polymeric radiative cooling coatings","authors":"Abdul Samad Farooq, Xihao Song, Duihong Wei, Leyang Liu, Peng Zhang","doi":"10.1016/j.mtener.2024.101666","DOIUrl":"https://doi.org/10.1016/j.mtener.2024.101666","url":null,"abstract":"Despite the extensive advancements in recent years, polymeric daytime radiative cooling (PDRC) coatings face certain challenges, encompassing restricted spectral performance, susceptibility to aging, poor mechanical strength, and so forth. Herein, we proposed a facile biomimetic 500 μm thick PDRC coating, featuring a gradient distribution of pore sizes throughout the cross-section. The proposed functional structure demonstrates spectral characteristics of a near-ideal broadband emitter by attaining over 0.95 emissivity in the main atmospheric window and 0.99 reflectance in the visible spectrum. During the outdoor experiment, it achieved an 8.5 °C subambient temperature drop along with a cooling power of ∼106 W/m at the solar irradiance of ∼800 W/m and ∼650 W/m, respectively. Experimental findings highlight that the bioinspired design results in a tensile strength of ∼9 MPa along with a tensile strain of over 200%, which is more than twice that of non-gradient porous PDRC coatings. In addition, it offers tunable surface contact angle and manifests its resilience in anti-ultraviolet and water resistance tests. Furthermore, a building energy model reveals a decrease in cooling load of between 34 and 119 kWh/(m.year), establishing its real-world application under broader climatic regions.","PeriodicalId":18277,"journal":{"name":"Materials Today Energy","volume":"9 1","pages":""},"PeriodicalIF":9.3,"publicationDate":"2024-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142259791","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-08-14DOI: 10.1016/j.mtener.2024.101672
Jaeseon Lee, Jinsoo Yoon, Seong-Geun Oh
The core-shell nanofibers containing PDA-PEI co-modified LiLaTiO (LLTO) perovskite nanowires in the shell layer were fabricated by co-axial electrospinning technique to apply as separator in dendrite-free lithium metal batteries. The PVDF-HFP with good mechanical properties and polar C–F bonds was used as the core material, and polyacrylonitrile (PAN) with high thermal stability was employed as the shell layer in nanofibers. The PDA-PEI co-modified LiLaTiO nanowires, reacting with PF anions in LiPF salt can not only capture free anions but also provide a lithium-ion migration pathway. Moreover, the core-shell structured nanofibers exhibited high mechanical strength (9.2 N/mm), robust thermal stability (>0% at 200 °C for 1 h), and favorable electrolyte affinity (electrolyte uptake of 732%). Gelation of PVDF-HFP in liquid electrolyte leads to high-ionic conductivity (3.52 mS/cm), Li transference number (t = 0.68), uniform Li flux, and smooth Li deposition. The Li plating/stripping test consisting of Li–Li cells (with CS/LLTO-PDA-PEI) carried out at 0.4 mA/cm was conducted for 1000 h without a short circuit. NCM-Li and NCM-Gr coin cells using the CS (core-shell)/LLTO-PDA-PEI separator retained long-term cycle stability and good Coulombic efficiency (CE).
{"title":"Core-shell nanofiber separator incorporated with PDA-PEI co-modified Li0.33La0.57TiO3 nanowires prepared by co-axial electrospinning for dendrite-free lithium metal batteries","authors":"Jaeseon Lee, Jinsoo Yoon, Seong-Geun Oh","doi":"10.1016/j.mtener.2024.101672","DOIUrl":"https://doi.org/10.1016/j.mtener.2024.101672","url":null,"abstract":"The core-shell nanofibers containing PDA-PEI co-modified LiLaTiO (LLTO) perovskite nanowires in the shell layer were fabricated by co-axial electrospinning technique to apply as separator in dendrite-free lithium metal batteries. The PVDF-HFP with good mechanical properties and polar C–F bonds was used as the core material, and polyacrylonitrile (PAN) with high thermal stability was employed as the shell layer in nanofibers. The PDA-PEI co-modified LiLaTiO nanowires, reacting with PF anions in LiPF salt can not only capture free anions but also provide a lithium-ion migration pathway. Moreover, the core-shell structured nanofibers exhibited high mechanical strength (9.2 N/mm), robust thermal stability (>0% at 200 °C for 1 h), and favorable electrolyte affinity (electrolyte uptake of 732%). Gelation of PVDF-HFP in liquid electrolyte leads to high-ionic conductivity (3.52 mS/cm), Li transference number (t = 0.68), uniform Li flux, and smooth Li deposition. The Li plating/stripping test consisting of Li–Li cells (with CS/LLTO-PDA-PEI) carried out at 0.4 mA/cm was conducted for 1000 h without a short circuit. NCM-Li and NCM-Gr coin cells using the CS (core-shell)/LLTO-PDA-PEI separator retained long-term cycle stability and good Coulombic efficiency (CE).","PeriodicalId":18277,"journal":{"name":"Materials Today Energy","volume":"6 1","pages":""},"PeriodicalIF":9.3,"publicationDate":"2024-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142188436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-08-13DOI: 10.1016/j.mtener.2024.101665
Yulei Ma, Jing Wei, Liujie Xu, Yuanfa Zhuang, Ya Huang, Lin Yang, Lu Yao, Wenju Jiang, Zhongde Dai
Mixed matrix membranes (MMMs) are more likely to break the Robeson upper bound because they combine the pros of both organic and inorganic membranes. However, in the conventional MMM preparation processes, multi-steps are normally needed and, in many cases, the particle agglomeration and consequent non-selective voids are unavoidable, resulting in poor carbon dioxide (CO) separation performances. In addition, the agglomeration makes it challenging to fabricate thin-film nanocomposite (TFN) membranes. In this study, zeolitic imidazolate framework (ZIF)-8- and ZIF-67-based TFN membranes were fabricated via a facile one-pot in situ synthesis protocol. The ZIF particles were synthesized in the polymeric solution, then the TFN membranes were fabricated by a dip coating method. With a casting solution concentration of 1.5 %, a selective layer with a thickness of ∼300 nm can be prepared on the porous polyacrylonitrile (PAN) support. The results of thermogravimetric analysis (TGA), differential scanning calorimeter (DSC), Fourier Transform Infrared (FT-IR) spectroscopy, and X-ray diffraction (XRD) showed that ZIFs were successfully synthesized in the casting solution. At 35 °C and 2 bar, the membrane containing 5 % ZIF-67 had a CO permeance of 223.35 gas permeation unit (GPU), which was 16.55 % higher than that of pure Pebax.
混合基质膜（MMM）更有可能打破罗伯逊上限，因为它们结合了有机膜和无机膜的优点。然而，在传统的混合基质膜制备过程中，通常需要多个步骤，而且在许多情况下，颗粒团聚和随之而来的非选择性空隙是不可避免的，从而导致二氧化碳（CO）分离性能不佳。此外，团聚使薄膜纳米复合（TFN）膜的制造面临挑战。在本研究中，通过简单的一锅原位合成方案，制备了基于沸石咪唑酸框架（ZIF）-8 和 ZIF-67 的 TFN 膜。先在聚合物溶液中合成 ZIF 颗粒，然后采用浸涂法制备 TFN 膜。浇铸溶液浓度为 1.5 % 时，可在多孔聚丙烯腈（PAN）支架上制备出厚度为 300 nm 的选择性层。热重分析（TGA）、差示扫描量热仪（DSC）、傅立叶变换红外光谱（FT-IR）和 X 射线衍射（XRD）的结果表明，在浇铸溶液中成功合成了 ZIF。在 35 °C 和 2 bar 条件下，含 5% ZIF-67 的膜的 CO 渗透率为 223.35 气体渗透单位 (GPU)，比纯 Pebax 高 16.55%。
{"title":"One-pot in situ synthesis of ZIF particles to prepare thin-film nanocomposite membranes for CO2 separation","authors":"Yulei Ma, Jing Wei, Liujie Xu, Yuanfa Zhuang, Ya Huang, Lin Yang, Lu Yao, Wenju Jiang, Zhongde Dai","doi":"10.1016/j.mtener.2024.101665","DOIUrl":"https://doi.org/10.1016/j.mtener.2024.101665","url":null,"abstract":"Mixed matrix membranes (MMMs) are more likely to break the Robeson upper bound because they combine the pros of both organic and inorganic membranes. However, in the conventional MMM preparation processes, multi-steps are normally needed and, in many cases, the particle agglomeration and consequent non-selective voids are unavoidable, resulting in poor carbon dioxide (CO) separation performances. In addition, the agglomeration makes it challenging to fabricate thin-film nanocomposite (TFN) membranes. In this study, zeolitic imidazolate framework (ZIF)-8- and ZIF-67-based TFN membranes were fabricated via a facile one-pot in situ synthesis protocol. The ZIF particles were synthesized in the polymeric solution, then the TFN membranes were fabricated by a dip coating method. With a casting solution concentration of 1.5 %, a selective layer with a thickness of ∼300 nm can be prepared on the porous polyacrylonitrile (PAN) support. The results of thermogravimetric analysis (TGA), differential scanning calorimeter (DSC), Fourier Transform Infrared (FT-IR) spectroscopy, and X-ray diffraction (XRD) showed that ZIFs were successfully synthesized in the casting solution. At 35 °C and 2 bar, the membrane containing 5 % ZIF-67 had a CO permeance of 223.35 gas permeation unit (GPU), which was 16.55 % higher than that of pure Pebax.","PeriodicalId":18277,"journal":{"name":"Materials Today Energy","volume":"38 1","pages":""},"PeriodicalIF":9.3,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142188324","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-08-10DOI: 10.1016/j.mtener.2024.101664
Jingmiao Jia, Bin Guo, Huawei Gao, Yanwei Zhao, Guojie Li, Aoxuan Wang, Chuntai Liu
With the development of the next-generation energy storage systems, rechargeable secondary batteries that improve energy density and safety are necessary to achieve energy iteration. Because of their low cost and high energy density, sodium metal batteries (SMBs) have great potential in the future. However, due to the instability of the solid electrolyte interface (SEI), the growth of sodium dendrites, and the volume expansion of the sodium metal anodes (SMAs) during planting and stripping, its practical implementation is hindered. In recent years, with the deepening of polymer chemistry research, polymers have been widely used to improve the batteries’ actual performance, safety, and durability as a result of their strong chemical stability, processability, structural designability, and functional diversity. Based on the basic understanding of the relationship between polymer structure and properties, polymer design and common processing methods of stable SMAs are systematically summarized. Furthermore, the strategies of polymers to stabilize SMAs were reviewed from five aspects: artificial SEI, separators, gel polymer electrolytes, solid polymer electrolytes, and anode hosts. The current research status and difficulties in optimizing SMAs to achieve high stability are discussed. Finally, the challenges and potential development directions of SMAs are discussed.
随着下一代储能系统的发展，提高能量密度和安全性的可充电二次电池是实现能量迭代的必要条件。钠金属电池（SMB）因其低成本和高能量密度，在未来具有巨大的发展潜力。然而，由于固体电解质界面（SEI）的不稳定性、钠树枝状物的生长以及钠金属阳极（SMA）在种植和剥离过程中的体积膨胀，其实际应用受到了阻碍。近年来，随着高分子化学研究的不断深入，聚合物因其化学稳定性强、可加工性好、结构可设计性强、功能多样化等特点，被广泛应用于提高电池的实际性能、安全性和耐久性。基于对聚合物结构与性能关系的基本认识，系统总结了稳定 SMA 的聚合物设计和常用加工方法。此外，还从人工 SEI、分离器、凝胶聚合物电解质、固体聚合物电解质和阳极宿主五个方面综述了聚合物稳定 SMA 的策略。讨论了优化 SMA 以实现高稳定性的研究现状和难点。最后，讨论了 SMAs 所面临的挑战和潜在的发展方向。
{"title":"Stabilizing sodium metal anodes by functional polymers","authors":"Jingmiao Jia, Bin Guo, Huawei Gao, Yanwei Zhao, Guojie Li, Aoxuan Wang, Chuntai Liu","doi":"10.1016/j.mtener.2024.101664","DOIUrl":"https://doi.org/10.1016/j.mtener.2024.101664","url":null,"abstract":"With the development of the next-generation energy storage systems, rechargeable secondary batteries that improve energy density and safety are necessary to achieve energy iteration. Because of their low cost and high energy density, sodium metal batteries (SMBs) have great potential in the future. However, due to the instability of the solid electrolyte interface (SEI), the growth of sodium dendrites, and the volume expansion of the sodium metal anodes (SMAs) during planting and stripping, its practical implementation is hindered. In recent years, with the deepening of polymer chemistry research, polymers have been widely used to improve the batteries’ actual performance, safety, and durability as a result of their strong chemical stability, processability, structural designability, and functional diversity. Based on the basic understanding of the relationship between polymer structure and properties, polymer design and common processing methods of stable SMAs are systematically summarized. Furthermore, the strategies of polymers to stabilize SMAs were reviewed from five aspects: artificial SEI, separators, gel polymer electrolytes, solid polymer electrolytes, and anode hosts. The current research status and difficulties in optimizing SMAs to achieve high stability are discussed. Finally, the challenges and potential development directions of SMAs are discussed.","PeriodicalId":18277,"journal":{"name":"Materials Today Energy","volume":"13 1","pages":""},"PeriodicalIF":9.3,"publicationDate":"2024-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142188474","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-08-09DOI: 10.1016/j.mtener.2024.101658
Angel Burgos, Junteng Du, Danna Yan, Yazhou Zhou, Hannah Levy, Jeong Gi Ryu, Jae Chul Kim
Lithium phospho-olivine cathodes operating with iron (Fe) and manganese (Mn) redox centers are considered technologically important materials that can make the development of Li-ion batteries sustainable. Although large Mn content is desirable to achieve high specific energy at a material level, the mixed olivine cathodes require particle nanostructuring and post-synthesis treatment to demonstrate reasonable energy storage properties at an electrode level. In this work, we have investigated the effect of off-stoichiometry on the electrochemical properties of a Mn-rich mixed olivine cathode material that does not require complex optimization processing. An off-stoichiometric form of LiFeMnPO is synthesized with nominal composition of LiFeMnPO. X-ray diffraction and electron microscopy indicate that off-stoichiometry leads to phase separation into stoichiometric LiFeMnPO crystalline particles with non-crystalline surface phases. The off-stoichiometric cathode has an improved specific energy of 622 Wh/kg at C/5, outperforming the stoichiometric cathode. The off-stoichiometric cathode also exhibits improved rate capability, delivering 120 mAh/g at 20C and 78 mAh/g at 40C discharge, respectively, due to reduced interfacial and charge transfer resistances. This work highlights off-stoichiometry as an effective approach to engineer Mn-rich mixed olivine cathode materials with desirable electrochemical properties, providing a practically feasible route for materials optimization.
{"title":"Off-stoichiometric design of a manganese-rich mixed olivine Li-ion cathode for improved specific energy","authors":"Angel Burgos, Junteng Du, Danna Yan, Yazhou Zhou, Hannah Levy, Jeong Gi Ryu, Jae Chul Kim","doi":"10.1016/j.mtener.2024.101658","DOIUrl":"https://doi.org/10.1016/j.mtener.2024.101658","url":null,"abstract":"Lithium phospho-olivine cathodes operating with iron (Fe) and manganese (Mn) redox centers are considered technologically important materials that can make the development of Li-ion batteries sustainable. Although large Mn content is desirable to achieve high specific energy at a material level, the mixed olivine cathodes require particle nanostructuring and post-synthesis treatment to demonstrate reasonable energy storage properties at an electrode level. In this work, we have investigated the effect of off-stoichiometry on the electrochemical properties of a Mn-rich mixed olivine cathode material that does not require complex optimization processing. An off-stoichiometric form of LiFeMnPO is synthesized with nominal composition of LiFeMnPO. X-ray diffraction and electron microscopy indicate that off-stoichiometry leads to phase separation into stoichiometric LiFeMnPO crystalline particles with non-crystalline surface phases. The off-stoichiometric cathode has an improved specific energy of 622 Wh/kg at C/5, outperforming the stoichiometric cathode. The off-stoichiometric cathode also exhibits improved rate capability, delivering 120 mAh/g at 20C and 78 mAh/g at 40C discharge, respectively, due to reduced interfacial and charge transfer resistances. This work highlights off-stoichiometry as an effective approach to engineer Mn-rich mixed olivine cathode materials with desirable electrochemical properties, providing a practically feasible route for materials optimization.","PeriodicalId":18277,"journal":{"name":"Materials Today Energy","volume":"13 1","pages":""},"PeriodicalIF":9.3,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142188325","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-08-08DOI: 10.1016/j.mtener.2024.101661
Henghui Chen, Jing Wang, Yuan Zhao, Xuefeng Zhou, Heran Yang, Yan Li, Yingmei Li, Ehsan Alborzi, Xue Yong, John S. Tse
Transition metal singlet embedded in nitrogen-doped carbon material (M-N-C) has been demonstrated as a promising electrochemical oxygen reduction reaction (ORR) catalyst; however, the unsatisfying activity and production selectivity have hampered its widespread applications in energy storage and conversion technologies. Herein, interface engineering by facilitating M-N-C catalysts (M from 3d to 4d electron-containing elements) with MXene has been utilized to regulate their ORR performance. It is found that the charge transfer occurring within the interface not only tunes the electron occupancy of the 3d/4d orbitals of the metal site, but also delocalizes the population of the d states. This alternation enhances the mobility of the electrons and promotes the 4e catalytic process thermodynamically. Meanwhile, the formation of ∗HOOH, the key reaction intermediate for 2e reaction, is hindered due to the alleviation of the binding capacity, which is beneficial to improve production selectivity. This study provides foundational understanding for the ORR catalytic mechanism at the atomic level and opens up new avenues for designing high-demanded electrocatalysts.
嵌入掺氮碳材料（M-N-C）中的过渡金属单质已被证明是一种前景广阔的电化学氧还原反应（ORR）催化剂；然而，由于活性和生产选择性不尽人意，阻碍了其在能源储存和转换技术中的广泛应用。在此，通过促进 M-N-C 催化剂（M 从 3d 到 4d 含电子元素）与 MXene 的界面工程来调节其 ORR 性能。研究发现，在界面内发生的电荷转移不仅调整了金属位点 3d/4d 轨道的电子占有率，而且还使 d 态的电子群失调。这种交替增强了电子的流动性，并在热力学上促进了 4e 催化过程。同时，由于结合能力的减弱，2e 反应的关键反应中间体 ∗HOOH 的形成受到阻碍，有利于提高生产选择性。这项研究为从原子水平理解 ORR 催化机理提供了基础，为设计高要求的电催化剂开辟了新的途径。
{"title":"Interface engineering of the dz2 electrons mobility for single atom catalytic activity and selectivity","authors":"Henghui Chen, Jing Wang, Yuan Zhao, Xuefeng Zhou, Heran Yang, Yan Li, Yingmei Li, Ehsan Alborzi, Xue Yong, John S. Tse","doi":"10.1016/j.mtener.2024.101661","DOIUrl":"https://doi.org/10.1016/j.mtener.2024.101661","url":null,"abstract":"Transition metal singlet embedded in nitrogen-doped carbon material (M-N-C) has been demonstrated as a promising electrochemical oxygen reduction reaction (ORR) catalyst; however, the unsatisfying activity and production selectivity have hampered its widespread applications in energy storage and conversion technologies. Herein, interface engineering by facilitating M-N-C catalysts (M from 3d to 4d electron-containing elements) with MXene has been utilized to regulate their ORR performance. It is found that the charge transfer occurring within the interface not only tunes the electron occupancy of the 3d/4d orbitals of the metal site, but also delocalizes the population of the d states. This alternation enhances the mobility of the electrons and promotes the 4e catalytic process thermodynamically. Meanwhile, the formation of ∗HOOH, the key reaction intermediate for 2e reaction, is hindered due to the alleviation of the binding capacity, which is beneficial to improve production selectivity. This study provides foundational understanding for the ORR catalytic mechanism at the atomic level and opens up new avenues for designing high-demanded electrocatalysts.","PeriodicalId":18277,"journal":{"name":"Materials Today Energy","volume":"101 1","pages":""},"PeriodicalIF":9.3,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142188327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-08-08DOI: 10.1016/j.mtener.2024.101663
Elizabeth A. Pogue, Spencer A. Langevin, Tanner Hamann, Karun K. Rao, Marshall A. Schroeder, Nam Q. Le, Courtney McHale, Zachary Burchfield, Jesse S. Ko
Low-temperature operation (−20 °C and below) under high-rate conditions is a critical deficiency for lithium-ion batteries. To achieve size, weight, and power requirements tailored for demanding applications, novel materials are needed to sustain high performance. In the present study, we synthesize a series of niobate anode materials (NbO, NbO, and NbO) and tailor their particle size, defect nature, and electrical/ionic conductivity to enable high-performance operation at −20 °C under high-rate conditions (1.2C–2C). When paired with lithium manganese oxide (LMO) in a full-cell configuration, the NbO-based full-cells achieve high-rate capability (∼90 mAh/g up to 2C cycling rate at −20 °C) and great long-term stability (>98% retention up to 50 cycles at −20 °C). During a simulated 30 min duty cycling test synthesized from measured data from an actual drone flight (continuous range of 1.2C–2C cycling rates), the NbO||LMO cell enables full discharge at −20 °C, with only a 0.3 V voltage drop when compared to duty cycling at room temperature. The work presented herein demonstrates the future possibilities of expanding the operational capabilities of lithium-ion batteries.
{"title":"Enhancing low-temperature lithium-ion battery performance under high-rate conditions with niobium oxides","authors":"Elizabeth A. Pogue, Spencer A. Langevin, Tanner Hamann, Karun K. Rao, Marshall A. Schroeder, Nam Q. Le, Courtney McHale, Zachary Burchfield, Jesse S. Ko","doi":"10.1016/j.mtener.2024.101663","DOIUrl":"https://doi.org/10.1016/j.mtener.2024.101663","url":null,"abstract":"Low-temperature operation (−20 °C and below) under high-rate conditions is a critical deficiency for lithium-ion batteries. To achieve size, weight, and power requirements tailored for demanding applications, novel materials are needed to sustain high performance. In the present study, we synthesize a series of niobate anode materials (NbO, NbO, and NbO) and tailor their particle size, defect nature, and electrical/ionic conductivity to enable high-performance operation at −20 °C under high-rate conditions (1.2C–2C). When paired with lithium manganese oxide (LMO) in a full-cell configuration, the NbO-based full-cells achieve high-rate capability (∼90 mAh/g up to 2C cycling rate at −20 °C) and great long-term stability (>98% retention up to 50 cycles at −20 °C). During a simulated 30 min duty cycling test synthesized from measured data from an actual drone flight (continuous range of 1.2C–2C cycling rates), the NbO||LMO cell enables full discharge at −20 °C, with only a 0.3 V voltage drop when compared to duty cycling at room temperature. The work presented herein demonstrates the future possibilities of expanding the operational capabilities of lithium-ion batteries.","PeriodicalId":18277,"journal":{"name":"Materials Today Energy","volume":"7 1","pages":""},"PeriodicalIF":9.3,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142188326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-08-08DOI: 10.1016/j.mtener.2024.101659
Xiaotong Liu, Zheng Han, Siying Zhao, Haoqing Tang, Tian Tian, Qiang Weng, Xiaohuan Liu, Tao Liu
Aqueous zinc-ion batteries (AZIBs) are considered to be one of the alternatives for large-scale energy storage devices due to unique advantages. However, the harmful Zn dendrites generation of Zn anodes seriously hinders the development of AZIBs. Herein, Cu(BTC) (HKUST-1) as a compact functional interface layer on the surface of bare Zn foil is shown to improve the reversibility of Zn-plating/stripping process. Interestingly, HKUST-1 possesses high porosity, large number of water molecule vacancies, and Cu active center, which help to enhance the diffusion kinetics of Zn and reduce the surface free energy of Zn electrode. Combining theoretical calculations with experiments, the HKUST-1 can contribute to the desolvation process of Zn[(HO)] and balance Zn concentration, which thus accelerate Zn transfer kinetics, lower interfacial energy, and homogenize ion-distribution. Attributed to these superiorities, the HKUST-1@Zn symmetric cells demonstrate excellent stable plating/stripping for over 250 h under ultra-high current density (20 mA/cm and 20 mAh/cm). Furthermore, a HKUST-1@Zn||MnO full cell exhibits an enhanced long-cycling performance with a discharge capacity of 114 mAh/g after undergoing 500 cycles. All results demonstrate the potential application of HKUST-1 coating in AZIBs.
{"title":"A HKUST-1 coating with copper metal active site enables stabilized zinc metal anode","authors":"Xiaotong Liu, Zheng Han, Siying Zhao, Haoqing Tang, Tian Tian, Qiang Weng, Xiaohuan Liu, Tao Liu","doi":"10.1016/j.mtener.2024.101659","DOIUrl":"https://doi.org/10.1016/j.mtener.2024.101659","url":null,"abstract":"Aqueous zinc-ion batteries (AZIBs) are considered to be one of the alternatives for large-scale energy storage devices due to unique advantages. However, the harmful Zn dendrites generation of Zn anodes seriously hinders the development of AZIBs. Herein, Cu(BTC) (HKUST-1) as a compact functional interface layer on the surface of bare Zn foil is shown to improve the reversibility of Zn-plating/stripping process. Interestingly, HKUST-1 possesses high porosity, large number of water molecule vacancies, and Cu active center, which help to enhance the diffusion kinetics of Zn and reduce the surface free energy of Zn electrode. Combining theoretical calculations with experiments, the HKUST-1 can contribute to the desolvation process of Zn[(HO)] and balance Zn concentration, which thus accelerate Zn transfer kinetics, lower interfacial energy, and homogenize ion-distribution. Attributed to these superiorities, the HKUST-1@Zn symmetric cells demonstrate excellent stable plating/stripping for over 250 h under ultra-high current density (20 mA/cm and 20 mAh/cm). Furthermore, a HKUST-1@Zn||MnO full cell exhibits an enhanced long-cycling performance with a discharge capacity of 114 mAh/g after undergoing 500 cycles. All results demonstrate the potential application of HKUST-1 coating in AZIBs.","PeriodicalId":18277,"journal":{"name":"Materials Today Energy","volume":"22 1","pages":""},"PeriodicalIF":9.3,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142188328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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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