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Al-Doped Nb2o5/Carbon Micro-Particles Anodes for High Rate Lithium-Ion Batteries

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SSRN 2022年

作者： Zhu, Zhu Liu, Fang Wang, Hong Yu, Ruohan Wu, Jinsong State Key Laboratory of Advanced Technology for Materials Synthesis and Processing School of Materials Science and Engineering Wuhan University of Technology Hubei Wuhan430070 China Wuhan University of Technology Wuhan430070 China

Orthorhombic niobium pentoxide (T-Nb2O5 ) has attracted extensive attention in the field of ultra-fast lithium ion batteries (LIBs) due to its high rate performance. However, its instability at a low potential and inherent low conductivity limits its fast charging capability. Here, microspheres of aluminum-doped T-Nb2O5 embedded in N-doped carbon network (Al-Nb2O5@NC) are prepared. The effects of Al-doping on the crystal structure and electrochemical properties are systematically studied. It is found that Al-doping has led to increase of the density of O2- vacancies and then low-oxidized state Nb4+ ions, improving ionic and electrical conductivity. The substitution of Al3+ ions for Nb5+ ions improves the lattice stability, reduces the undesirable migration of Nb in cycling, and stabilizes the capacity during fast charging. The LIBs using Al-Nb2O5@NC as anode have high rate performance and cycling stability ( i.e. , ~82 mAh g-1 at 20 A g-1 after 9900 cycles). Meanwhile, the intercalation-type electrochemical reaction is verified by in-situ transmission electron microscope (TEM), by which it is found that Al-Nb2O5@NC has better crystalline integrity. By integrating Al doping and carbon network, the micron-size Al-Nb2O5@NC particles developed in this work are promising anodes to build fast charge/discharge LIBs with high specific capacity, stability and excellent rate performance. © 2022, The Authors. All rights reserved.

关键词： Lithium-ion batteries

Experimental Probing of the Effect of Nafion Poisoning at Different Pt Loadings in a Pemfc

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SSRN 2022年

作者： Zhou, Fen Zhang, Hui Guan, Shumeng Li, Guangfu Xia, Lei Pan, Mu Foshan Xianhu Laboratory of the Advanced Energy Science and Technology Guangdong Laboratory Xianhu Hydrogen Valley Foshan528200 China State Key Laboratory of Advanced Technology for Materials Synthesis Processing Wuhan University of Technology Wuhan430070 China

The charge-transfer resistance ( R ct ) in electrochemical impedance spectroscopy (EIS) was applied as an activity indicator to study the suppression of a rotating disk electrode (RDE) and membrane electrode assembly (MEA) by Nafion with different Pt loadings. Use of the R ct avoids uncertainty in activity characterization;such uncertainty is caused by mass transfer in highly loaded catalyst agglomerates. It was found that Nafion had a stronger poisoning effect at lower Pt loadings. The simultaneous reduction in the working voltage further aggravates the poisoning, especially under low-Pt conditions. After poisoning, the normalized R ct at 20 µg/cm 2 increased from 8 times at 0.9 V to 21 times at 0.82 V. When the Nafion adsorption coverage on the surface of Pt remained constant, the suppressed activity increased as the Pt loading decreased. Therefore, it is critical to consider Nafion poisoning when constructing MEAs with low platinum and take appropriate strategies to alleviate poisoning and achieve high-performance output. © 2022, The Authors. All rights reserved.

关键词： Proton exchange membrane fuel cells (PEMFC)

Low Pressure Chemical Vapor Deposited Perovskite Enables all Vacuum-Processed Monolithic Perovskite-Silicon Tandem Solar Cells

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advanced Energy materials 2025年

作者： Zhang, Yuxi Zhu, Yanqing Sun, Jingsong Hu, Min Chen, Jiahui Duan, Bingxin Hu, Shenghan Hou, Peiran Tan, Wen Liang Ku, Zhiliang Yang, Weiguang Lu, Jianfeng State Key Laboratory of Silicate Materials for Architectures Wuhan University of Technology Wuhan430070 China Zhejiang Baima Lake Laboratory Co. Ltd. Zhejiang Hangzhou310000 China School of Electronic and Electrical Engineering Hubei Province Engineering Research Center for Intelligent Micro-Nano Medical Equipment and Key Technologies Wuhan Textile University Wuhan430200 China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan430070 China ClaytonVIC3168 Australia Solar Technology Co. Ltd. Jiangsu Taizhou225500 China

Low-pressure chemical vapor deposition (CVD) is a promising technique for metal halide perovskite photovoltaics fabrication due to its low manufacturing cost, conformal coverage, and high scalability for industry-scale fabrication. However, the lack of knowledge of the reaction kinetics makes the solar cell performance lag behind its solution-processed counterpart. Herein, the perovskite formation and crystal growth process in the CVD process are studied by unraveling the mechanism of ion diffusion via tracking the vapor–solid reaction with various semi-in-situ characterizations. It is found that Cs+ can migrate along the perovskite lattice and uniformly distribute in the vertical direction of the final perovskite film even changing the deposition order of CsBr and PbI2 in the solid source, whereas this order can significantly affect the growth kinetics and the bandgap of the perovskite. Depositing CsBr before PbI2 results in a faster conversion of inorganic precursors to perovskite phase, yielding a wider bandgap perovskite. Finally, we fabricated semi-transparent perovskite cells using all-vapor deposition process, which showed a champion efficiency of 18.7% and it retained ≈94% of its initial performance after 200 h of continuous operation. Moreover, using this all-vapor deposition process, we achieved a champion efficiency of 26.9% for monolithic perovskite-silicon tandem solar cells. © 2025 Wiley-VCH GmbH.

关键词： Low pressure chemical vapor deposition

Hydrophilic bi-functional B-doped g-C_(3)N_(4) hierarchical architecture for excellent photocatalytic H_(2)O_(2) production and photoelectrochemical water splitting

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Journal of Energy Chemistry 2022年第7期31卷 236-247,I0007页

作者： Yang Ding Soumyajit Maitra Chunhua Wang Runtian Zheng Meiyu Zhang Tarek Barakat Subhasis Roy Jing Liu Yu Li Tawfique Hasan Bao-Lian Su Laboratory of Inorganic Materials Chemistry(CMI) University of Namur61 rue de BruxellesB-5000 NamurBelgium Namur Institute of Structured Matter(NISM) University of Namur61 rue de BruxellesB-5000 NamurBelgium Department of Chemical Engineering University of Calcutta92 APC RoadWest BengalKolkata 700009India Department of Chemistry KU LeuvenCelestijnenlaan 200FB-3001 LeuvenBelgium State Key Laboratory of Applied Organic Chemistry Key Laboratory of Nonferrous Metals Chemistry and Resources Utilization of Gansu ProvinceCollege of Chemistry and Chemical EngineeringLanzhou UniversityLanzhou 730000GansuChina State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070HubeiChina Cambridge Graphene Centre University of CambridgeCambridgeCB30DSUK Clare Hall University of CambridgeUnited KingdomCB21EWUK

Graphitic carbon nitride(g-C_(3)N_(4))has attracted great interest in photocatalysis and ***,their poor hydrophilicity poses a great challenge for their applications in aqueous ***,we demonstrate synthesis of a hydrophilic bi-functional hierarchical architecture by the assembly of B-doped g-C_(3)N_(4)*** hierarchical B-doped g-C_(3)N_(4)material enables full utilization of their highly enhanced visible light absorption and photogenerated carrier separation in aqueous medium,leading to an excellent photocatalytic H_(2)O_(2)production rate of 4240.3μM g^(-1)h^(-1),2.84,2.64 and 2.13 times higher than that of the bulk g-C_(3)N_(4),g-C_(3)N_(4)nanoplatelets and bulk B doped g-C_(3)N_(4),*** based on these hierarchical architectures can generate an unprecedented photocurrent density of 1.72 m A cm^(-2)at 1.23 V under AM 1.5 G illumination for photoelectrochemical water *** work makes a fundamental improvement towards large-scale exploitation of highly active,hydrophilic and stable metal-free g-C_(3)N_(4)photocatalysts for various practical applications.

关键词： Boron doping Hydrophilicity Hierarchically assembled architectures Photocatalytic H_(2)O_(2)production Photoelectrocatalytic water splitting

In-Situ Transformation and Synergistic Electrocatalysis of Asymmetric Threefold Hollow Sites in Rosebud-Like Ternary Metal Diselenide

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SSRN 2024年

作者： Wang, Shihao Liao, Lin Wu, Jinsong Tang, Haolin Zhang, Haining State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Hubei Wuhan430070 China National Energy Key Laboratory for New Hydrogen-Ammonia Energy Technologies Foshan Xianhu Laboratory Guangdong Foshan528200 China International School of Materials Science and Engineering School of Materials and Microelectronics Wuhan University of Technology Hubei Wuhan430070 China Nanostructure Research Centre Wuhan University of Technology Hubei Wuhan430070 China Hubei Key Laboratory of Fuel Cell Wuhan University of Technology Hubei Wuhan430070 China

Electrochemical dynamic reconstruction substantially optimizes the catalytic properties of transition-metal-based precatalysts for the multi-electron oxygen evolution reaction (OER) by altering the surface structure, exposing more active sites, improving electron/ion transport, and enhancing stability. This research provides a comprehensive understanding of the in-situ transformation manner of a rosebud-like ternary metal diselenide precatalyst (Ni0.8Fe0.2Co0.1Se2) and the synergistic electrocatalytic mechanism of catalytic active centers through in-situ and ex-situ characterization along with DFT calculations. Benefiting from the unique morphology and abundant nanoscale planar defects within the conductive Ni0.8Fe0.2Co0.1Se2 core and the in-situ formed catalytically active (Fe, Co)-doped γ-NiOOH shell, the reconstructed catalyst achieves rapid electron/ion transport and copious active site exposure. Accordingly, the Ni0.8Fe0.2Co0.1Se2 catalyst only requires overpotentials of 101 mV and 233 mV to achieve current densities of 10 mA cm−2 and 100 mA cm−2, respectively. The overall water-splitting cell using Ni0.8Fe0.2Co0.1Se2 anode delivers current densities of 10 and 100 mA cm−2 at low cell voltages of 1.41 and 1.56 V, respectively. Furthermore, the cell demonstrates exceptional durability of 400 h at an industrial-level current density. This work sheds light on the development of efficient transition-metal-based precatalysts for OER. © 2024, The Authors. All rights reserved.

关键词： Iron compounds

Development of innovative and green adsorbents for in situ cleanup of fluoride-polluted groundwater: Mechanisms and field-scale studies

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Chemosphere 2024年 350卷 141035页

作者： Ou, Jiun-Hau Wang, Chih-Chieh Verpoort, Francis Chien, Chih-Ching Zhong, Hua-Bin Kao, Chih-Ming Institute of Environmental Engineering National Sun Yat-Sen University Kaohsiung Taiwan Hershey Environmental Technology Corp. Ltd. Kaohsiung Taiwan State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan China Graduate School of Biotechnology and Bioengineering Yuan Ze University Chung-Li City Taoyuan Taiwan

In this study, the magnesium oxide (MgO)-based adsorbents [granulated MgO aggregates (GA-MgO) and surface-modified MgO powder (SM-MgO)] were developed to remediate a fluoride-contaminated groundwater site. Both GA-MgO and SM-MgO had porous, spherical, and crystalline structures. Diameters for GA-MgO and SM-MgO were 1–1.7 mm and 1–10 μm, respectively. The pseudo second-order dynamic adsorption and the Freundlich isotherm could be applied to express the chemical adsorption phenomena. The monolayer adsorption was the dominant mechanism at the initial adsorption period. During the latter part of fluoride adsorption, the multilayer adsorption became the dominant mechanism for fluoride removal from the water phase, which also resulted in the increased adsorption capacity. Higher hydroxide, phosphate, and carbonate concentrations caused a decreased fluoride removal efficiency due to the competition of sorption sites between fluoride and other anions with similar electronic properties. Fluoride removal mechanism using GA-MgO and SM-MgO as the adsorbents was mainly carried out by the chemical adsorption. Reaction paths contained two main processes: (1) formation of magnesium hydroxide after the reaction of MgO with water, and (2) the hydroxyl group of the magnesium hydroxide was replaced by fluoride ions to form magnesium fluoride precipitation. Results from column tests show that up to 61 and 73% of fluoride removal (initial fluoride concentration = 9.3 mg/L) could be obtained after 50 pore volumes of groundwater pumping with GA-MgO and SM-MgO injection, respectively. The GA-MgO system could be applied to contain and remediate fluoride-contaminated groundwater, and SM-MgO could be applied as an immediate fluoride removal alternative to achieve a rapid pollutant removal for emergency responses. Up to 71% of fluoride removal (fluoride concentration = 10.8 mg/L) could be obtained with GA-MgO injection after 30 days of operation. The developed GA-MgO system is a potential and g

关键词： Magnesia

Na doping and CeO2 surface modification enhancing the Li-rich Li1.2Mn0.54Ni0.13Co0.13O2 cathode material for lithium-ion battery

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SSRN 2024年

作者： Li, Yu Feng, Xiang-Yu Ran, Mao-Jin Yuan, Man-Man Wei, Mei-Tong Wu, Liang Hu, Zhi-Yi Chen, Li-Hua Su, Bao-Lian State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan430070 China Wuhan University of Technology Wuhan430070 China School of Automotive Engineering Xiangyang Polytechnic 18 Longzhong Road Hubei Xiangyang441050 China University of Namur NamurB-5000 Belgium

Li-rich Mn-based layered oxides with high specific capacity and operating voltages become one of the most promising materials for lithium-ion batteries (LIBs). However, it still faces several issues on low initial coulombic efficiency, poor electronic conductivity and voltage fading due to oxygen release and transition metals rearrangement during cycling. In this study, Li1.2Mn0.54Ni0.13Co0.13O2 (LMR) cathode material with Na ion doping (LMNaR) and CeO2 surface modification (LMNaR@CeO2) is prepared to realize the synergistic modification effect. The doping of Na ions enlarges Li layer spacing to effectively promote the insertion and extraction of lithium ions, which makes the layered structure more stable to reduce the effect of phase transition. And the CeO2 surface modification restrains the side reactions between electrode and electrolyte, and stabilizes lattice oxygen and eases oxygen release. As a result, the LMNaR@CeO2 displays a specific capacity of 196 mAh·g-1 after 100 cycles at 0.5 C with a capacity retention of 94% and a merely voltage decay of 0.16 V, which are much better than the LMR with a specific capacity of 159.6 mAh·g-1 and only a 79% capacity retention. Our strategy here provides a feasible approach for the development of Li-rich Mn-based anode materials for long life LIBs. © 2024, The Authors. All rights reserved.

关键词： Lithium-ion batteries

Na Doping and Ceo2 Coating Enhancing the Li-Rich Li1.2mn0.54ni0.13co0.13o2 Cathode Material for Lithium-Ion Battery

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SSRN 2024年

作者： Li, Yu Feng, Xiang-Yu Ran, Mao-Jin Yuan, Man-Man Peng, Yan Luo, Bi-Cheng Wei, Mei-Tong Wu, Liang Hu, Zhi-Yi Chen, Li-Hua Su, Bao-Lian State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan430070 China Wuhan University of Technology Wuhan430070 China School of Automotive Engineering Xiangyang Polytechnic 18 Longzhong Road Hubei Xiangyang441050 China University of Namur NamurB-5000 Belgium

Li-rich Mn-based layered oxides with high specific capacity (>250 mAh·g-1) and operating voltages become one of the most promising materials for lithium-ion batteries (LIBs). However, it still faces several issues on low initial coulombic efficiency, poor electronic conductivity and voltage fading due to oxygen release and transition metals rearrangement during cycling. In this study, Li1.2Mn0.54Ni0.13Co0.13O2 (LMR) cathode material with Na ion doping (LMNaR) and surface CeO2 coating (LMNaR@CeO2) is successfully prepared via a simple co-precipitation and wet chemical to realize the synergistic modification effect. On one hand, the doping of Na ions enlarges Li layer spacing to effectively promote the insertion and extraction of lithium ions. Meanwhile, due to the larger radius of Na ions, the layered structure becomes more stable, thus reducing the effect of phase transition. On the other hand, the CeO2 coating layer restrains the side reaction between electrode and electrolyte, and stabilizes lattice oxygen and eases oxygen release. The electrochemical results illustrate that the LMNaR@CeO2 exhibits outstanding electrochemical capabilities. Notably, it displays a specific capacity of 196 mAh·g-1 after 100 cycles at 0.5 C with a capacity retention of 94% and a merely voltage decay of 0.16 V, which are much better than the LMR with a specific capacity of 159.6 mAh·g-1 and only a 79% capacity retention. Our strategy here provides a feasible approach for the development of Li-rich Mn-based anode materials for long life LIBs. © 2024, The Authors. All rights reserved.

关键词： Lithium-ion batteries

Hierarchically Porous Few-Layer Carbon Nitride and Its High H+Selectivity for Efficient Photocatalytic Seawater Splitting

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Nano Letters 2023年第10期23卷 4390-4398页

作者： Shi-Tian Xiao Rui Yin Lu Wu Si-Ming Wu Ge Tian Menny Shalom Li-Ying Wang Yi-Tian Wang Fu-Fei Pu Hannah-Noa Barad Fazhou Wang Xiao-Yu Yang State Key Laboratory of Advanced Technology for Materials Synthesis and Processing & School of Materials Science and Engineering & State Key Laboratory of Silicate Materials for Architectures & Shenzhen Research Institute Wuhan University of Technology Wuhan 430070 China Key Laboratory for the Synthesis and Application of Organic Functional Molecules Ministry of Education College of Chemistry and Chemical Engineering Hubei University Wuhan 430062 China Department of Chemistry and Ilse Katz Institute for Nanoscale Science and Technology Ben-Gurion University of the Negev Beer-Sheva 8410501 Israel State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics National Center for Magnetic Resonance in Wuhan Wuhan Institute of Physics and Mathematics Innovation Academy for Precision Measurement Science and Technology Chinese Academy of Sciences Wuhan 430071 China Department of Chemistry Institute of Nanotechnology & Advanced Materials Bar Ilan University Ramat Gan 5290002 Israel

Photocatalysts for seawater splitting are severely restricted because of the presence of multiple types of ions in seawater that cause corrosion and deactivation. As a result, new materials that promote adsorption of H+and hinder competing adsorption of metal cations should enhance utilization of photogenerated electrons on the catalyst surface for efficient H2production. One strategy to design advanced photocatalysts involves introduction of hierarchical porous structures that enable fast mass transfer and creation of defect sites that promote selective hydrogen ion adsorption. Herein, we used a facile calcination method to fabricate the macro–mesoporous C3N4derivative, VN-HCN, that contains multiple nitrogen vacancies. We demonstrated that VN-HCN has enhanced corrosion resistance and elevated photocatalytic H2production performance in seawater. Experimental results and theoretical calculations reveal that enhanced mass and carrier transfer and selective adsorption of hydrogen ions are key features of VN-HCN that lead to its high seawater splitting activity.

关键词： Adsorption Defects in solids Ions Nitrogen Seawater