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Surface-assembled highly flexible Na_(3)(VOPO_(4))_(2)F nanocube cathode for high-rate binder-free Na-ion batteries

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Chinese Chemical Letters 2021年第2期32卷 826-829页

作者： Bohua Deng Ning Yue Haoyang Dong Qiuyue Gui Liang Xiao Jinping Liu School of Chemistry Chemical Engineering and Life ScienceWuhan University of TechnologyWuhan 430070China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology.Wuhan 430070China Key Laboratory for Photonic and Electronic Bandgap Materials Ministry of EducationSchool of Physics and Electronic EngineeringHarbin Normal UniversityHarbin 150025China

Flexible Na-ion storage cathodes are still very few due to the challenge in achieving both reliable mechanical flexibility and excellent electrochemical ***,a new type of flexible Na_(3)(VOPO_(4))_(2)F cathode with nanocubes tightly assembled on carbon cloth is fabricated by a facile solvothe rmal method for the first *** cathode is able to exhibit superior rate capability and stable cycling performa nce up to 1000 cycles,due to the surface-assembling of crystalline nanocubes on carbon *** addition,it shows good mechanical flexibility,nearly no capacity decay is observed after continuous bending of 500 *** this novel cathode and a directly-grown Na_(2)Ti_(2)O_(5) anode,a fully binde r-free Na-ion battery is *** can deliver a high wo rking voltage and increased gravimetric energy/power densities(maximum values:220.2 Wh/kg;5674,7 W/kg),and can power a LED indicator at bending angles fro m 0° to 180°.

关键词： Flexible cathode Na_(3)(VOPO_(4))_(2)F Nanocube Surface-assembling Sodium-ion battery

Simpler and Greener Preparation of An In-Situ Polymerized Polyimide Anode for Lithium Ion Batteries

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SSRN 2023年

作者： Zhang, Qiuyitong Xu, Yuexin Lv, Ning Li, Hanyang Wei, Zijie Tiana, Tian Wang, Yadong Tang, Haolin State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan430070 China Foshan Xianhu Laboratory of the Advanced Energy Science and Technology Guangdong Laboratory Xianhu Hydrogen Valley Foshan528200 China

A simplified and greener procedure for in-situ obtaining polyimide anode materials for lithium-ion battery electrodes is developed. The combined polyimide material synthesis and electrode preparation reduces the number of processing steps and treatment duration and decreases the energy required for heat treatment, solvent evaporation, and organic solvent use. More importantly, polymerization in situ on the electrode surface render the polyimide particles a sea urchin-like structure, leading to fast electrochemical kinetics, and significant improvement in discharge capacity and cycling performance compared with materials obtained using traditional procedures. Specific capacities of 1870 mAh g-1 and 2277 mAh g-1 at 30℃ and 60℃, respectively, are obtained. A capacity of 1774 mAh g-1 is retained after 500 cycles at high current density of 1000 mA g-1 at 60℃. This new preparation process not only simplifies the preparation process and makes it greener, but also significantly improves the battery performance, providing new possibilities for the preparation of high-performance low-cost lithium-ion battery electrodes. © 2023, The Authors. All rights reserved.

关键词： Solvents

Hierarchical Microstructure and Strengthening Mechanism of Haynes 188 Alloy Manufactured by Laser Powder Bed Fusion

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SSRN 2022年

作者： Liu, Yang Huang, Zhifeng Zhang, Chi Lu, Jiaqi Ouyang, Ni Shen, Qiang Chen, Fei State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan430070 China

Co and Ni superalloys have been widely used in aerospace. Abundant studies have been focused on additive manufacturing of Ni superalloys. However, the equally important Co superalloy has less been fabricated by additive manufacturing. In this work, Haynes 188 alloy, a kind of Co-based superalloy, is fabricated by using laser powder bed fusion. The microstructure and mechanical properties before and after a stress relief treatment of the additive manufactured Haynes 188 alloys are investigated in detail. For as-built alloys without stress relief treatment, the thermodynamic modeling predicts that a phase of M 6 C exists in the specimen, which is confirmed by a TEM EDS mapping result. Arrayed stacking faults, dislocations, and M 6 C precipitations are widely found inside grains of the specimen without stress relief treatment. The yield strength and elongation of the specimen without stress relief treatment are 645 MPa and 57.3%, respectively. For the specimen with stress relief treatment, the dislocation density is reduced, the carbide precipitations are dissolved into the matrix, and stacking faults are arrayed near grain boundaries. As a result, the yield strength slightly decreases to 485 MPa but the elongation increases to 68.1%. The mechanical properties of fabricated Haynes 188 alloys in this work are superior to that of the published Ni or Co superalloys. This work provides an effective method to improve the mechanical properties of Co superalloys by additive manufacturing, which is important for the development of high-performance superalloys and their manufacturing methods. © 2022, The Authors. All rights reserved.

关键词： Superalloys

Enhancing the Combustion Properties of Interface Optimized Metastable Intermixed Composites Pvdf/Μ-Al by Noncovalently Functionalized Graphene

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SSRN 2022年

作者： Shen, Qiang Yi, Zhuoran Deng, Haoyuan Qin, Mei Sun, Yi Luo, Guoqiang State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan430070 China

Energetic metastable intermixed composites (MICs) consisting of polyvinylidene fluoride (PVDF) and fuels aluminum (Al) have the potential to be used as propellants and explosives. Our study introduced SPEEK-modified graphene (SPG) prepared by non-covalent modification of sulfonated poly(ether-ether-ketone) (SPEEK) into PVDF/Al to improve its energy release. The optimized interface generated by the interaction between SO3H groups of SPG layer and CF2 dipoles of PVDF layer integrates graphene onto the surface of PVDF/Al particles. Due to the effect of graphene on the interfacial thermal resistance, the enthalpy of SPG coated PVDF/Al particles is about 1.5 times higher than that of uncoated particles. The existence of SPG improves the heat transfer efficiency of MICs. For comparison, reduced graphene oxide (RGO) has also been introduced as an additive. Graphene is introduced to linearly affect(R2=0.9865) the main oxidation enthalpy by lifting the surface oxidation heat release of the Al core. Therefore, graphene is a new strategy for increasing the energy release rate while improving the energy output. © 2022, The Authors. All rights reserved.

关键词： Graphene

Polyphenol Synergistic Cerium Oxide Surface Engineering Constructed Core-Shell Nanostructures as Antioxidants for Durable and High-Performance Proton Exchange Membrane Fuel Cells

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SSRN 2023年

作者： Tang, Haolin Zhao, Shengqiu Liao, Yucong Wang, Rui Liu, Guoliang Zhang, Haining State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan430070 China Foshan Xianhu Laboratory The Advanced Energy Science and Technology Guangdong Laboratory Xianhu Hydrogen Valley Foshan528200 China

The chemical degradation of proton exchange membranes (PEMs) suffering from radical attack is a crucial issue in the development of proton exchange membrane fuel cells (PEMFCs), while incorporating cerium oxide (CeO2) nanoparticles (NPs) with regenerative redox properties to eliminate radicals could effectively alleviate degradation. However, the low stability and restricted activity of CeO2 in the PEMFC operating condition and the poor compatibility with PEM due to CeO2 agglomeration stimulate the urgency for structural modulation of CeO2. Herein, polyphenols surface functionalized CeO2 core-shell structure (CeO2@TP) were constructed via assembling oxidation-induced coupling tea polyphenols (TP) on CeO2 NPs. The TP oligomeric shell as a protective layer enhances the stability of CeO2, mitigating radical scavenging activity degradation and improving compatibility with PEMs. Gratifyingly, the phenolic hydroxyl-rich reductive TP oligomeric shell accelerates the regeneration of Ce(IV) to Ce(III), increasing the proportion of Ce(III) and oxygen vacancies on the CeO2 surface, thus boosting antioxidation efficiency. As a result, the CeO2@TP-based PEMs exhibited an OCV decay rate of 0.22 mV h-1, a maximum power density of 1.06 W cm-2, an H2 crossover value of 2.18 mA cm-2, thickness retention (91.1%), and negligible Ce migration after 404 hours of accelerated degradation testing. © 2023, The Authors. All rights reserved.

关键词： Oligomers

Boosting the Antioxidant Efficiency of Ce(Iii)-Based Organometallic Complexes Via Ion-Limited Domain and Electronic Structure Modulation Towards Robust Proton Exchange Membrane Fuel Cells

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SSRN 2023年

作者： Zhao, Shengqiu Liao, Yucong Wang, Rui Li, Hao Zhang, Haining Tang, Haolin State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan430070 China Foshan Xianhu Laboratory The Advanced Energy Science and Technology Guangdong Laboratory Xianhu Hydrogen Valley Foshan528200 China

Ce-based radical scavengers, including free Ce3+, are highly efficient radical scavengers with rapid and regenerative redox properties that can enhance the chemical durability of prton exchange membranes (PEMs). However, during the proton exchange membrane fuel cell (PEMFC) operation, water-soluble free Ce3+ ions in PEMs irreversibly migrate away and poison the proton-conducting ion clusters, leading to a decline in PEMFC output power. Herein, organometallic complexes of Ce3+ ions (Ce/HMCRE) derived by Ce3+ ions coordinating with 2-hydroxymethyl-15-crown-5 ether (HMCRE) ligands were utilized as FRS for improving the stability of PEMs. Owing to the coordination between the crown ether oxygen atom of the ligand and the Ce3+, the migration of Ce3+ and the adverse interactions among Ce3+ ions with the sulfonic group of PEM was inhibited. Meanwhile, the formation of coordination bonds allows the central Ce3+ ion to accept electrons on the ligand oxygen atom, thus enhancing the antioxidant efficiency of Ce/HMCRE. Gratifyingly, the hydrogen bonding between the hydroxymethyl group of the HMCRE ligand and the ether oxygen atom on the side chain of the perfluorosulfonic acid (PFSA) matrix also contributes to anchoring the Ce/HMCRE complex and mitigating its interference with ion clusters of PEM. Consequently, the Ce/HMCRE-based hybrid PEMs demonstrated an OCV decay rate of 0.45 mV h-1, a maximum power density of 1.07 W cm-2, an H2 crossover value of 2.41 mA cm-2, a thickness retention of 92% after 150 hours of accelerated degradation testing. © 2023, The Authors. All rights reserved.

关键词： Ligands

Metal Alkoxides: A New Type of Reversible Anode materials for Stable and High-Rate Lithium-Ion Batteries

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SSRN 2024年

作者： Huang, Shaozhuan Deng, Chengjiang Ma, Liuyuan Liu, Jiayan Han, Xiaoyan Zhang, Qing Jin, Jun Li, Yu Key Laboratory of Catalysis and Energy Materials Chemistry of Ministry of Education Hubei Key Laboratory of Catalysis and Materials Science South-Central Minzu University Wuhan430074 China Faculty of Materials Science and Chemistry China University of Geosciences Wuhan430074 China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan430070 China

Metal-organic compounds have attracted significant attention for lithium-ion battery (LIB) anodes. However, their practical application is severely hindered by the poor structure stability and sluggish Li+ reaction kinetics. Here, we proposed a new type of metal-organic compound, metal alkoxides, for high-performance LIBs. A series of metal-alkoxide/graphene composites with different transition metal centers and alkoxide anions are prepared to investigate the structural stability, Li-storage ability, and Li+ diffusion kinetics. The results reveal that the metal centers and alkoxide anions have significant influence on the structural stability, molecular weight, and electronic structures, which are highly related to the Li-storage performance. Among them, Co-EG/rGO (EG represents the ethylene glycol anion) delivers the best performance involving high specific capacity (975 mAh g-1 at 0.2 A g-1), excellent rate capability (400.8 mAh g-1 at 10 A g-1), and stable cycling performance (86.8% capacity retention after 600 cycles) due to its stable structure, smaller molecular weight, and favorable electronic structure. Moreover, the Li-storage mechanism and solid electrolyte interphase (SEI) evolution of the Co-EG/rGO electrode are studied in detail through multiple ex-situ/in-situ characterizations. This work provides a new type of metal alkoxide anode material for high-rate and long-life LIBs toward practical energy applications. © 2024, The Authors. All rights reserved.

关键词： Lithium-ion batteries

Ultrafine Grain Tungsten Heavy Alloys with Excellent Performance Prepared by Spark Plasma Sintering

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Journal of Wuhan University of technology(materials Science) 2020年第2期35卷 393-398页

作者： ZHANG Jingang WANG Weimin JI Wei HE Qianglong WANG Aiyang TAN Lin YANG Kai State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Institute of Material Science and EngineeringWuhan University of TechnologyWuhan 430070China

Ultrafine grain tungsten heavy alloys (WHAs) were successfully produced from the nano-crystalline powders using spark plasma *** present study mainly discussed the effects of sintering temperature on the density,microstructure and mechanical properties of the *** relative density of 98.12% was obtained at 1 050 ℃,and the tungsten grain size is about 871 *** 1 000 ℃-1 200 ℃,the mechanical properties of the alloys tend to first rise and then goes *** SPS,the alloy exhibits improved hardness (84.3 HRA at 1 050 ℃) and bending strength (987.16 MPa at 1 100 ℃),due to the ultrafine-grained *** fracture mode after bending tests is mainly characterized as intergranular or intragranular fracture of W grains,interfacial debonding of W grains-binding phase and ductile tearing of binding *** EDS analysis reveals a certain proportion of solid solution between W and Ni-Fe binding *** good mechanical properties of the alloys can be attributed to grain refinement and solid solution strengthening.

关键词： tungsten heavy alloys ultrafine grain nano-crystalline powders solid solution strengthening spark plasma sintering

Enhanced photocatalytic activity and mechanism of CeO_(2) hollow spheres for tetracycline degradation

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Rare Metals 2021年第9期40卷 2369-2380页

作者： Dan Wang Fang-Xin Yin Bei Cheng Yang Xia Jia-Guo Yu Wing-Kei Ho State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China School of Materials Science and Engineering Zhengzhou UniversityZhengzhou 450001China Department of Science and Environmental Studies The Education University of Hong KongTai Po 999077Hong KongChina State Key Laboratory of Marine Pollution City University of Hong KongKowloon 999077Hong KongChina

Recently, researchers have focused on designing and fabricating highly efficient catalysts for photocatalytic organic pollutant removal. Herein, CeO_(2) hollow spheres were prepared through a simple template method followed by calcination at different temperatures for the tetracycline(TC) degradation under simulated solar light illumination. With a calcination temperature ranging from400 to 800 ℃, the as-prepared CeO_(2) hollow structure annealed at 600 ℃(C_(600)) exhibited the best degradation performance with a degradation rate constant of0.066 min-1, which was about six and five times higher than those of the uncalcined sample(C_(0)) and the sample calcined at 800 ℃(C_(800)), respectively. Moreover, sample C_(600)was also superior to the CeO_(2) solid particle photocatalyst. The characterisation results showed that the improved photocatalytic performance was mainly ascribed to the synergistic effect of large specific surface areas, high crystallisation and excellent light scattering ability. Furthermore, the results of active species trapping experiments demonstrated that the superoxide anion(·O_(2)^(-)) radical and hole(h^(+)) played dominant roles in TC degradation. Subsequently, the possible TC degradation pathways and photocatalytic mechanism of CeO_(2) hollow spheres were proposed on the basis of high-performance liquid chromatography–mass spectrometry analysis, main active species and band edge positions of CeO_(2). The results of this study provide a basis for designing and exploring hollow structure catalysts for energy conversion and environmental remediation.

关键词： CeO_(2)hollow spheres Photocatalytic degradation Tetracycline Mechanism Reaction pathway