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Enhanced Fatigue Property of Welded S355J2W Steel by Forming a Gradient Nanostructured Surface Layer

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Acta Metallurgica Sinica(English Letters) 2020年第9期33卷 1252-1258页

作者： Lu An Yan-Tao Sun Shan-Ping Lu zhen-bo wang Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China

Welded joints are usually characterized by microstructural and compositional inhomogeneities, which may significantly degrade their fatigue properties and result in unpredictable failures. The present work demonstrates a novel and simple method to effectively optimize the microstructure in the surface layer and promote the fatigue properties of welded specimens. By a recently developed approach—surface mechanical rolling treatment(SMRT), a gradient nanostructured surface layer is formed on welded S355 J2 W steel specimens. The mean grain size is refined to nanometer scale, and the hardness is significantly enhanced in the SMRT surface layer. Independent of the initially inhomogeneous microstructure and hardness distributions, the microstructure and hardness distributions in the surface layers are comparable on different zones of a welded specimen after SMRT with the same procedure. Consequently, fatigue property of the SMRT specimens is significantly enhanced relative to that of the as-welded specimens within the high cycle fatigue regime.

关键词： Gradient nanostructured Surface mechanical rolling treatment S355J2W steel Welded Fatigue

Cu3(PO4)2: Novel Anion Convertor for Aqueous Dual‑Ion Battery

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Nano-Micro Letters 2021年第3期13卷 1-8页

作者： Haoxiang Yu Chenchen Deng Huihui Yan Maoting Xia Xikun Zhang zhen‑bo wang Jie Shu School of Materials Science and Chemical Engineering Ningbo UniversityNingbo 315211ZhejiangPeople’s Republic of China MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage School of Chemistry and Chemical EngineeringState Key Lab of Urban Water Resource and EnvironmentHarbin Institute of TechnologyHarbin 150001HeilongjiangPeople’s Republic of China Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education) College of ChemistryNankai UniversityTianjin 300071People’s Republic of China

Electrode materials which can reversibly react with anions are of interest for aqueous dual-ion ***,we propose a novel anion electrode,Cu3(PO4)2,for constructing an aqueous dual-ion *** Cu3(PO4)2 electrode can operate in a quasi-neutral condition and deliver a reversible capacity of 115.6 mAh g^−1 with a well-defined plateau at−0.17 V versus Ag/*** reaction mechanism shows that Cu3(PO4)2 decomposes into Cu2O and subsequently is converted into Cu during the initial discharge *** the following charge process,Cu is oxidized into *** suggests Cu3(PO4)2 reacts with OH−ions instead of PO43−ions after the initial discharge process and its potential thereby depends upon the OH−ions concentration in ***,an aqueous dual-ion cell is built by using pretreated Cu3(PO4)2 and Na0.44MnO2 as anode and cathode,*** cycling,OH−ions and Na^+ions in electrolyte can be stored and *** a cell can provide a discharge capacity of 52.6 mAh g^−1 with plateaus at 0.70 and 0.45 V,exhibiting the potential of *** work presents an available aqueous dual-ion cell and provides new insights into renewable energy storage and adjustment of the OH−ions concentration in aqueous buffer solution.

关键词： Dual-ion battery Aqueous electrolyte Cu3(PO4)2 Electrochemistry Three-electrode cell

Enabling nickel ferrocyanide nanoparticles for highperformance ammonium ion storage

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Frontiers of Chemical Science and Engineering 2023年第2期17卷 226-235页

作者： Haoxiang Yu Leiyu Fan Chenchen Deng Huihui Yan Lei Yan Jie Shu zhen-bo wang MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage School of Chemistry and Chemical EngineeringState Key Lab of Urban Water Resource and EnvironmentHarbin Institute of TechnologyHarbin 150001China School of Materials Science and Chemical Engineering Ningbo UniversityNingbo 315211China

Prussian blue and its analogs are extensively investigated as a cathode for ammonium-ion ***,they often suffer from poor electronic ***,we report a Ni_(2)Fe(CN)_(6)/multiwalled carbon nanotube composite electrode material,which is prepared using a simple coprecipitation *** obtained material consists of nanoparticles with sizes 30-50 nm and the multiwalled carbon nanotube embedded in *** existence of multiwalled carbon nanotube ensures that the Ni_(2)Fe(CN)_(6)/multiwalled carbon nanotube composite shows excellent electrochemical performance,achieving a discharge capacity of 55.1 mAh·g^(-1)at 1 C and 43.2 mAh·g^(-1)even at 15 *** increase in the ammoniumion diffusion coefficient and ionic/electron conductivity based on kinetic investigations accounts for their high ***,detailed ex situ characterizations demonstrate that Ni_(2)Fe(CN)_(6)/multiwalled carbon nanotube composite offers three advantages:negligible lattice expansion during cycling,stable structure,and the reversible redox ***,the Ni_(2)Fe(CN)_(6)/multiwalled carbon nanotube composite presents a long cycling life and high rate ***,our study reports a desirable material for ammonium-ion batteries and provides a practical approach for improving the electrochemical performance of Prussian blue and its analogs.

关键词： nickel ferrocyanides NH_(4)^(+) electrochemistry Prussian blue aqueous ammonium ion batteries

Oxidization-induced structural optimization of Ni_(3)Fe-N-C derived from 3D covalent organic framework for high-efficiency and durable oxygen evolution reaction

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Nano Research 2023年第5期16卷 6710-6720页

作者： Haibing Meng Bin Wu Tianxiao Sun Long Wei Yunlong Zhang bo Liu Kai Chen zhen-bo wang Shuhui Sun Chunru wang Xian-Ming Zhang College of Chemistry Taiyuan University of TechnologyTaiyuan 030024China Helmholtz-Zentrum Berlin für Materialien und Energie GmbH Albert-Einstein-Straße 15Berlin 12489Germany Institute of Physics Humboldt University BerlinNewton-Straße 15Berlin 12489Germany National Synchrotron Radiation Laboratory University of Science and Technology of ChinaHefei 230026China MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage School of Chemistry and Chemical EngineeringHarbin Institute of TechnologyHarbin 150001China Institute National de La Recherche Scientifique(INRS)-CentreÉnergie Matériaux Télécommunications VarennesQC J3X 1P7Canada Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Molecular Nanostructure and NanotechnologyInstitute of ChemistryChinese Academy of SciencesBeijing 100190China

NiFe composites have been regarded as promising candidates to replace commercial noble-based electrocatalysts for the oxygen evolution reaction(OER).However,their practical applications still suffer from poor conductivity,limited activity,*** address these issues,herein,by utilizing three-dimensional covalent organic framework(3D-COF)with porous confined structures and abundant coordinate N sites as the precursor,the partially oxidized Ni_(3)Fe nanoalloys wrapped by Ndoped carbon(N-C)layers are constructed via simple pyrolysis and subsequent *** from the 3D curved hierarchical structure,high-conductivity of Ni_(3)Fe and N-C layers,well-distributed active sites,the as-synthesized O-Ni_(3)Fe-NC catalyst demonstrates excellent activity and durability for catalyzing *** and theoretical analyses disclose that both high-temperature oxidization and the OER process greatly promote the formation and exposure of the Ni(Fe)OOH active species as well as lower charge transfer resistance,inducing its optimized OER *** robust graphitized N-C layers with superior conductivity and their couplings with oxidized Ni_(3)Fe nanoalloys are beneficial for stabilizing catalytic centers,thereby imparting O-Ni_(3)Fe-N-C with such outstanding *** work not only provides a rational guidance for enriching and stabilizing high-activity catalytic sites towards OER but also offers more insights into the structural evolution of NiFe-based OER catalysts.

关键词： three-dimensional covalent organic framework(3D-COF) Ni_(3)Fe graphitized N-C layer structure optimization durability

A phosphotungstic acid coupled silica-Nafion composite membrane with significantly enhanced ion selectivity for vanadium redox flow battery

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Journal of Energy Chemistry 2020年第2期29卷 177-184页

作者： Xiao-Bing Yang Lei Zhao Kokswee Goh Xu-Lei Sui Ling-Hui Meng zhen-bo wang MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage School of Chemistry and Chemical EngineeringHarbin Institute of TechnologyHarbin 150001HeilongjiangChina

An ultra-high ion-selective Nafion composite membrane modified by phosphotungstic acid(PWA)coupled silica for vanadium redox flow battery(VRB)was constructed and prepared through solution *** composite membrane exhibits excellent proton conductivity and vanadium ions blocking property by incorporating the nanohybrid composed of silica and PWA into the Nafion *** tuning for the filling amount of the nanohybrid endows the obtained membranes preeminent vanadium barrier property including a minimum vanadium permeability of 3.13×10-7cm2min-1and a maximum proton conductivity of 0.081 S cm-1at 25°*** indicate an ion selectivity of 2.59×105S min cm-3,which is 6.8times higher than that of recast Nafion(0.33×105S min cm-3).As a result,the VRB with the composite membrane shows superior battery performance containing a lower self-discharge rate,higher capacity retention and more robust cyclic stability compared with recast Nafion over a range of current densities from 40 to 100 m A cm-2.

关键词： Vanadium redox flow battery Modified silica Phosphotungstic acid Low vanadium permeability

Understanding Li roles in chemical reversibility of O2-type Li-rich layered cathode materials

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Journal of Energy Chemistry 2022年第3期31卷 666-675,I0018页

作者： Jie Feng Yun-Shan Jiang Fu-Da Yu wang Ke Lan-Fang Que Jenq-Gong Duh zhen-bo wang MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage School of Chemistry and Chemical EngineeringState Key Lab of Urban Water Resource and EnvironmentHarbin Institute of TechnologyHarbin 150001HeilongjiangChina Department of Materials Science and Engineering Tsing Hua UniversityHsinchu 30010TaiwanChina College of Materials Science and Engineering Shenzhen UniversityShenzhen 518071GuangdongChina

Traditional O3-type Li-rich layered materials are attractive with ultra-high specific capacities,but suffering from inherent problems of voltage hysteresis and poor cycle *** an alternative,O2-type materials show the potential to improve the oxygen redox reversibility and structural ***,their structure-performance relationship is still ***,we investigate the correlation between the Li component and dynamic chemical reversibility of O2-type Li-rich *** exploring the formation mechanism of a series of materials prepared by Na/Li exchange,we reveal that insufficient Li leads to an incomplete replacement,and the residual Na in the Li-layer would hinder the fast diffusion of Li^(+).Moreover,excessive Li induces the extraction of interlayer Li during the melting chemical reaction stage,resulting in a reduction in the valence of Mn,which leads to a severe Jahn-Teller *** detection confirms that the regulation of Li can improve the cycle stability of Li-rich materials and suppress the trend of voltage *** reversible phase evolution observed in in-situ X-ray diffraction confirms the excellent structural stability of the optimized material,which is conducive to capacity *** work highlights the significance of modulating dynamic electrochemical performance through the intrinsic structure.

关键词： Li-ion batteries Li-rich oxide cathode O2-type Chemical reversibility Electrochemical performance

Recent advances in Pt catalysts and membrane electrode assemblies fabrication for proton exchange membrane fuel cells

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Rare Metals 2024年第9期43卷 4198-4221页

作者： Miao Ma Li-Xiao Shen Jing Liu Bin Xu Yun-Long Zhang Lei Zhao zhen-bo wang School of Chemistry and Chemical Engineering Harbin Institute of TechnologyHarbin 150001China College of Environmental and Chemical Engineering Yanshan UniversityQinhuangdao 066004China Unipower Hydrogen Technology(Jiangsu)Corporation Changzhou 213176China

Proton exchange membrane fuel cells(PEMFCs)have been identified as a highly promising means of achieving sustainable energy conversion.A crucial factor in enhancing the performance of PEMFCs for further potential energy applications is the advancement in the field of catalyst engineering that has led to remarkable performance enhancement in facilitating the oxygen reduction reaction(ORR).Subsequently,it is important to acknowledge that the techniques used in preparation of membrane electrode assemblies(MEAs),the vital constituents of PEMFCs,also possess direct and critical influence on exhibiting the full catalytic activity of meticulously crafted ***,a succinct summary of the most recent advancements in Pt catalysts for ORR was offered and their underly catalytic mechanism were ***,both laboratory-scale and industrial-scale MEA fabrication techniques of Pt catalysts were ***,a detailed analysis of the connections between materials,process,and performance in MEA fabrication was presented in order to facilitate the development of optimal catalyst layers.

关键词： Pt catalysts Oxygen reduction reaction Membrane electrode assemblies MEA fabrication techniques

Modulation of lattice oxygen boosts the electrochemical activity and stability of Co-free Li-rich cathodes

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Journal of Energy Chemistry 2022年第12期75卷 117-126,I0004页

作者： Gui-Jing Xu wang Ke Fu-Da Yu Jie Feng Yun-Shan Jiang Lan-Fang Que Lei Zhao zhen-bo wang MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage School of Chemistry and Chemical EngineeringState Key Lab of Urban Water Resource and EnvironmentHarbin Institute of TechnologyHarbin 150001HeilongjiangChina Engineering Research Center of Environment-Friendly Functional Materials Ministry of EducationInstitute of Materials Physical ChemistryHuaqiao UniversityXiamen 361021FujianChina College of Materials Science and Engineering Shenzhen UniversityShenzhen 518071GuangdongChina

Co-free Li-rich layered oxide cathodes have drawn much attention owing to their low cost and high energy ***,anion oxidation of oxygen leads to oxygen peroxidation during the first charging process,which leads to co-migration of transition metal ions and oxygen vacancies,causing structural *** this work,we propose a pre-activation strategy driven by chemical impregnation to modulate the chemical state of surface lattice oxygen,thus regulating the structural and electrochemical properties of the ***-situ X-ray diffraction confirms that materials based on activated oxygen configuration have higher structural *** importantly,this novel efficient strategy endows the cathodes having a lower surface charge transfer barrier and higher Li+transfer kinetics characteristic and ameliorates its inherent *** optimized cathode exhibits excellent electrochemical performance:after 300 cycles,high capacity(from 238 m Ah g^(-1)to 193 m Ah g^(-1)at 1 C)and low voltage attenuation(168 mV)are ***,this modulated surface lattice oxygen strategy improves the electrochemical activity and structural stability,providing an innovative idea to obtain high-capacity Co-free Li-rich cathodes for next-generation Li-ion batteries.

关键词： Pre-activation Modulation of lattice oxygen In-situ X-ray diffraction Structure stability Co-free Li-rich cathodes

Quadratic Optimization over a Second-Order Cone with Linear Equality Constraints

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Journal of the Operations Research Society of China 2014年第1期2卷 17-38页

作者： Xiao-ling Guo Zhi-bin Deng Shu-Cherng Fang zhen-bo wang Wen-xun Xing Department of Mathematical Sciences Tsinghua UniversityBeijing 100084China Industrial and Systems Engineering Department North Carolina State UniversityRaleighNC 27695USA

This paper studies the nonhomogeneous quadratic programming problem over a second-order cone with linear equality *** the feasible region is bounded,we show that an optimal solution of the problem can be found in polynomial *** the feasible region is unbounded,a semidefinite programming(SDP)reformulation is constructed to find the optimal objective value of the original problem in polynomial *** addition,we provide two sufficient conditions,under which,if the optimal objective value is finite,we show the optimal solution of SDP reformulation can be decomposed into the original space to generate an optimal solution of the original problem in polynomial ***,a recession direction can be identified in polynomial *** examples are included to illustrate the effectiveness of the proposed approach.

关键词： Quadratic programming Linear conic programming Second-order cone Cone of nonnegative quadratic functions