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Revealing the working mechanism of a multi-functional block copolymer binder for lithium-sulfur batteries

2009水资源与可持续发展高层论坛

作者： liu Huihai~(1+),ZHANG Renduo~2 (1.Earth Science Division,lawrence berkeley national laboratory,berkeley,california 94720,usa 2.School of Environmental Science and Engineering,Sun Yat-Sen University,Guangzhou 510275,P.R. China)

＜正＞Preferential flow commonly observed in unsaturated soils allows rapid movement of solute from the ground surface or vadose zone to the groundwater,bypassing a significant volume of unsaturated soil and increasing the risk of groundwater contamination.A variety of evidence indicates that complex preferential flow patterns observed from fields are fractals. This paper discusses a macroscopic relationship for modeling preferential flow in the vadose ***,the flow domain can be divided into active and inactive *** occurs preferentially in the active region（characterized by fractals）,and inactive region is simply *** portion of the active region was found to be a power function of *** validity of this macroscopic relationship is demonstrated by its consistency with field observations and the related numerical experiments.

关键词： preferential flow constitutive relations vadose zone hydrology

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Journal of Energy Chemistry 2021年第8期30卷 1-8,I0001页

作者： Xin He Zhimeng liu Guoping gao Xiaotao liu Michal Swietoslawski Jun Feng gao liu Lin-Wang Wang Robert Kostecki Energy Storage&Distributed Resources Division Lawrence Berkeley National Laboratory1 Cyclotron Road94720 BerkeleyUSA Materials Sciences Division Lawrence Berkeley National Laboratory94720 BerkeleyUSA The Molecular Foundry Lawrence Berkeley National Laboratory94720 BerkeleyUSA Department of Materials Science&Engineering Southern University of Science and Technology(SUSTech)Shenzhen 518055China

The lithium-sulfur(Li-S)battery is one of the most promising substitutes for current energy storage systems because of its low cost,high theoretical capacity,and high energy ***,the high solubility of intermediate products(i.e.,lithium polysulfides)and the resultant shuttle effect lead to rapidly fading capacity and a low coulombic efficiency,which hinder the practical application of Li-S *** this study,block copolymers are constructed with both an ethylene oxide unit and a styrene unit and then used as binders for Li-S *** performance improvements are attributed to the synergistic effects contributed by the different units of the block *** ethylene oxide unit traps polysulfide,which bonds strongly with the intermediate lithium polysulfide,and enhances the transport of lithium ions to reach high ***,the styrene unit maintains cathode integrity by improving the mechanical properties and elasticity of the constructed block copolymer to accommodate the large volume *** enabling multiple functions via different units in the polymer chain,high sulfur utilization is achieved,polysulfide diffusion is confined,and the shuttle effect is suppressed during the cycle life of Li-S batteries,as revealed by operando ultraviolet-visible spectroscopy and S Kedge X-ray absorption spectroscopy.

关键词： Lithium sulfur batteries Polymer binder Block copolymer Ultraviolet-visible spectroscopy X-ray absorption spectroscopy

Investigating the impact of air pollution on AMI and COPD hospital admissions in the coastal city of Qingdao,China

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Frontiers of Environmental Science & Engineering 2022年第5期16卷 13-25页

作者： Jiuli Yang Mingyang liu Qu Cheng Lingyue Yang Xiaohui Sun Haidong Kan Yang liu Michelle LBell Rohini Dasan Huiwang gao Xiaohong Yao Yang gao Key laboratory of Marine Environmental Science and Ecology and Frontiers Science Center for Deep Ocean Multispheres and Earth System(Ministry of Education)Ocean University of Chinaand Qingdao National Laboratory for Marine Science and TechnologyQingdao 266100China Department of Emergency Internal Medicine The Affiliated Hospital of Qingdao UniversityQingdao 266100China Division of Environmental Health Sciences School of Public HealthUniversity of CaliforniaBerkeleyBerkeleyCA 94720USA Department of Chronic Disease Prevention Qingdao Municipal Center for Disease Control&PreventionQingdao 266100China School of Public Health Key Laboratory of Public Health Safety of the Ministry of EducationFudan UniversityShanghai 200433China Department of Environmental Health Rollins School of Public HealthEmory UniversityAtlantaGA 30322USA School of the Environment Yale UniversityNew HavenCT 06511USA

Air pollution has been widely associated with adverse effects on the respiratory and cardiovascular *** investigated the relationship between acute myocardial infarction(AMI),chronic obstructive pulmonary disease(COPD)and air pollution exposure in the coastal city of Qingdao,*** pollution in this region is characterized by inland and oceanic transportation sources in addition to local *** examined the influence of PM_(2.5),PM_(10),NO_(2),SO_(2),CO and O_(3) concentrations on hospital admissions for AMI and COPD from October 1,2014,to September 30,2018,in Qingdao using a Poisson generalized additive model(GAM).We found that PM_(2.5),PM_(10),NO_(2),SO_(2) and CO exhibited a significant short-term(lag 1 day)association with AMI in the singlepollutant model among older adults(>65 years old)and females,especially during the cold season(October to March).In contrast,only NO2 and SO2 had clear cumulative lag associations with COPD admission for females and those over 65 years old at lag 01 and lag 03,*** the twopollutant model,the exposure-response relationship fitted by the two-pollutant model did not change *** findings indicated that there is an inflection point between the concentration of certain air pollutants and the hospital admissions of AMI and COPD even under the linear assumption,indicative of the benefits of reducing air pollution vary with pollution *** study has important implications for the development of policy for air pollution control in Qingdao and the public health benefits of reducing air pollution levels.

关键词： AMI COPD Air pollution exposure GAM

One-step spraying method to construct superhydrophobic magnesium surface with extraordinary robustness and multi-functions

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Journal of Magnesium and Alloys 2021年第2期9卷 668-675页

作者： Lingjie Li Xia Li Jinlong Chen Lei liu Jinglei Lei Nianbing Li gao liu Fusheng Pan School of Chemistry and Chemical Engineering Chongqing UniversityChongqing400044 PR China School of Chemistry and Chemical Engineering Southwest UniversityChongqing400715 PR China Energy Storage&Distributed Resources Division Lawrence Berkeley National LaboratoryBerkeleyCA 94720 USA School of Materials Science and Engineering Chongqing UniversityChongqing400044 PR China

The robust magnesium surfaces with multi-functions are highly desirable,and the simple and scalable methods to construct such surfaces are urgently ***,we conducted a one-step spraying method to facilely fabricate the robust coating with multi-functions on magnesium *** as-sprayed magnesium alloys surface is superhydrophobic with a static water contact angle(Wca)of 157.0°and a roll-off angle of 6.0°.Such surface has excellent mechanical,chemical and thermal stabilities,even undergoing various physical and chemical damages,including sand impact(10 gmin^(-1),≥20 min),water impact(2 impacts s^(-1),≥180 min),abrasion(1.00 kPa,≥25 cycles),peeling(≥2.15 kPa),high temperature(200°C,≥24 h),strong acidic/salty/basic media(p H=113)and organic-solvent immersion(ethanol and n-hexane,≥24 h),demonstrating brilliant ***,the surface displays multi-functions of corrosion protection,anti-fouling and heat insulation,which will undoubtedly promote the much wider applications of magnesium alloys.

关键词： Magnesium alloy Spraying method Superhydrophobicity Robustness Multi-functions

The influence of compact and ordered carbon coating on solid-state behaviors of silicon during electrochemical processes

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carbon Energy 2020年第1期2卷 143-150页

作者： Shuo Zhou Chen Fang Xiangyun Song gao liu Energy Storage and Distributed Resources Division Lawrence Berkeley National LaboratoryBerkeleyCalifornia

To address the issues of large volume change and low conductivity of silicon(Si)materials,carbon coatings have been widely employed as surface protection agent and conductive medium to encapsulate the Si materials,which can improve the electrochemical performance of Si-based *** has been a strong demand to gain a deeper understanding of the impact of efficient carbon coating over the lithiation and delithiation process of Si ***,we report the first observation of the extended two-phase transformation of carbon-coated Si nanoparticles(Si/C)during electrochemical *** Si/C nanoparticles were prepared by sintering Si nanoparticles with polyvinylidene chloride *** Si/C electrode underwent a two-phase transition during the first 20 cycles at 0.2 C,but started to engage in solid solution reaction when the ordered compact carbon coating began to *** higher current density conditions,the electrode was also found to be involved in solid solution reaction,which,however,was due to the overwhelming demand of kinetic property rather than the breaking of the carbon *** comparison,the Si/C composites prepared with sucrose possessed more disordered and porous carbon structures,and presented solid solution reaction throughout the entire cycling process.

关键词： anode carbon coating electrochemical behavior lithium-ion batteries silicon

Improving hydrogen evolution reaction efficiency through lattice tuning

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Nano Research 2024年第7期17卷 5907-5913页

作者： Zipeng Zhao Haotian liu Wenpei gao Praveen Kolla Wang Xue Zeyan liu Jinghua Guo Sanjeev Mukerjee Xiaoqing Pan Qingying Jia Xiangfeng Duan Yu Huang Department of Materials Science and Engineering University of CaliforniaLos AngelesCalifornia 90095USA Department of Chemical Engineering and Materials Science University of CaliforniaIrvineCalifornia 92697USA Materials Science and Engineering North Carolina State UniversityRaleighNorth Carolina 27695USA Department of Chemistry and Chemical Biology Northeastern UniversityBostonMassachusetts 02115USA Department of Chemistry and Biochemistry University of CaliforniaLos AngelesCalifornia 90095USA Advanced Light Source Lawrence Berkeley National LaboratoryBerkeleyCalifornia 94720USA Department of Chemistry and Biochemistry University of CaliforniaSanta CruzCalifornia 95064USA Department of Physics and Astronomy University of CaliforniaIrvineCalifornia 92697USA california Nanosystems Institute University of CaliforniaLos AngelesCalifornia 90095USA

The intermittent nature of renewable energy sources sets a requirement for efficient energy storage to mitigate the conflict between energy supply and *** is a promising choice for energy storage due to its high energy ***,the conversion of electrical energy to chemical energy stored in hydrogen through water electrolysis suffers from low efficiency,and the electricity cost dominates the total cost of hydrogen ***,we report the study of improving the hydrogen evolution reaction activity of Pt-based catalysts by building a nanoscale surface NiO and Pt interface,further optimizing the performance via tuning the lattice parameter of the core of nanoparticles,which can be achieved by varying the dealloying annealing *** optimized PtCuNi-O/C and PtNi-O/C catalysts are demonstrated to be one of the best catalysts,with a mass activity(MA)of 9.1 and 8.7 mA/μgPt,which is 9.9-fold and 9.5-fold of that of Pt/C,respectively.

关键词： lattice tuning Pt-based catalyst hydrogen evolution reaction electrocatalysis

Lead halide perovskite nanowires stabilized by block copolymers for Langmuir-Blodgett assembly

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Nano Research 2020年第5期13卷 1453-1458页

作者： Hao liu Martin Siron Mengyu gao Dylan Lu Yehonadav Bekenstein Dandan Zhang Letian Dou A.Paul Alivisatos Peidong Yang Department of Chemistry University of CaliforniaBerkeleyCalifornia 94720USA Department of Materials Science and Engineering University of CaliforniaBerkeleyCalifornia 94720USA Materials Science Division Lawrence Berkeley National LaboratoryBerkeleyCalifornia 94720USA Kavli Energy NanoScience Institute BerkeleyCalifornia 94720USA Center for Advanced Low-dimension Materials Donghua UniversityShanghai 201620China Department of Materials Science and Engineering Technion-Israel institute of technologyHaifa 3200003Israe Davidson School of Chemical Engineering Purdue UniversityWest LafayetteIndiana 47907USA

The rapid development of solar cells based on lead halide perovskites(LHPs)has prompted very active research activities in other closely-related *** nanostructures of such materials display superior optoelectronic ***,onedimensional(1D)LHPs nanowires show anisotropic optical properties when they are highly ***,the ionic nature makes them very sensitive to external environment,limiting their large scale practical ***,we introduce an amphiphilic block copolymer,polystyrene-block-poly(4-vinylpyridine)(PS-P4VP),to chemically modify the surface of colloidal CsPbBr3 *** resulting core-shell nanowires show enhanced photoluminescent emission and good colloidal stability against *** advantage of the stability enhancement,we further applied a modified Langmuir-Blodgett technique to assemble monolayers of highly aligned nanowires,and studied their anisotropic optical properties.

关键词： nanowires anisotropic optical properties aligned monolayer lead halide perovskites stability enhancement

Precisely quantifying bulk transition metal valence evolution in conventional battery electrode by inverse partial fluorescence yield

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Journal of Energy Chemistry 2022年第6期31卷 363-368,I0010页

作者： Kehua Dai Weiwei Shao Beibei Zhao Wenjuan Zhang Yan Feng Wenfeng Mao Guo Ai gao liu Jing Mao Wanli Yang College of Chemistry Tianjin Normal UniversityTianjin 300387China Advanced Light Source Lawrence Berkeley National LaboratoryBerkeleyCA 94720United States College of Physics and Materials Science Tianjin Normal UniversityTianjin 300387China Energy Storage and Distributed Resources Division Energy Technologies AreaLawrence Berkeley National LaboratoryBerkeleyCA 94720United States School of Materials Science and Engineering Zhengzhou UniversityZhengzhou 450001HenanChina

Precisely quantifying transition metal(TM) redox in bulk is a key to understand the fundamental of optimizing cathode materials in secondary batteries. At present, the commonly used methods to probe TM redox are hard X-ray absorption spectroscopy(hXAS) and soft X-ray absorption spectroscopy(sXAS).However, they are both facing challenges to precisely quantify the valence states of some transition metals such as Mn. In this paper, Mn-L iPFY(inverse partial fluorescence yield) spectra extracted from Mn-L m RIXS(mapping of resonant inelastic X-ray scattering) is adopted to quantify Mn valence states. Mn-L i PFY spectra has been considered as a bulk-sensitive, non-distorted probe of TM valence ***, the exact precision of this method is still unclear in quantifying practical battery ***, a series of LiMn_(2)O_(4) electrodes with different charge and discharge states are prepared. Based on their electrochemical capacity(generally considered to be very precise), the precision of Mn iPFY in quantifying bulk Mn valence state is confirmed, and the error range is unraveled. Mn-L mRIXS iPFY thus is identified as one of the best methods to quantify the bulk Mn valence state comparing with hXAS and sXAS.

关键词： cathode materials Valence state of transition metals Lithium-ion batteries Mapping of resonant inelastic X-ray scattering Inverse partial fluorescence yield

Oxygen Reduction Reaction catalyzed by carbon-Supported Platinum Few-Atom Clusters:Significant Enhancement by Doping of Atomic Cobalt

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Research 2020年第1期2020卷 1756-1767页

作者： Bingzhang Lu Qiming liu Forrest Nichols Rene Mercado David Morris Ning Li Peng Zhang Peng gao Yuan Ping Shaowei Chen Department of Chemistry and Biochemistry University of California1156 High StreetSanta CruzCalifornia 950564USA Department of Chemistry Dalhousie University6274 Coburg RoadHalifaxNova ScotiaCanada B3H 4R2 International Center for Quantum Materials School of PhysicsPeking UniversityBeijing 100871China Electron Microscopy laboratory School of PhysicsPeking UniversityBeijing 100871China Collaborative Innovation Centre of Quantum Matter Beijing 100871China

Oxygen reduction reaction(ORR)plays an important role in dictating the performance of various electrochemical energy *** platinum nanoparticles have served as the catalysts of choice towards ORR,minimizing the cost of the catalysts by diminishing the platinum nanoparticle size has become a critical route to advancing the technological ***,first-principle calculations show that carbon-supported Pt9 clusters represent the threshold domain size,and the ORR activity can be significantly improved by doping of adjacent cobalt *** is confirmed experimentally,where platinum and cobalt are dispersed in nitrogen-doped carbon nanowires in varied forms,single atoms,few-atom clusters,and nanoparticles,depending on the initial *** sample consisting primarily of Pt_(2~7)clusters doped with atomic Co species exhibits the best mass activity among the series,with a current density of 4:16Amg^(-1)_(Pt)at+0.85V *** that is almost 50 times higher than that of commercial Pt/C.

关键词： platinum Oxygen cobalt