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A first-principles study on stabilizing disordered LiNi0.5Mn1.5O4 cathode material by doping

Journal of Energy Storage 2024年 83卷

作者： Lin, Che-an Lin, Shih-kang Department of Materials Science and Engineering National Cheng Kung University Tainan70101 Taiwan Program on Smart and Sustainable Manufacturing Academy of Innovative Semiconductor and Sustainable Manufacturing National Cheng Kung University Tainan70101 Taiwan Research Center National Cheng Kung University Tainan70101 Taiwan Core Facility Center National Cheng Kung University Tainan70101 Taiwan

High-voltage LiNi0.5Mn1.5O4 (LNMO) is a promising cathode material for high energy-density Li-ion batteries. The LNMO phase exhibits either ordered or disordered structure;meanwhile, the Mn ions possess 3+ and 4+ mixed valence states. The main challenges of LNMO cathode material for real applications are that the ordered LNMO phase possesses poor rate capability and that the Mn3+/4+ redox reaction leads to Mn dissolution. Doping has been a straightforward approach to address these issues, by enhancing the stability of the disordered LNMO phase and reducing the Mn3+ fraction in LNMO. However, experimental trials involved different setups and uncertainties, which usually cannot be directly compared, and thus an investigation of doping influence on disordered LNMO based on fair comparison is required. Herein, we screened and proposed the best dopants that can improve LNMO performance, and we clarified the corresponding mechanism based on first-principles calculations and thermodynamics. The stable doping systems and preferred doping sites were obtained through phase stability evaluation. Mechanism of disordered LNMO stabilization was obtained through analyzing the relation between the change of transition metal valence states after doping and the ability of dopants to stabilize disordered LNMO. It was found that not only extra-electron dopants stabilize disordered LNMO, as most of the studies reported, but extra-hole dopants could also stabilize disordered LNMO. Furthermore, considering the Mn3+/4+ redox reaction, extra-hole dopants, including Mg, Na, and Zn, were suggested to be the dopants that could improve LNMO performance with simultaneously increasing the fraction of disordered phase and avoiding Mn3+/4+ redox reaction. © 2024 Elsevier Ltd

关键词： Thermodynamics

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Evolution of Electronic and Magnetic Properties in Topological Semimetal SmSbxTe2-x

arXiv

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arXiv 2022年

作者： Pandey, Krishna Basnet, Rabindra Wang, Jian Da, Bo Hu, Jin Materials Science and Engineering Program Institute for Nanoscience and Engineering University of Arkansas FayettevilleAR72701 United States Department of Physics University of Arkansas FayettevilleAR72701 United States Department of Chemistry Wichita State University WichitaKS67260 United States Research and Services Division of Materials Data and Integrated System National Institute for Materials Science 1-1 Namiki Ibaraki Tsukuba305-0044 Japan

The ZrSiS-type materials have attracted intensive attention due to the existence of various topological fermions. The magnetic version of the ZrSiS-type materials, LnSbTe (Ln = lanthanides), is an ideal candidate to explore novel exotic states due to the interaction between magnetism and topology. In this work, we report the experimental study on structural, magnetic, thermodynamic, and electronic properties for SmSbxTe2-xwith various Sb content. The revealed evolutions of these properties with tuning the compositions would provide useful insights for the fundamental topological physics and the future applications. © 2022, CC BY.

关键词： Electronic properties

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Tipt: The Tracer Injection Planning Tool

SSRN

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SSRN 2022年

作者： González-Pinzón, Ricardo Dorley, Jancoba Singley, Joel Singha, Kamini Gooseff, Michael Covino, Tim Civil Construction and Environmental Engineering University of New Mexico AlbuquerqueNM United States Department of Geology and Geological Engineering Hydrologic Science and Engineering Program Colorado School of Mines GoldenCO United States Environmental Studies Program University of Colorado BoulderCO United States Institute of Arctic and Alpine Research BoulderCO United States Ecosystem Science and Sustainability Colorado State University Fort CollinsCO United States

We combined the advection-dispersion-reaction equation, peak concentration estimates based on a meta-analysis of hundreds of tracer injections in streams and rivers, and mass balances in a dynamic Excel Workbook to 1) help users decide how much tracer mass should be added to achieve dynamic concentration ranges that reduce known issues associated with breakthrough curve tail truncation, and 2) generate tables and graphs that can be used to plan logistics. Our Tracer Injection Planning Tool, TIPT, handles instantaneous and continuous tracer injections, assumes steady-state and uniform flow conditions, and first-order decay or production. While those assumptions do not strictly apply to natural streams, they simplify the planning of tracer injections with a predictive ability disproportionally favorable with respect to the few inputs required. We demonstrate the use of TIPT through two case studies, i.e., a continuous injection in a 2nd order stream and an instantaneous injection in a 7th order stream. © 2022, The Authors. All rights reserved.

关键词： Solute transport

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Density functional modeling and total scattering analysis of the atomic structure of a quaternary CaO−MgO−Al2O3−SiO2 (CMAS) glass: Uncovering the local environment of calcium and magnesium

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Physical Review materials 2021年第1期5卷 015603-015603页

作者： Kai Gong V. Ongun Özçelik Kengran Yang Claire E. White Department of Civil and Environmental Engineering Andlinger Center for Energy and the Environment Princeton University Princeton New Jersey 08544 USA Department of Chemistry and Biochemistry Materials Science and Engineering Program University of California San Diego La Jolla California 92093 USA

Quaternary CaO−MgO−Al2O3−SiO2 (CMAS) glasses are important constituents of the Earth's lower crust and mantle, and they also have important industrial applications such as in metallurgical processes, concrete production, and emerging low-CO2 cement technologies. In particular, these applications rely heavily on the composition-structure-reactivity relationships for CMAS glasses, which are not yet well established. In this study, we combined force-field molecular dynamics (MD) simulations and density functional theory (DFT) calculations to generate detailed structural representations for a CMAS glass. The generated structures are not only thermodynamically favorable (according to DFT calculations) but also agree with experiments (including our x-ray and neutron total scattering data as well as literature data). Detailed analysis of the final structure (including partial pair distribution functions, coordination number, and oxygen environment) enabled existing discrepancies in the literature to be reconciled and has revealed important structural information on the CMAS glass, specifically (i) the unambiguous assignment of medium-range atomic ordering, (ii) the preferential role of Ca atoms as charge compensators and Mg atoms as network modifiers, (iii) the proximity of Mg atoms to free oxygen sites, and (iv) clustering of Mg atoms. Electronic property calculations suggest higher reactivity for Ca atoms as compared with Mg atoms, and that the reactivity of oxygen atoms varies considerably depending on their local bonding environment. Overall, this information may enhance our mechanistic understanding on CMAS glass dissolution behavior in the future, including dissolution-related mechanisms occurring during the formation of low-CO2 cements.

关键词： Atomic & molecular structure Composition Density functional theory Scattering of atoms, molecules, clusters & ions Structural properties

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Promises and technological prospects of two-dimensional Rashba materials

arXiv

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arXiv 2024年

作者： Bordoloi, Arjyama Garcia-Castro, A.C. Romestan, Zachary Romero, Aldo H. Singh, Sobhit Department of Mechanical Engineering University of Rochester RochesterNY14627 United States School of Physics Universidad Industrial de Santander Carrera 27 Calle 9 Bucaramanga680002 Colombia Department of Physics and Astronomy West Virginia University MorgantownWV26505-6315 United States Materials Science Program University of Rochester RochesterNY14627 United States

The Rashba spin-orbit coupling effect, primarily arising from structural-inversion asymmetry in periodic crystals, has garnered considerable attention due to its tunability and potential applications in spintronics. Its capability to manipulate electron spin without an external magnetic field opens new avenues for spintronic device design, particularly in semiconductor technology. Within this framework, 2D Rashba materials hold special interest due to their inherent characteristics, which facilitate miniaturization and engineering capabilities. In this Perspective article, we provide an overview of recent advancements in the research of 2D Rashba materials, aiming to offer a comprehensive understanding of the diverse manifestations and multifaceted implications of the Rashba effect in material science. Rather than merely presenting a list of materials, our approach involves synthesizing various viewpoints, assessing current trends, and addressing challenges within the field. Our objective is to bridge the gap between fundamental research and practical applications by correlating each material with the necessary advancements required to translate theoretical concepts into tangible technologies. Furthermore, we highlight promising avenues for future research and development, drawing from insights gleaned from the current state of the field. © 2024, CC BY.

关键词： Magnetic moments

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Imaging 3D Chemistry at 1 nm Resolution with Fused Multi-Modal Electron Tomography

arXiv

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arXiv 2023年

作者： Schwartz, Jonathan Di, Zichao Wendy Jiang, Yi Manassa, Jason Pietryga, Jacob Qian, Yiwen Cho, Min Gee Rowell, Jonathan L. Zheng, Huihuo Robinson, Richard D. Gu, Junsi Kirilin, Alexey Rozeveld, Steve Ercius, Peter Fessler, Jeffrey A. Xu, Ting Scott, Mary Hovden, Robert Department of Materials Science and Engineering University of Michigan Ann ArborMI United States Mathematics and Computer Science Division Argonne National Laboratory LemontIL United States Advanced Photon Source Facility Argonne National Laboratory LemontIL United States Department of Material Science and Engineering Northwestern University EvanstonIL United States Department of Materials Science and Engineering University of California at Berkeley BerkeleyCA United States Department of Chemistry and Chemical Biology Cornell University IthacaNY United States Argonne Leadership Computing Facility Argonne National Laboratory LemontIL United States Department of Material Science and Engineering Cornell University IthacaNY United States Kavli Institute at Cornell for Nanoscale Science Cornell University IthacaNY United States Dow Chemical Co. MidlandMI United States National Center for Electron Microscopy Molecular Foundry Lawrence Berkeley National Laboratory BerkeleyCA United States Department of Electrical Engineering and Computer Science University of Michigan Ann ArborMI United States Materials Science Division Lawrence Berkeley National Laboratory BerkeleyCA United States Applied Physics Program University of Michigan Ann ArborMI United States

Measuring the three-dimensional (3D) distribution of chemistry in nanoscale matter is a longstanding challenge for metrological science. The inelastic scattering events required for 3D chemical imaging are too rare, requiring high beam exposure that destroys the specimen before an experiment completes. Even larger doses are required to achieve high resolution. Thus, chemical mapping in 3D has been unachievable except at lower resolution with the most radiation-hard materials. Here, high-resolution 3D chemical imaging is achieved near or below one nanometer resolution in a Au-Fe3O4 metamaterial, Co3O4 - Mn3O4 core-shell nanocrystals, and ZnS-Cu0.64S0.36 nanomaterial using fused multi-modal electron tomography. Multi-modal data fusion enables high-resolution chemical tomography often with 99% less dose by linking information encoded within both elastic (HAADF) and inelastic (EDX / EELS) signals. Now sub-nanometer 3D resolution of chemistry is measurable for a broad class of geometrically and compositionally complex materials. © 2023, CC BY.

关键词： Zinc sulfide

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Magnetic structure and field-induced transitions in the triangular spin-1 antiferromagnet NiNb2O6: Observation of a triple point

引用

Physical Review B 2023年第22期108卷 224430-224430页

作者： Maruthi R Sobhit Singh Sayandeep Ghosh Mohindar S. Seehra Bruno Weise Wilfrid Prellier Subhash Thota Department of Physics Indian Institute of Technology Guwahati Assam 781039 India Department of Physics B.M.S. College of Engineering Bangalore 560019 Karnataka India Department of Mechanical Engineering University of Rochester Rochester New York 14627 USA Materials Science Program University of Rochester Rochester New York 14627 USA Department of Physics Chungnam National University Daejeon 34134 Republic of Korea Department of Physics Kunsan National University Gunsan 54150 Republic of Korea Department of Physics & Astronomy West Virginia University Morgantown West Virginia 26506 USA Leibniz-IFW Dresden Institute for Complex Materials D-01069 Dresden Germany CRISMAT laboratory Normandy University ENSICAEN UNICAEN National Center for Scientific Research 14000 Caen France

A comprehensive experiment-theory study on the magnetic field-induced spin-flip transitions (HC1 and HC2) and the field-temperature (H−T) phase diagram of nickel niobate (NiNb2O6) polycrystals is reported. Magnetic susceptibility (χ) measurements reveal the presence of quasi-one-dimensional magnetism with spin-1 Ni2+ Heisenberg spin chains, instead of Ising chains, along the easy axis (c axis). The ferromagnetic intrachain exchange-interaction strength, J0/kB (=4.20 K), between Ni2+ ions in the c axis is estimated from the molecular-field theory approximation. The interchain exchange interactions J1/kB=−1.335 K and J2/kB=−1.298 K have been determined from the experimentally obtained magnitudes of HC1=10.8 kOe and spin-saturated field HS=38 kOe. These magnitudes are consistent with the total magnetic exchange-interaction strength, J/kB=7.00 K obtained from χ−T data fitted with the Heisenberg linear chain model and our density-functional theory (DFT+U) calculations. The overall antiferromagnetic behavior of the NiNb2O6 system, correctly captured within our DFT+U calculations, occurs below TN=5.59±0.02 K as determined from the analysis of the specific heat (CP−T) data. The CP vs T data near TN is fitted to power-law expression CP=A|T−TN|−α yielding the critical exponent α=0.349(2) [0.349(1)] for T>TN (T

关键词： Magnetic interactions Magnetic phase transitions Magnetism Structural properties

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Shallow and Deep States of Beryllium Acceptor in GaN: Why Photoluminescence Experiments Do Not Reveal Small Polarons for Defects in Semiconductors

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Physical Review Letters 2021年第2期126卷 027401-027401页

作者： D. O. Demchenko M. Vorobiov O. Andrieiev T. H. Myers M. A. Reshchikov Department of Physics Virginia Commonwealth University Richmond Virginia 23220 USA Materials Science Engineering and Commercialization Program Texas State University San Marcos Texas 78666 USA

Currently, only one shallow acceptor (Mg) has been discovered in GaN. Here, using photoluminescence (PL) measurements combined with hybrid density functional theory, we demonstrate that a shallow effective-mass state also exists for the BeGa acceptor. A PL band with a maximum at 3.38 eV reveals a shallow BeGa acceptor level at 113±5 meV above the valence band, which is the lowest value among any dopants in GaN reported to date. Calculations suggest that the BeGa is a dual-nature acceptor with the “bright” shallow state responsible for the 3.38 eV PL band, and the “dark,” strongly localized small polaronic state with a significantly lower hole capture efficiency.

关键词： Defects Electronic structure Doped semiconductors Semiconductor compounds Density functional calculations Photoluminescence

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Surface molecular engineering to enable processing of sulfide solid electrolytes in humid ambient air

arXiv

引用

arXiv 2024年

作者： Liu, Mengchen Hong, Jessica J. Sebti, Elias Zhou, Ke Wang, Shen Feng, Shijie Pennebaker, Tyler Hui, Zeyu Miao, Qiushi Lu, Ershuang Harpak, Nimrod Yu, Sicen Zhou, Jianbin Oh, Jeong Woo Song, Min-Sang Luo, Jian Clément, Raphaële J. Liu, Ping Department of Chemical and Nano Engineering University of California La Jolla San DiegoCA United States Materials Department University of California Santa Barbara Santa BarbaraCA United States Materials Research Laboratory University of California Santa BarbaraCA United States Program of Materials Science University of California La Jolla San DiegoCA United States Department of Chemistry University of California La Jolla San DiegoCA United States LG Energy Solution Ltd. LG Science Park Magokjungang 10-ro Gangseo-gu Seoul07796 Korea Republic of

Sulfide solid-state electrolytes (SSEs) are promising candidates to realize all solid-state batteries (ASSBs) due to their superior ionic conductivity and excellent ductility. However, their hypersensitivity to moisture requires processing environments that are not compatible with today's lithium-ion battery manufacturing infrastructure. Herein, we present a reversible surface modification strategy that enables the processability of sulfide SSEs (e. g., Li6PS5Cl) under humid ambient air. We demonstrate that a long chain alkyl thiol, 1-undecanethiol, is chemically compatible with the electrolyte with negligible impact on its ion conductivity. Importantly, the thiol modification extends the amount of time that the sulfide SSE can be exposed to air with 33% relative humidity (33% RH) with limited degradation of its structure while retaining a conductivity of above 1 mS cm-1 for up to 2 days, a more than 100-fold improvement in protection time over competing approaches. Experimental and computational results reveal that the thiol group anchors to the SSE surface, while the hydrophobic hydrocarbon tail provides protection by repelling water. The modified Li6PS5Cl SSE maintains its function after exposure to ambient humidity when implemented in a Li0.5In||LiNi0.8Co0.1Mn0.1O2 ASSB. The proposed protection strategy based on surface molecular interactions represents a major step forward towards cost-competitive and energy-efficient sulfide SSE manufacturing for ASSB applications. Copyright © 2024, The Authors. All rights reserved.

关键词： Sulfur compounds

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Subdiffusive wave transport and weak localization transition in three-dimensional stealthy hyperuniform disordered systems

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Physical Review B 2022年第6期105卷 064204-064204页

作者： F. Sgrignuoli S. Torquato L. Dal Negro Department of Electrical and Computer Engineering & Photonics Center Boston University 8 Saint Mary's Street Boston Massachusetts 02215 USA Department of Chemistry Department of Physics Princeton Institute for the Science and Technology of Materials and Program in Applied and Computational Mathematics Princeton University Princeton New Jersey 08540 USA Division of Material Science and Engineering Boston University 15 Saint Mary's Street Brookline Massachusetts 02446 USA Department of Physics Boston University 590 Commonwealth Avenue Boston Massachusetts 02215 USA

The purpose of this work is to understand the fundamental connection between structural correlations and light localization in three-dimensional (3D) open scattering systems of finite size. We numerically investigate the transport of vector electromagnetic waves scattered by resonant electric dipoles spatially arranged in 3D space by stealthy hyperuniform disordered point patterns. Three-dimensional stealthy hyperuniform disordered systems are engineered with different structural correlation properties determined by their degree of stealthiness χ. Such fine control of exotic states of amorphous matter enables the systematic design of optical media that interpolate in a tunable fashion between uncorrelated random structures and crystalline materials. By solving the electromagnetic multiple scattering problem using Green's matrix spectral method, we establish a transport phase diagram that demonstrates a distinctive transition from a diffusive to a weak localization regime beyond a critical scattering density that depends on χ. The transition is characterized by studying the Thouless number and the spectral statistics of the scattering resonances. In particular, by tuning the χ parameter, we demonstrate large spectral gaps and suppressed subradiant proximity resonances, facilitating light localization. Moreover, consistently with previous studies, our results show a region of the transport phase diagram where the investigated scattering systems become transparent. Our work provides a systematic description of the transport and weak localization properties of light in stealthy hyperuniform structures and motivates the engineering of photonic systems with enhanced light-matter interactions for applications to both classical and quantum devices.

关键词： Anderson localization Light-matter interaction Mesoscopics Photonics Scattering theory Weak localization Metamaterials

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