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Ahammed B, Ertekin E. Configurational Disorder, Strong Anharmonicity, and Coupled Host Dynamics Lead to Superionic Transport in Li 3YCl 6 (LYC). ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2310537. [PMID: 38279784 DOI: 10.1002/adma.202310537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 12/30/2023] [Indexed: 01/28/2024]
Abstract
In superionic crystals, liquid-like ionic diffusivities often come hand-in-hand with ultra-low thermal conductivity and soft vibrational dynamics. However, generalized relationships between ion transport and vibrational dynamics remain elusive due to the diversity of superionic materials and complex underlying mechanisms. Here, the links between vibrational dynamics and ion transport in close-packed lithium halide ion conductor Li3YCl6 (LYC) are examined using a suite of atomistic first-principles methods. It is shown that configurational disorder, lattice anharmonicity, and coupled host-mobile ion vibrational dynamics together induce a transition to the superionic state. Statistical correlations between ionic hops and activation of the distribution of vibrational modes are found. However, typical phenomena associated with superionic conductors such as selective breakdown of zone-boundary soft phonons, or long wavelength transverse acoustic modes as in the 'phonon-liquid-electron crystal' concept, are not present. Instead, anharmonic zone-boundary modes aiding Li diffusion are found to broaden and soften selectively but persist across the superionic transition. These anharmonic modes couple Li ion motion with the vibrations of the flexible close-packed anion framework, which remains stable and facilitates ionic hopping. The results provide insights into how configurational disorder and soft-yet-resilient vibrational modes enable ionic hopping, particularly in 3D close-packed crystals.
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Affiliation(s)
- Ballal Ahammed
- Department of Mechanical Science & Engineering, University of Illinois at Urbana-Champaign, Illinois, 61801, USA
| | - Elif Ertekin
- Department of Mechanical Science & Engineering, University of Illinois at Urbana-Champaign, Illinois, 61801, USA
- Materials Research Laboratory, University of Illinois at Urbana-Champaign, Illinois, 61801, USA
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Ren G, Che J, Zhang H, Yu Y, Hao W, Shi Y, Yang F, Zhao X. Glass-like thermal conductivity and phonon transport mechanism in disordered crystals. MATERIALS HORIZONS 2024; 11:1567-1578. [PMID: 38265092 DOI: 10.1039/d3mh01681a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2024]
Abstract
Solid materials with ultra-low thermal conductivity (κ) are of great interest in thermoelectrics for energy conversion or as thermal barrier coatings for thermal insulation. Many low-κ materials exhibit unique properties, such as weak or even insignificant dependence on temperature (T) for κ, i.e., an anomalous glass-like behavior. However, a comprehensive theoretical model elucidating the microscopic phonon mechanism responsible for the glass-like κ-T relationship is still absent. Herein, we take rare-earth tantalates (RE3TaO7) as examples to reexamine phonon thermal transport in defective crystals. By combining experimental studies and atomistic simulations up to 1800 K, we revealed that diffusion-like phonons related to inhomogeneous interatomic bonding contribute more than 70% to the total κ, overturning the conventional understanding that low-frequency phonons dominate heat transport. Furthermore, due to the bridging effects of interatomic bonding, the κ of high-entropy tantalates is not necessarily lower than that of medium-entropy materials, suggesting that attempts to reduce κ through high-entropy engineering are limited, at least in defective fluorite tantalates. The new physical mechanism of multimodal phonon thermal transport in defective structures demonstrated in this work provides a reference for the analysis of phonon transport and offers a new strategy to develop and design low-κ materials by regulating the inhomogeneity of interatomic bonding.
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Affiliation(s)
- Guoliang Ren
- Shanghai Key Laboratory of High Temperature Materials and Precision Forming, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.
| | - Junwei Che
- School of Science, Xi'an University of Science and Technology, Xi'an, 710054, China
| | - Hanchao Zhang
- School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.
| | - Yali Yu
- State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China
| | - Wei Hao
- College of Engineering, Zhejiang Normal University, Jinhua, 321004, China
| | - Yinchun Shi
- Shanghai Key Laboratory of High Temperature Materials and Precision Forming, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.
| | - Fan Yang
- School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.
| | - Xiaofeng Zhao
- Shanghai Key Laboratory of High Temperature Materials and Precision Forming, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.
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Tong Z, Dumitrică T, Frauenheim T. Intrinsically Low Thermal Conductivity in the Most Lithium-Rich Binary Stannide Crystalline Li 5Sn. J Phys Chem Lett 2023; 14:8139-8144. [PMID: 37669454 DOI: 10.1021/acs.jpclett.3c02314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/07/2023]
Abstract
Using ab initio lattice dynamics and a unified heat transport theory, we compute the lattice thermal conductivity (κL) of Li5Sn, a newly synthesized crystalline material for Li-ion batteries. The weak bonding in the Li-rich environment leads to significant softening of the optical phonon modes, temperature-induced hardening, and strong anharmonicity. This complexity is captured in the particle-like and glass-like components of κL by accounting for the temperature-dependent interatomic force constants acting on the renormalized phonon frequencies and three- and four-phonon scatterings contributing to the phonon lifetime. We predict very low room-temperature κL values of 0.857, 0.599, and 0.961 W/mK for the experimental Cmcm phase and 0.996, 0.908, and 1.385 W/mK for the theoretically predicted Immm phase along the main crystallographic directions. Both phases display complex crystal behavior with glass-like transport exceeding 20% above room-temperature and an unusual κL temperature dependence. Our results can be used to inform system-level thermal models of Li-ion batteries.
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Affiliation(s)
- Zhen Tong
- School of Advanced Energy, Sun Yat-Sen University, Shenzhen 518107, China
| | - Traian Dumitrică
- Department of Mechanical Engineering, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Thomas Frauenheim
- Beijing Computational Science Research Center, Beijing 100193, China
- Bremen Center for Computational Materials Science, University of Bremen, Bremen 28359, Germany
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Gunatilleke WDCB, Ojo OP, Nolas GS. Thermal properties of cubic NaSbS 2: diffusion dominant thermal transport above the Debye temperature. Chem Commun (Camb) 2023; 59:10936-10939. [PMID: 37605517 DOI: 10.1039/d3cc03455k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/23/2023]
Abstract
We elucidate the thermal properties of superionic conductors, which are of intense current interest for solid-state battery applications. The temperature-dependent thermal properties of superionic NaSbS2 were investigated by analyses of appropriate models revealing that a predominant contribution to thermal transport above the Debye temperature is from thermal diffusion.
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Affiliation(s)
| | - Oluwagbemiga P Ojo
- Department of Physics, University of South Florida, Tampa, FL 33620, USA.
| | - George S Nolas
- Department of Physics, University of South Florida, Tampa, FL 33620, USA.
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Du PH, Zhang C, Sun J, Li T, Sun Q. Phase Stability, Strong Four-Phonon Scattering, and Low Lattice Thermal Conductivity in Superatom-Based Superionic Conductor Na 3OBH 4. ACS APPLIED MATERIALS & INTERFACES 2022; 14:47882-47891. [PMID: 36239388 DOI: 10.1021/acsami.2c14435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Superatom-based superionic conductors are of current interest due to their promising applications in solid-state electrolytes for rechargeable batteries. However, much less attention has been paid to their thermal properties, which are vital for safety and performance. Motivated by the recent synthesis of superatom-based superionic conductor Na3OBH4 consisting of superhalogen cluster BH4, we systematically investigate its lattice dynamics and thermal conductivity using the density functional theory combined with a self-consistent phonon approach. We reveal the bonding hierarchy features by studying the electron localization function and potential energy surface and further unveil the rattling effect of the BH4 superatom, which introduces strong quartic anharmonicity and induces soft phonon modes in low temperatures by assisting Na displacements, thus calling for the necessity of quartic renormalization and four-phonon scattering in calculating the lattice thermal conductivity. We find that the contribution of four-phonon processes to the lattice thermal conductivity increases from 13 to 32% when the temperature rises from 200 to 400 K. At room temperature (300 K), the phonon scattering phase space is enlarged by 133% due to the four-phonon interactions, and the lattice thermal conductivity is evaluated to be 5.34 W/mK, reduced by 24% as compared with a value of 6.99 W/mK involving three-phonon scattering only. These findings provide a better understanding of the lattice stability and thermal transport properties of superionic conductor Na3OBH4, shedding light on the role of strong quartic anharmonicity played in superatom-based materials.
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Affiliation(s)
- Peng-Hu Du
- School of Materials Science and Engineering, Peking University, Beijing100871, China
| | - Cunzhi Zhang
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois60637, United States
| | - Jie Sun
- School of Materials Science and Engineering, Peking University, Beijing100871, China
- Center for Applied Physics and Technology, Peking University, Beijing100871, China
| | - Tingwei Li
- School of Materials Science and Engineering, Peking University, Beijing100871, China
| | - Qiang Sun
- School of Materials Science and Engineering, Peking University, Beijing100871, China
- Center for Applied Physics and Technology, Peking University, Beijing100871, China
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