Acta Materialia最新文献_第5页

Design of shape memory alloys with enhanced thermal management properties via adaptively constrained multi-objective optimization 基于自适应约束多目标优化的形状记忆合金热管理性能优化设计

IF 9.3 1区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Acta Materialia

Pub Date : 2026-01-02 DOI: 10.1016/j.actamat.2025.121874

Yuan Tian , Bin Hu , Pengfei Dang , Shuya Dong , Sheng Sun , Dezhen Xue , Turab Lookman , Tongyi Zhang

Shape memory alloys (SMAs) as solid–solid phase change materials are promising candidates for addressing thermal loads in electronic devices. High thermal energy storage (TES) performance and narrow overall transformation range (OTR) are desirable for rapidly mitigating excess heat in devices with confined spaces and narrow operating temperature windows. However, achieving a combination of high TES performance and a narrow OTR remains challenging due to the inherently conflicting nature of properties and the vast compositional design space. To address this, we propose an adaptively constrained multi-objective optimization strategy that evaluate the expected hypervolume gain of candidates within a constrained preferred region. Through visualization on a mathematical function case and comparative experimental exploration on SMAs, this constrained strategy demonstrates significantly enhanced efficiency in guiding the search toward favorable property trade-offs. With the constrained strategy, all 10 synthesized alloys across three experimental iterations exhibit high TES performance and narrow OTR. Especially, alloy Ti_50.2Ni_43.6Cu_5.8Al_0.4 displays a high TES performance of 2690

\times

10

^{6}

J

^{2}

K⁻¹ s⁻¹ m⁻⁴, which is over 6 times higher than commercial organic PCMs, and 2

\sim

3 times larger than the best-performing TiNiCu (B2–B19) alloys reported in the literature for electronic thermal management. Its narrow OTR (26.81 °C) lies well within the acceptable operating temperature range of electronics. Moreover, it demonstrates good thermal stability after rolling, with a slight shift of 0.18 K in transformation temperature and a decay of only 0.15 J/g in latent heat after 40 cycles.

形状记忆合金（sma）作为固-固相变材料是解决电子器件热负荷的有希望的候选者。高热能储存（TES）性能和窄的整体转换范围（OTR）对于在密闭空间和窄工作温度窗口的设备中快速减轻多余热量是理想的。然而，由于性能的内在冲突性质和巨大的组合设计空间，实现高TES性能和窄OTR的结合仍然具有挑战性。为了解决这个问题，我们提出了一种自适应约束的多目标优化策略，该策略在受限的首选区域内评估候选候选的预期超容量增益。通过对数学函数案例的可视化和对sma的比较实验探索，这种约束策略在指导寻找有利的财产权衡方面显着提高了效率。在受限策略下，经过三次实验迭代，所有10种合成合金均表现出较高的TES性能和较窄的OTR。特别是，Ti50.2Ni43.6Cu5.8Al0.4合金的TES性能为2690 × 106 J2 K−1 s−1 m−4，比商业有机PCMs高6倍以上，比文献中报道的电子热管理性能最好的TiNiCu （B2-B19）合金高2 ~ 3倍。其窄OTR（26.81°C）完全在电子产品可接受的工作温度范围内。轧制后表现出良好的热稳定性，40次循环后，相变温度轻微变化0.18 K，潜热衰减仅为0.15 J/g。

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引用次数: 0

Phase separation engineered high thermoelectric performance in copper sulfides via solid solubility modulation 通过固体溶解度调制在硫化铜中实现高热电性能的相分离工程

IF 9.3 1区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Acta Materialia

Pub Date : 2026-01-02 DOI: 10.1016/j.actamat.2025.121889

Tian-Yu Yang , Jianming Yang , Chao Li , Chong-Yu Wang , Xi Yan , Hao Liang , Jiang-Hu Yu , Yi-Ming Zhang , Fei Wang , Yi-Xin Zhang , Zhen-Hua Ge , Jing Feng , Jiaqing He

The solid solubility of the material usually determines the success of element doping. High-solubility helps to achieve homogeneous doping, and low-solubility is accompanied by the precipitation of the second phase. In this work, FeCoNi alloy and its extended forms was added to the Cu_1.8S matrix, a new insight into the regulation of solid solubility by phase separation was found. Results show that the dopant in the form of alloy is more conducive to phase separation, which corresponding to the experimental phenomenon of reduced solid solubility. Benefiting from the decreased solubility, regular nanoprecipitates were engineered in the matrix, which remarkably reduced thermal conductivity, achieving the lowest value of ∼0.44 Wm⁻¹K⁻¹ at 773 K. Consequently, the ZT reached 1.45 at 773 K, and the average ZT was 0.61 from 323 to 773 K for the sample of Cu_1.8S + 2.5 wt.% FeCoNi. In addition, the mechanical properties and stability have also been improved. Our work demonstrates the new finding that alloying doping is beneficial for decreasing the solubility of dopants and enhancing thermoelectric performance, and this strategy is also expected to apply to the regulation of solubility and performance improvement in other systems.

材料的固溶性通常决定了元素掺杂是否成功。高溶解度有助于实现均匀掺杂，低溶解度伴随着第二相的析出。本研究将FeCoNi合金及其扩展形态添加到Cu1.8S基体中，发现了通过相分离调节固溶性的新见解。结果表明，合金形式的掺杂剂更有利于相分离，这对应于实验中固体溶解度降低的现象。受益于溶解度的降低，在基体中设计了规则的纳米沉淀物，这显著降低了导热性，在773 K时达到了最低值~ 0.44 Wm−1K−1。结果表明，Cu1.8S + 2.5 wt.% FeCoNi样品在773 K时ZT达到1.45，在323 ~ 773 K时平均ZT为0.61。此外，材料的力学性能和稳定性也得到了改善。我们的工作证明了合金掺杂有利于降低掺杂物的溶解度和提高热电性能的新发现，这一策略也有望应用于其他体系的溶解度调节和性能改善。

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引用次数: 0

Deep activating lattice oxygen of NiFeOOH through Zn, W co-modulation for efficient catalyst towards alkaline water oxidization 通过Zn、W共调深度活化NiFeOOH的晶格氧作为高效碱性水氧化催化剂

IF 9.3 1区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Acta Materialia

Pub Date : 2026-01-01 DOI: 10.1016/j.actamat.2025.121893

Hao Zhou , Hua Wang , Yikai Wang , Ranran Li , Heye Fu , Hong Zhao , Cuishuang Jiang , Tingting Yu , Xia Sun , Maoshuai He , Wenxian Wei , Tao Yang

Hydrogen has been widely recognized as one of the most promising energy carriers for addressing the increasingly environmental and energy challenges. Producing hydrogen through water electrolysis is highly sustainable and renewable, but is limited by the sluggish kinetics of the anodic oxygen evolution reaction (OER). We propose a Zn-W co-modulation strategy, which enhances the lattice oxygen chemistry of oxyhydroxides from both thermodynamics and kinetics simultaneously. Particularly, a Zn, W optimized ultrathin NiFeOOH nanosheet catalyst achieves an overpotential of 159 mV at 10 mA cm^-2 and a Tafel slope of 40.02 mV dec^‑1. Density functional theory analysis demonstrates the enhancement mechanism, regarding the existence of unhybridized O_L-2p electrons, the increase of Mot Hubbard U parameter, the upshift of O-2p band and the downshift of lower Hubbard band, the weakening of Ni-O bond and the increase of disordered configuration. Moreover, Gibbs free energy analysis reveals that the OER process on the NiFeOOH catalyst follows Adsorbate Evolution Mechanism (AEM) pathway with Ni sites as the catalytic sites, which shifts to the competition between AEM and Lattice Oxygen Oxidation Mechanism (LOM) on Zn-NiFeOOH, and with Fe sites as AEM catalytic sites, and then shifts to efficient LOM pathway on ZnW-NiFeOOH. This work highlights the importance of enhancing OER efficiency by simultaneously promoting the thermodynamics and kinetics of LOM pathway, and will inspire the work to seek effective strategies based on band engineering.

氢已被广泛认为是解决日益严峻的环境和能源挑战的最有前途的能源载体之一。水电解制氢具有高度的可持续性和可再生性，但受到阳极析氧反应（OER）缓慢动力学的限制。我们提出了一种Zn-W共调制策略，从热力学和动力学两个方面同时增强了氢氧化物的晶格氧化学性质。其中，Zn、W优化的超薄NiFeOOH纳米片催化剂在10 mA cm-2下的过电位为159 mV， Tafel斜率为40.02 mV / dec - 1。密度泛函理论分析表明，未杂化OL-2p电子的存在、Mot Hubbard U参数的增加、O-2p带的上升和下Hubbard带的下降、Ni-O键的减弱和无序构型的增加是增强的机制。Gibbs自由能分析表明，NiFeOOH催化剂上的OER过程遵循以Ni位点为催化位点的吸附演化机制（AEM）途径，由Zn-NiFeOOH上的AEM与晶格氧氧化机制（LOM）、Fe位点为AEM催化位点之间的竞争转变为ZnW-NiFeOOH上的高效LOM途径。这项工作强调了同时促进LOM途径的热力学和动力学来提高OER效率的重要性，并将启发人们寻求基于能带工程的有效策略。

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引用次数: 0

Effect of grain boundary types on He bubble evolution in Ni-based alloys: Experiment and molecular dynamics simulation 晶界类型对ni基合金He气泡演化的影响：实验与分子动力学模拟

IF 9.3 1区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Acta Materialia

Pub Date : 2026-01-01 DOI: 10.1016/j.actamat.2025.121894

Ruichen Duan , Zhenbo Zhu , Ping Yu , Juan Ding , Hefei Huang

Accumulation of He bubbles at grain boundaries (GBs) during operation of Ni-based alloys in molten salt reactors (MSRs) directly induces GB embrittlement, which is the primary cause of mechanical degradation. This study combines high-temperature He ion irradiation experiments and molecular dynamics (MD) simulations to systematically investigate He bubble distribution across various GBs. TEM characterization reveals that increasing GB energy correlates with decreased bubble size but increased number density, He concentration, and swelling. MD simulations of twelve EBSD-selected GBs confirm these trends and demonstrate that He atom evolution kinetics govern bubble characteristics. By quantifying He-GB binding energies and He diffusion behavior, their combined effect on bubble characteristics is revealed: with increasing GB energy, higher He-GB binding energy drives greater He accumulation. Coupled with this accumulation, the slower diffusion characteristic of high-energy GBs restricts He mobility, promoting a higher number density and smaller bubble sizes. Further analysis of atomic density, activation energies, and diffusion coefficients elucidates the fundamental relationships between GB energy, binding energy, and diffusion rates. These findings and quantitative relationships provide a theoretical basis for optimizing GB selection and designing irradiation-resistant Ni-based alloys for advanced reactor applications.

ni基合金在熔盐堆中运行过程中晶界处He气泡的积累直接导致晶界脆化，这是ni基合金力学退化的主要原因。本研究结合高温He离子辐照实验和分子动力学（MD）模拟，系统地研究了He气泡在不同gb中的分布。透射电镜表征表明，随着GB能量的增加，气泡尺寸减小，但气泡密度、He浓度和膨胀率增加。12个ebsd选择的gb的MD模拟证实了这些趋势，并证明了He原子演化动力学控制气泡特性。通过量化He-GB结合能和He扩散行为，揭示了二者对气泡特性的共同影响：随着GB能量的增加，He-GB结合能越高，He积累越大。再加上这种积累，高能gb的缓慢扩散特性限制了He迁移率，促进了更高的数密度和更小的气泡尺寸。进一步分析原子密度、活化能和扩散系数阐明了GB能、结合能和扩散速率之间的基本关系。这些发现和定量关系为优化GB选择和设计用于先进反应堆的耐辐照镍基合金提供了理论依据。

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引用次数: 0

Coupled sulfur vacancies enhance oxygen evolution reaction in monolayer FeNiP2S6-x 偶联硫空位增强了单层FeNiP2S6-x的析氧反应

IF 9.3 1区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Acta Materialia

Pub Date : 2026-01-01 DOI: 10.1016/j.actamat.2025.121892

Ka Wang , Qirui Wei , Ruilin Guan , Zhigang Zhang , Jiawei Zhang , Hengdong Ren , Wenqing Wei , Yuxiang Yan , Haizeng Song , Jingyi Han , Peng Zhan , Xianghong Niu , Shancheng Yan , Xinglong Wu

High-efficiency and low-cost oxygen evolution reaction (OER) catalysts are essential for advancing water electrolysis technologies. Transition metal thiophosphates (TMPSs) have garnered considerable interest in the OER field due to their ability to modulate the electronic states of active atoms through surface defect engineering. In this study, monolayer theoretical calculations reveal that the interaction between adjacent single-double sulfur vacancies (S-DSVs) significantly alters the electronic structure of phosphorus atoms, thereby tuning the binding strength with reaction intermediates and effectively lowering the energy barrier of the rate-determining step. As a result, S-DSVs outperform isolated single sulfur vacancies (SSVs) and double sulfur vacancies (DSVs). Single-layer FeNiP₂S_6-x (SL-FeNiP₂S_6-x) catalysts with uniformly distributed S-DSVs were successfully synthesized via a mild and selective etching process using B(OH)₃. Electrochemical measurements demonstrate that SL-FeNiP₂S_6-x with an optimized S-DSV concentration delivers excellent OER performance, achieving a low overpotential of 171 mV at 10 mA cm^-2 and a Tafel slope of 38 mV dec^‑1 in 1 M KOH—surpassing most reported iron/nickel-based OER catalysts. This work introduces a novel strategy for enhancing electrocatalytic activity by precisely controlling the position and distribution of sulfur vacancies through controllable etching.

高效、低成本的析氧反应催化剂是发展水电解技术的必要条件。过渡金属硫代磷酸盐（tmps）由于其通过表面缺陷工程调节活性原子电子态的能力，在OER领域获得了相当大的兴趣。在本研究中，单层理论计算表明，相邻的单-双硫空位（s - dsv）之间的相互作用显著改变了磷原子的电子结构，从而调节了与反应中间体的结合强度，有效地降低了速率决定步骤的能垒。因此，s - dsv的性能优于孤立的单硫空位（ssv）和双硫空位（dsv）。采用B(OH)3温和选择性蚀刻工艺成功合成了s - dsv分布均匀的单层FeNiP2S6-x （SL-FeNiP2S6-x）催化剂。电化学测量表明，优化S-DSV浓度的SL-FeNiP2S6-x具有出色的OER性能，在10 mA cm-2下实现了171 mV的低过电位，在1 M koh下的Tafel斜率为38 mV dec - 1，超过了大多数报道的铁/镍基OER催化剂。本文介绍了一种通过可控蚀刻精确控制硫空位的位置和分布来提高电催化活性的新策略。

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引用次数: 0

A graph-based approach for tracking grains in time-resolved 2D/3D microstructural datasets 一种基于图的时间分辨二维/三维显微结构数据集颗粒跟踪方法

IF 9.3 1区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Acta Materialia

Pub Date : 2025-12-31 DOI: 10.1016/j.actamat.2025.121885

V.S. Venkatesh , Z. Croft , K. Thornton , A.J. Shahani

Understanding how grains evolve in polycrystalline materials is critical for linking processing to structure and ultimately properties. However, grain tracking in time-resolved 2D/3D datasets remains a major bottleneck due to topological changes, grain translation, sample deformation, and registration errors. Here, we present two new registration-independent tracking algorithms designed to overcome these challenges: a coordinate-transformation-based method based on local misorientation neighborhoods, and a graph-based method that reformulates the microstructure as a network of grains (nodes) and grain boundaries (edges) and uses graph matching to resolve correspondences while preserving topological consistency. We benchmark both against two conventional approaches, volume overlap and centroid-proximity-based matching, using two large-scale 3D phase-field simulations (with and without a thermal gradient) and an experimental laboratory-based x-ray diffraction contrast tomography dataset containing over 2,200 grains. Across all datasets, the graph-based approach consistently achieves the highest tracking efficiency and accuracy, especially in cases with substantial microstructural evolution or sample deformation. We further demonstrate how graph-based representations facilitate the quantification of topological events and guide experimental design by estimating the maximum interval between scans for reliable tracking. These results establish a robust, scalable, and topology-aware framework for 4D materials characterization, with broad applicability to both synthetic and experimental studies.

了解多晶材料中的晶粒如何演化，对于将加工与结构和最终性能联系起来至关重要。然而，由于拓扑变化、颗粒平移、样本变形和配准误差，时间分辨2D/3D数据集中的颗粒跟踪仍然是一个主要瓶颈。在这里，我们提出了两种新的不依赖于配准的跟踪算法，旨在克服这些挑战：一种基于坐标变换的基于局部定向错误邻域的方法，以及一种基于图的方法，该方法将微观结构重新表述为颗粒（节点）和晶界（边缘）的网络，并使用图匹配来解决对应关系，同时保持拓扑一致性。我们对两种传统方法进行基准测试，体积重叠和基于质心邻近度的匹配，使用两个大规模3D相场模拟（有和没有热梯度）和一个实验实验室的x射线衍射对比断层扫描数据集，其中包含2200多个颗粒。在所有数据集中，基于图的方法始终达到最高的跟踪效率和准确性，特别是在具有大量微观结构演变或样品变形的情况下。我们进一步展示了基于图的表示如何促进拓扑事件的量化，并通过估计扫描之间的最大间隔来指导实验设计，以实现可靠的跟踪。这些结果为4D材料表征建立了一个强大的、可扩展的、拓扑感知的框架，广泛适用于合成和实验研究。

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引用次数: 0

Spectral sampling of boron diffusion in Ni alloys: Cr and Mo effects on bulk and grain boundary transport Ni合金中硼扩散的光谱取样：Cr和Mo对体输运和晶界输运的影响

IF 9.3 1区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Acta Materialia

Pub Date : 2025-12-31 DOI: 10.1016/j.actamat.2025.121841

Tyler D. Doležal , Rodrigo Freitas , Ju Li

Understanding how light interstitials migrate in chemically complex alloys is essential for predicting defect dynamics and long-term stability. Here, we introduce a spectral sampling framework to quantify boron diffusion activation energies in Ni and demonstrate how substitutional solutes (Cr, Mo) reshape interstitial point defect transport in both the bulk and along crystallographic defects. In the bulk, boron migration energy distributions exhibit distinct modality tied to solute identity and spatial arrangement: both Cr and Mo raise barriers in symmetric cages but induce directional asymmetry in partially decorated environments. Extending this framework to a

Σ 5 〈 100 〉 210

symmetric tilt grain boundary reveals solute-specific confinement effects. Cr preserves low-barrier in-plane mobility while suppressing out-of-plane transport, guiding boron into favorable midplane voids. Mo, by contrast, imposes an across-the-board reduction in boron mobility, suppressing average diffusivity by two additional orders of magnitude at 800 °C and reducing out-of-plane transport by five orders of magnitude relative to Cr. Both elements promote segregation by producing negative segregation energies, but their roles diverge: Cr facilitates rapid redistribution and stabilization at interfacial sites, consistent with Cr-rich boride formation, while Mo creates deeper and more uniform segregation wells that strongly anchor boron. Together, these complementary behaviors explain the experimental prevalence of Cr- and Mo-rich borides at grain boundaries and carbide interfaces in Ni-based superalloys. More broadly, we establish spectral sampling as a transferable framework for interpreting diffusion in disordered alloys and for designing dopant strategies that control transport across complex interfaces.

了解化学复杂合金中的轻间隙如何迁移对于预测缺陷动力学和长期稳定性至关重要。在这里，我们引入了一个光谱采样框架来量化Ni中的硼扩散活化能，并展示了取代溶质（Cr, Mo）如何重塑体中和沿晶体缺陷的间隙点缺陷输运。在整体中，硼的迁移能分布表现出与溶质同一性和空间排列相关的独特模式：Cr和Mo在对称笼中都会增加屏障，但在部分修饰的环境中会导致方向不对称。将该框架扩展到Σ5 < 100 > 210的对称倾斜晶界，揭示了溶质特异性约束效应。Cr保持低势垒面内迁移，同时抑制面外迁移，引导硼进入有利的中间空隙。相比之下，Mo会全面降低硼的迁移率，在800℃时将平均扩散率降低两个数量级，相对于Cr，将面外输运降低五个数量级。这两种元素都通过产生负的偏析能来促进偏析，但它们的作用不同：Cr有助于界面位置的快速再分配和稳定，与富Cr硼化物形成一致，而Mo则形成更深更均匀的隔离井，牢固地锚定硼。总之，这些互补行为解释了ni基高温合金中富Cr和富mo硼化物在晶界和碳化物界面的实验流行。更广泛地说，我们建立了光谱采样作为一个可转移的框架，用于解释无序合金中的扩散和设计控制复杂界面传输的掺杂剂策略。

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引用次数: 0

Segregation of hydrogen on screw dislocations in tungsten and its impact on dislocation mobility 氢对钨螺位错的偏析及其对位错迁移率的影响

IF 9.3 1区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Acta Materialia

Pub Date : 2025-12-31 DOI: 10.1016/j.actamat.2025.121869

Thomas Leveau, Lisa Ventelon, Mihai-Cosmin Marinica, Emmanuel Clouet

We investigate the interaction between hydrogen atoms and

\frac{1}{2} 〈 111 〉

screw dislocations in tungsten combining density functional theory (DFT) calculations and molecular dynamics (MD) simulations using a newly developed machine learning (ML) potential trained on ab initio data. Our study reveals two distinct hydrogen-decorated dislocation core structures: the previously known hard core configuration and a newly characterized easy core configuration. DFT calculations indicate comparable dislocation-hydrogen interaction energies for both cores, suggesting a potential competition between these configurations. Ising models, parameterized on DFT data are employed to predict hydrogen segregation profiles for both core configurations, and the results are corroborated by MD simulations. Free energy analyses and finite-temperature MD simulations indicate that the hydrogen-decorated hard core is thermodynamically favored over a wide range of temperatures and hydrogen concentrations. The mobility of this stable hydrogen-decorated hard core structure is assessed by evaluating energy barriers through DFT calculations and performing MD simulations under applied stress. Both approaches consistently show that hydrogen segregation on the hard core structure significantly reduces dislocation mobility, leading to a locking of screw dislocations.

我们结合密度泛函理论（DFT）计算和分子动力学（MD）模拟研究了氢原子与钨中12 < 111 >螺位错之间的相互作用，使用了一种基于从头算数据训练的新开发的机器学习（ML）势。我们的研究揭示了两种不同的氢修饰位错核结构：先前已知的硬核结构和新发现的易核结构。DFT计算表明，两个核的位错-氢相互作用能相当，表明这两种构型之间存在潜在的竞争。利用DFT数据参数化的Ising模型预测了两种岩心构型的氢偏析分布，结果得到了MD模拟的证实。自由能分析和有限温度MD模拟表明，氢装饰硬核在广泛的温度和氢浓度范围内具有热力学优势。这种稳定的氢装饰硬核结构的迁移率是通过DFT计算来评估能量势垒和在施加应力下进行MD模拟来评估的。两种方法一致表明，硬核结构上的氢偏析显著降低了位错的迁移率，导致螺旋位错锁定。

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引用次数: 0

Understanding the chlorine adsorption mechanism on carbon surfaces for Li-Cl battery cathodes 锂离子电池阴极碳表面氯吸附机理的研究

IF 9.3 1区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Acta Materialia

Pub Date : 2025-12-30 DOI: 10.1016/j.actamat.2025.121887

Suyeon Baek, Soong-Keun Hyun, Yongseon Kim

With growing interest in Li–Cl batteries as a next-generation energy storage system, an efficient method for storing Cl at the cathode is required. To elucidate the primary mechanisms of Cl adsorption on carbon surfaces and to propose effective electrode design strategies, a theoretical investigation based on atomistic simulations has been performed. The Cl adsorption is found to be governed by the amount of free Cl generated upon delithiation, the number of surface carbon atoms with dangling bonds that act as adsorption sites, and a minimum separation between adsorbed Cl atoms, which is determined in this study to be ∼2.8 Å. Physicochemical analysis indicates that this separation originates from electrostatic repulsion between adsorbates, arising from the slight ionic character of the predominantly covalent Cl–C bond, thereby placing the observed distance between the covalent and ionic diameters of Cl. This required minimum distance is identified as the key factor that ultimately determines the Cl adsorption density and the specific capacity of the carbon cathode. Based on this finding, an outlook on cathode energy density is presented, indicating that a carbon specific surface area exceeding 760 m²/g for a Li/Cl system and 1500 m²/g for a Li/SOCl₂ system is necessary for competitiveness. While this assumes efficient utilization of the adsorbent surface, the high migration energy barrier of adsorbed Cl (∼1.4 eV) suggests that enabling smooth transport of Cl prior to adsorption is also a critical design consideration.

随着人们对锂离子电池作为下一代储能系统的兴趣日益浓厚，需要一种有效的阴极存储锂离子的方法。为了阐明Cl在碳表面吸附的主要机理并提出有效的电极设计策略，进行了基于原子模拟的理论研究。Cl的吸附被发现是由降解时产生的游离Cl的数量、作为吸附位点的悬空键的表面碳原子的数量和吸附Cl原子之间的最小分离决定的，在本研究中确定为~ 2.8 Å。物理化学分析表明，这种分离源于吸附物之间的静电斥力，这是由主要共价Cl - c键的轻微离子特性引起的，从而使所观察到的Cl的共价直径和离子直径之间的距离。这个所需的最小距离被认为是最终决定Cl吸附密度和碳阴极比容量的关键因素。基于这一发现，对阴极能量密度进行了展望，表明锂/Cl体系的碳比表面积超过760 m²/g，锂/SOCl₂体系的碳比表面积超过1500 m²/g是竞争力所必需的。虽然这假设了吸附剂表面的有效利用，但吸附Cl的高迁移能垒（~ 1.4 eV）表明，在吸附之前使Cl顺利迁移也是一个关键的设计考虑因素。

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引用次数: 0

Effects of twinning configurations on the mechanical performance of small-scale FCC metallic materials 孪晶结构对小型FCC金属材料力学性能的影响

IF 9.3 1区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Acta Materialia

Pub Date : 2025-12-30 DOI: 10.1016/j.actamat.2025.121880

Jinqiao Liu , Ranming Niu , Ji Gu , Ying Liu , Song Ni , Julie Cairney , Min Song , Yiu-Wing Mai , Ting Zhu , Xiaozhou Liao

The increasing demand for high-performance miniaturised devices has sparked extensive interest in enhancing the mechanical properties of micro- and nano-sized materials. Deformation twinning, a fundamental mechanism known for enabling strength–ductility synergy in bulk materials, has emerged as a potential strengthening strategy for small-scale systems. However, the relationship between twinning behaviour and the mechanical performance of small-sized materials remains poorly understood. This study employs quantitative in-situ tensile straining transmission electron microscopy combined with comprehensive microstructural characterisation to investigate the effects of three critical aspects of twinning behaviour on mechanical performance in small-sized face-centred cubic metallic materials: twin density, twin–twin interactions, and modes of twin boundary motion. The findings reveal that: (1) increasing twin density improves ductility of small-sized samples, but this effect hinges on the absence of stress-concentration sites; (2) twin–twin interactions, caused by their intersecting behaviour, induce stress concentration and promote necking, resulting in a distinct fracture mechanism compared to single-system twinning; and (3) twin-boundary sliding, in contrast to twin-boundary migration, leads to highly localised deformation, pronounced softening, and significantly reduced ductility. These results provide important insights into the structural design of small-sized single-crystalline materials where twinning-induced plasticity is a dominant deformation mechanism.

对高性能小型化器件的需求日益增长，引发了人们对提高微纳米材料机械性能的广泛兴趣。变形孪晶是一种基本的机制，可以在大块材料中实现强度-延性协同作用，已成为小型系统的潜在强化策略。然而，孪生行为和小尺寸材料的机械性能之间的关系仍然知之甚少。本研究采用原位定量拉伸应变透射电子显微镜结合综合微观结构表征，研究了小尺寸面心立方金属材料孪晶行为的三个关键方面对力学性能的影响：孪晶密度、孪晶相互作用和孪晶边界运动模式。结果表明：(1)增大孪晶密度可提高小尺寸试样的塑性，但这种效果取决于应力集中部位的缺失；(2)与单体系孪晶相比，孪晶相互作用导致应力集中和颈缩，导致断裂机制明显不同；(3)与双界迁移相比，双界滑动会导致高度局部化的变形、明显的软化和显著的延性降低。这些结果为小尺寸单晶材料的结构设计提供了重要的见解，其中孪晶诱导塑性是主要的变形机制。

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