A Multiscale Computational Analysis of Defect-assisted Ionic Transport in Plastically Deformed Solid Oxides

塑性变形固体氧化物中缺陷辅助离子输运的多尺度计算分析

• 批准号: 2322675
• 负责人: Liming Xiong
• 金额: $ 43.33万
• 依托单位: North Carolina State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-01-01 至 2024-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2322675&HistoricalAwards=false
• 关键词: Multiscale; Computational; Analysis; Defect; assisted

Solid oxide fuel cell (SOFC) directly converts fossil fuel into electricity introducing no pollution but water into the environment. This technology has been developing rapidly but is still limited in practical use due to its high operating temperature. Reducing the SOFC operation temperature towards its widespread applications has triggered an intensive search of super ionic conducting solid oxides. Introducing defects, such as dislocations, into certain oxides has been demonstrated to be promising in achieving a considerably high ionic conductivity at low temperature but this technique is still in a "trial and error" stage due to lack of knowledge on how ions hop under the effects of the defect-induced stress field in plastically deformed solid oxides. To meet this need, this award supports fundamental research on computer simulations of ions hopping in defected solid oxides, across a wide range of length scales. The gained knowledge may be utilized in the development of not only low temperature SOFCs, but also lithium/sodium-ion batteries, perovskite solar cells, corrosion-resistant materials for medical implants, and radiation-resistant materials for nuclear power plants. This project is multidisciplinary in nature. The participating students will be exposed to a broad range of scientific knowledge, methodology, and skills. A mentoring program that links the education of graduate, undergraduate, and high-school students will be fostered. The high operation temperature in SOFC stems from the high ion migration barrier (~1eV) in solid oxides. Distinct from traditional approaches that overcome this barrier by exposing the materials to an elevated temperature, this project presents a plan on promoting ionic transport using severe stress localizations in plastically deformed solid oxides. The local stress's contribution to the ion migration barrier reduction will be quantified through a series of concurrent atomistic-continuum (CAC) simulations. Polycrystalline strontium titanate and multilayered strontium titanate /magnesium oxide containing a high density of grain boundaries (GBs) and phase boundaries (PBs) will be chosen as the model materials. The CAC simulations will bridge the relevant length scales through resolving the GBs and PBs at an atomistic resolution while the dislocations away from them will be dealt in a coarse-grained description. This will enable a prediction of the microscopic-level ionic transport in strained solid oxides without smearing out the atomistic nature of ion hopping near the material defects. Data and insights regarding diffusion under stress, which controls the kinetics of phase transformations, oxidation, creep, and many other engineering processes in solid materials, will be generated.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

固体氧化物燃料电池（SOFC）将化石燃料直接转化为电力，而是引入不污染的，而是将水引入环境。这项技术一直在迅速发展，但由于其高工作温度，实际使用仍然受到限制。降低SOFC操作温度向其广泛的应用引发了对超离子导电固体氧化物的深入搜索。已经证明，将缺陷（例如位错）引入某些氧化物，在低温下达到相当高的离子电导率方面有希望，但是由于缺乏对离子如何在缺陷诱导的固体固体氧化物中缺陷诱导的应力场效果下跳跃的知识，因此该技术仍处于“试验和误差”阶段。为了满足这一需求，该奖项支持对较大长度范围内的固体氧化物跳动的计算机模拟的基础研究。获得的知识不仅可以用于低温SOFC的开发，还可以用于开发锂/钠离子电池，钙钛矿太阳能电池，用于医疗植入物的耐腐蚀材料以及核发电厂的耐辐射材料。该项目本质上是多学科的。参与的学生将接触到广泛的科学知识，方法论和技能。将培养一个指导计划，该计划将培养研究生，本科和高中生的教育。 SOFC中的高操作温度源于固体氧化物中的高离子迁移屏障（〜1EV）。该项目与传统的方法通过将材料暴露于升高温度来克服了这一障碍的方法，该项目提出了一项计划，该计划使用塑料变形的固体氧化物中使用严重的应激定位来促进离子运输。当地应力对离子迁移屏障降低的贡献将通过一系列并发的原子 - 胞源（CAC）模拟来量化。多晶硝酸锶和含有高密度晶界（GBS）和相边界（PBS）的多层钛含量 /氧化镁（PBS）将被选为模型材料。 CAC模拟将通过以原子分辨率解​​析GB和PBS来弥合相关的长度尺度，而从它们的脱位则将在粗粒化的描述中处理。这将使在紧张的固体氧化物中的显微镜离子转运进行预测，而不会抹杀材料缺陷附近离子跳的原子性质。将在压力下进行有关扩散的数据和见解，该奖项将在固体材料中控制相变，氧化，蠕变以及许多其他工程过程的动力学。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子和更广泛影响的评估来通过评估来获得支持的。

项目成果

Effect of a micro-scale dislocation pileup on the atomic-scale multi-variant phase transformation and twinning

• DOI: 10.1016/j.commatsci.2023.112508
• 发表时间: 2022-08
• 期刊: Computational Materials Science
• 影响因子: 3.3
• 作者: Yipeng Peng;Rigelesaiyin Ji;T. Phan;L. Capolungo;V. Levitas;Liming Xiong

Effect of a Long-Range Dislocation Pileup on the Atomic-Scale Hydrogen Diffusion near a Grain Boundary in Plastically Deformed bcc Iron

• DOI: 10.3390/cryst13081270
• 发表时间: 2023-08
• 期刊: Crystals
• 影响因子: 2.7
• 作者: Yipeng Peng;Rigelesaiyin Ji;T. Phan;Xiang Chen;Ning Zhang;Shuozhi Xu;A. Bastawros;Liming Xiong-Liming-Xio

Multiscale computational and experimental analysis of slip-GB reactions: In situ high-resolution electron backscattered diffraction and concurrent atomistic-continuum simulations

• DOI: 10.1016/j.scriptamat.2023.115500
• 发表时间: 2023-07
• 期刊: Scripta Materialia
• 影响因子: 6
• 作者: Yang Su;T. Phan;Liming Xiong;J. Kacher