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)直接将化石燃料转化为电力，不会对环境造成污染，但会给环境带来水。该技术发展迅速，但由于其工作温度较高，在实际应用中仍受到限制。SOFC运行温度的降低引发了人们对超离子导电固体氧化物的研究。在某些氧化物中引入缺陷，如位错，已被证明在低温下获得相当高的离子导电性是有希望的，但由于缺乏关于离子如何在塑性变形的固体氧化物中的缺陷诱导应力场的影响下跳跃的知识，这项技术仍处于“试错”阶段。为了满足这一需要，该奖项支持在广泛的长度范围内对有缺陷的固体氧化物中的离子跳跃进行计算机模拟的基础研究。所获得的知识不仅可用于低温固体氧化物燃料电池的开发，还可用于锂/钠离子电池、钙钛矿太阳能电池、医用植入物的耐腐蚀材料和核电站的抗辐射材料的开发。这个项目的性质是多学科的。参与的学生将接触到广泛的科学知识、方法和技能。培育研究生、本科生和高中生教育相结合的辅导计划。SOFC运行温度高的原因是固体氧化物中离子迁移势垒较高(~1 eV)。与通过将材料暴露在高温下来克服这一障碍的传统方法不同，该项目提出了一项利用塑性变形固体氧化物中的严重应力局部化来促进离子传输的计划。局域应力对离子迁移势垒降低的贡献将通过一系列并行的原子-连续(CAC)模拟来量化。多晶钛酸锶和具有高密度晶界(GBs)和相界(PBS)的多层钛酸锶/氧化镁将被选为模型材料。CAC模拟将通过在原子分辨率下解析GB和PBS来跨越相关的长度尺度，而远离它们的位错将以粗粒度描述来处理。这将能够预测应变固体氧化物中微观水平的离子传输，而不会掩盖材料缺陷附近离子跳跃的原子性质。将产生有关应力下扩散的数据和见解，该扩散控制固体材料中相变、氧化、蠕变和许多其他工程过程的动力学。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

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