ERI: Interphase Evolution and Electrochemical Behavior for Highly Reversible Zinc Metal Anodes

尽管锂离子电池已广泛应用于从电动汽车到可再生电力电网存储的广泛应用，但锂和过渡金属（如钴）资源的高成本和国内供应有限，使得开发水性可充电锌金属电池作为“超越锂”的补充技术成为必要。然而，在锌金属阳极和电解质之间的区域会发生意想不到的反应，从而影响含水锌电池的寿命和耐用性。为了提高电池寿命，在设计阶段就必须了解阳极与电极之间的面积、相间区域以及锌金属阳极的电化学性能之间的关系。在这个工程研究启动（ERI）项目中，PI和他的研究小组将研究这种间期的演变及其在电池运行过程中对锌阳极性能的影响。该项目将为开发先进的水电池提供关键的科学知识，以保持和推进美国电池技术的领先地位。这个多学科研究项目将为高中生、本科生、硕士和博士学生提供充足的教育和推广机会，包括那些来自STEM领域代表性不足群体的学生。该ERI研究项目旨在推进由SEI缺陷和电子可接近厚度驱动的水固体电解质界面（SEI）演变的基础知识。基于吡唑基含水电解质的实验和建模方法的紧密结合将用于研究影响SEI形成的关键因素，并确认SEI缺陷和厚度的影响。该研究项目的其他独特元素包括：1)利用表面表征确定锌阳极SEI的形态和化学成分作为水溶液pH值、温度和电池循环时间的函数；2)利用电化学阻抗谱和密度泛函理论（DFT）计算，以及SEI的形态和化学信息，确定Zn2+阳离子通过SEI传输的机制。3)利用扫描电镜、纳米压痕和电化学-机械耦合多物理场建模框架，确定了锌金属枝晶的形成/生长和SEI的机械降解对循环历史的依赖关系；4)利用DFT计算结合前三项任务中获得的SEI的电化学-机械信息，确定了水相SEI形成/演化的有利反应途径。通过这个项目，PI将促进新的研究伙伴关系（包括内部和外部合作者），并扩展研究小组在理论建模和高级表征方面的能力。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Although lithium-ion batteries have been widely used for a wide range of applications ranging from electric vehicles to grid storage of renewable electricity, the high cost and limited domestic supply of lithium and transition metal (e.g. cobalt) resources necessitate the development of aqueous rechargeable zinc metal batteries as a “beyond-lithium” complementary technology. However, unwanted reactions occur on the region between zinc metal anode and electrolytes, which compromises the lifetime and durability of aqueous zinc batteries. To improve the cell lifetime, it is important to understand the relationship between the area between the anode and the electrode, the interphase region, and the electrochemical performance of zinc metal anode prior to the design stages. In this Engineering Research Initiation (ERI) project, the PI and his research group will study the evolution of this interphase and its effect on the zinc anode performance during cell operation. The project will provide critical scientific knowledge to develop advanced aqueous batteries for maintaining and advancing US battery technology leadership. The multidisciplinary research project will provide ample educational and outreach opportunities for high school, undergraduate, M.S. and Ph.D. students, including those from underrepresented groups in STEM.This ERI research project seeks to advance fundamental knowledge of the aqueous solid electrolyte interphase (SEI) evolution driven by SEI defects and an electron approachable thickness. A close integration of experimental and modeling approaches based on pyrazole-based containing aqueous electrolytes will be used to study key factors that impact SEI formation and to confirm the effect of the SEI’s defects and thickness. Other unique elements of the research project include 1) identifying the morphology and chemical compositions of zinc anode SEI as a function of aqueous pH value, temperature and cell cycling time using surface characterizations, 2) determining the mechanism of Zn2+ cation transport through the SEI using electrochemical impedance spectroscopy and density functional theory (DFT) calculations in addition to SEI morphology and chemical information, 3) identifying the dependence of zinc metallic dendrite formation/growth and mechanical degradation of the SEI on the cycling history using scanning electron microscopy, nanoindentation and a coupled electrochemical-mechanical multiphysics modeling framework, and 4) identifying the favorable reaction pathways of aqueous SEI formation/evolution using DFT calculations combined with the electro−chemo−mechanical information of the SEI obtained in the first three tasks. Through this project, the PI will catalyze new research partnerships (both with internal and external collaborators) and extend the research group’s capabilities in both theoretical modeling and advanced characterization.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.