SUBJECT: Ph.D. Proposal Presentation
BY: Sang Yun Han
TIME: Tuesday, February 4, 2020, 9:30 a.m.
PLACE: Love Building, 109
TITLE: Creating Structured Materials Using Alkali Metals as a Processing Agent and Their Application in Energy Storage Systems
COMMITTEE: Dr. Matthew McDowell, Chair (ME/MSE)
Dr. Michael Filler (ChBE)
Dr. Hailong Chen (ME)
Dr. Seung Woo Lee (ME)
Dr. Ting Zhu (ME)


The aim of this project is to develop processing routes using alkali metals to create microstructured materials, and to understand the properties of these materials in electrochemical energy storage systems. Structures such as nanowires and porous materials have inherent advantages that arise from their structure. Advantages of nanowires include their optical, electrical and mechanical properties deriving from their one-dimensional geometry, high surface area, controllable chemistry, and mechanical flexibility. Porous structures can have enhanced mechanical properties (e.g., improved yield strength, high specific surface area, and low density) as well as multifunctionality (e.g., radiation shielding or thermal insulation) when used in various applications. This project will investigate the use of Li, a common alkali metal, as a processing agent to create advanced material structures. Li is highly reactive and can form alloys with various materials at relatively low temperature (<300 °C), and it can easily be removed from Li alloys (electro)chemically. We find that conditions can be controlled during chemical alloying and dealloying to fabricate different structures such as nanowires or bicontinuous porous metals. For the remainder of the thesis, I will investigate how created structures perform in batteries by correlating electrochemical performance with stress evolution. Full battery cells utilizing structured materials will be investigated to determine electrochemical behavior. This work will advance our understanding of new methods to fabricate structured metals, and how these materials behave in next-generation energy storage systems.