Electronic Thesis and Dissertation Repository


Master of Engineering Science


Mechanical and Materials Engineering


Dr. Xueliang (Andy) Sun


With climate change occurring because of greenhouse gas emissions, the demand for emission free transportation has led to the development of electric vehicles. Improving the batteries’ cycling stability, capacity and safety have been the leading challenges to compete with gasoline and diesel engines. With advances in thin-film deposition techniques via atomic and molecular layer deposition, ultrathin films can be deposited to control the surface chemistry of the battery’s active materials. This thesis aims to understand two main aspects of molecular layer deposition. First, how it can influence solid electrolyte interface formation on the graphite surface during cycling in a lithium-ion battery. Utilizing physical and electrochemical testing it is shown that a conformal coating can be deposited on the graphite electrode, and graphite’s characteristic capacity decay can be eliminated increasing the battery’s longevity. Second, how the organic chain length in the hybrid organic-inorganic thin-films can influence the thin films structure after annealing in an oxygen rich atmosphere. Utilizing chemical and physical characterization techniques it is shown that a controllable surface area can be achieved.