This research project aims at investigating and demonstrating a new concept of manufacturing silicon (Si) anode lithium (Li) ion batteries by utilizing Si nanostructures on elastomeric substrates as anodes to release the stress induced by Li ion diffusion during charge-discharge cycles. Si anodes hold great promise and are being closely investigated for use in Li-ion batteries because they have the highest-known theoretical charge capacity. However, the development of Si-anode Li-ion batteries has lagged behind because of their large physical volume change (4X) during use, specifically during the insertion and extraction of Li ions, which results in pulverization and early capacity fading thus severely limiting their useful life. The objective of this collaborative project is to resolve the stress issue and manufacture Si-anode Li-ion batteries through a fundamental investigation of a novel concept of mechanical-electrochemical coupling of Si nanostructures on elastomeric substrates during insertion and de-insertion of Li ions. Specific studies will focus on (1) a theoretical understanding of releasing diffusion-induced stress using elastomeric substrates; (2) manufacturing of various Si nanostructures on elastomeric substrates as anodes in Li-ion batteries, (3) electrochemical characterization of Li-ion batteries with the nanostructured Si on elastomeric substrates as anode; and (4) development of a cost-effective approach and the realization of manufacturability.
If successful, the results of this collaborative research will facilitate the fundamental understanding in the coupled mechanical-electrochemical properties of Si nanostructures on elastomeric substrates and provide a powerful means to realize theoretically maximum energy density of Si-anode Li-ion batteries. Integrated, interactive and collaborative research and educational programs in two research institutions (University of Delaware and Arizona State University) will be established. The graduate and undergraduate students involved in the proposed research will be trained through a multidisciplinary and multi-university environment. The research achievement will be used to develop and enhance both undergraduate and graduate courses. An innovative outreach activity toward the general public will be established through the collaboration with the Arizona Science Center.
