(407a) Synthesis of Metal Oxide Coatings on Silicon Nanoparticles Via Condensed Layer Deposition for Enhanced Lithium-Ion Battery Anodes

Silicon-based lithium-ion batteries (LIBs) are considered by many to be the future of LIBs due to silicon’s high theoretical capacity of ~ 4200 mAh/g. However, upon lithiation, silicon expands by approximately 300% which can cause destruction of an LIB anode thus preventing commercial applications. As such, this project aimed to apply the thin coating technique known as the Condensed Layer Deposition (CLD) method to synthesize conductive, uniform metal oxide nanocoatings on the surface of silicon nanoparticles (SiNPs) to create more cycle stable silicon-based anodes in LIBs. Transmission electron microscopy (TEM) studies have shown that uniform coatings on the order of 2-5nm in thickness can be synthesized. Process optimization has determined that the condensation of a thin water film on the SiNP substrate is the rate determining step. High-resolution TEM and energy dispersive X-ray spectroscopy have also confirmed the presence of a uniform metal oxide coating on the surface of the SiNPs. Additional characterization of these coated SiNPs will be performed via powder X-ray diffraction and thermogravimetric analysis. The changes in cycle stability of anodes constructed from pure SiNPs versus those constructed from metal oxide-coated SiNPs are tested using coin-type half-cell electrochemical testing.