STUDY OF CATALYTIC GROWTH OF OLEFIN NANO FIBRILS AND CARBON NANO FIBRILS OVER SOLID SURFACE AND ITS APPLICATION

Unlike many conventional olefin reactors, the reaction temperature, heat transfer and bimodal distribution of polymer molecular weight can easily be controlled in the micro/milli reactor systems developed during this study. The catalytic growth of carbon nano fibrils on silicon has been investigated for application as anode materials in Li-ion batteries. This research is aimed at developing a binder free silicon anode system that consists of a modified Cu foil (current collector), Si nanoparticles (SiNPs), and carbon nanotubes (CNTs).

This anode system includes the nanostructured Cu surface layer as a hub for the Si nanoparticles that undergo deformation and fragmentation during the charge/discharge cycles. SiNPs are deposited with Fe-Co bimetallic catalyst and CNTs are grown in situ at the catalyst sites. The surface layer of the Cu is modified via an oxidation and reduction processes to have knife-like nanostructures with high void fractions.

The SiNPs are deposited on/in to the nanostructured Cu foil without any binders. The CNTs growing at the surface of the SiNPs serve as the electron conductor and also holds the SiNP during the lithiation/delithiation cycles. Since Si/CNT particles are surrounded by thin protrusions on the surface of Cu current collector, the maximum connectivity between silicon and current collector can be obtained, and excellent cycle stability of the battery can be maintained without any binders.