PHENOLIC RESIN/POLYHEDRAL OLIGOMERIC SILSESQUIOXANE (POSS) HYBRID NANOCOMPOSITES AND ADVANCED COMPOSITES FOR USE AS ANODE MATERIALS IN LITHIUM ION BATTERIES

by Lee, Sang Ho

The work presented in this thesis can be divided into two research areas. First, two sets of organic-inorganic hybrid nanocomposites containing phenolic resin/trisilanolphenyl-POSS and phenolic resin/octa(aminophenyl)-T8-POSS nanocomposites were synthesized and the morphology and properties were investigated. Octa(aminophenyl)-T8-polyhedral silsesquioxane is an octafunctional-T8-POSS containing eight aniline-like amino groups, one on each corner silicon atom. It was synthesized in our laboratory by an improved two-step reaction sequence; nitration (HNO3) and reduction (HCOOH/Et3N). Varying amounts of POSS were codissolved with a resole phenolic resin in organic solvent. This was followed by solvent removal and thermal curing. Intermolecular interactions in these nanocomposites were probed by FT-IR. The micro-morphology and aggregation state of POSS were investigated using SEM, TEM, and WAXD studies. The thermal and mechanical properties and thermal stabilities of these composites were investigated by DMTA, DSC, and TGA. Second, two types of carbon-covered mono- and bimetallic (Sn, and Sn/Sb alloy) nanorods for use as anode materials in lithium ion batteries were synthesized by a thermal chemical vapor deposition method. Commercial antimony and tin oxide (Sb3O4/SnO2) nanopowders and added tin (IV) oxide (SnO2) nanoparticles (~19 nm) were used as the precursors for the growth of bimetallic Sn/Sb alloy and monometallic Sn nanorods, respectively. In addition, the shape of the products recovered were different when different hydrocarbon gas flow rates were used for growing intermetallic nanorods in carbon templates. Acetylene and methane were the gases tried. The morphologies and structures of the intermetallic nanorods in carbon templates were investigated using SEM and TEM and proved by X-EDS, XRD, and XPS studies.