Ordered Three-Dimensional Carbon-Based Multifunctional Nanohybrids For Energy Storage
Nanostructures of countless materials have been studied extensively over the past decades for their interesting and highly tunable properties that go far beyond their characteristics in the bulk. While the variety of reported nanostructures, morphologies, and porosities is vast, little is still understood regarding the structure-property relationships for nanomaterials in energy storage. Furthermore, the potentials of multi-component nanohybrids, including complete nanodevices, are not fully explored. Block copolymer structure direction of inorganic nanomaterials provides a synthetic pathway for precise control over many relevant parameters. In this thesis, the highly tunable synthesis of ordered mesoporous carbons from the self-assembly and structure direction of triblock terpolymers and phenolic resols is described. The tailorability of porosity, pore size, surface area, chemical composition, and morphology by design is demonstrated, including two different gyroidal carbons. These mesoporous carbon materials with a wide range of characteristics are employed in a structure-property relationship study as sulfur hosts in lithium-sulfur batteries. This methodological investigation demonstrates the beneficial impact of microporosity and low carbonization temperature, which influences the chemical composition of the carbon material, on cyclability and capacity retention of carbon-sulfur composite cathodes. To extend the idea of three-dimensionally ordered multi-component nanomaterials that combine and potentially enhance the functionality of its individual components, atomic layer deposition is investigated towards its applicability on nanoporous materials. It is shown that a conformal, nanometer thin titanium dioxide coating on gyroidal mesopores can be achieved over microns in deposition depth on free-standing carbonaceous substrates. The obtained ordered gyroidal mesoporous core-shell hybrid exhibit triplefunctionality with a graphitized carbon core, crystallized anatase-titania shell, and a continuous mesoporous phase. With the inclusion of a third solid phase in the gyroidal architecture the complexity of ordered multicomponent nanostructures is further increased. The "total synthesis" of a 3D-nanointegrated allsolid-state battery is described using almost entirely polymer based processing and materials. Freestanding gyroidal mesoporous carbon is used as the anode of a lithium ion battery and coated with an ultra-thin polymer electrolyte through self-limiting electropolymerization. The 3D-battery architecture is completed by backfilling the resulting mesoporosity of the anode-electrolyte assembly with sulfur and insitu polymerized conducting polymer.
Block Copolymer Self-Assembly; Gyroidal three-dimensional Carbons; Funcitonal Nanomaterials for Batteries
Disalvo,Francis J; Abruna,Hector D
Chemistry and Chemical Biology
Ph.D. of Chemistry and Chemical Biology
Doctor of Philosophy
dissertation or thesis