| This dissertation provides background information on nanoscale science, the template synthesis of nanomaterials, and its application to Li-ion battery and membrane transport. My work has shown that compared with conventional thin-film electrodes with the same mass, the template-synthesized SnO 2 nanofibers and the nanoporous carbon-honeycomb have much higher rate capability and cycling performance as Li-ion battery anodes. This is because the high-rate capacity of Li-ion battery is limited by slow solid-state Li + diffusion in electrode materials, and the nanostructured electrodes decrease the distance that Li+ must diffuse in the solid state. Furthermore, the surface area of the nanostructured electrode was larger, making the effective current-density during discharge smaller than that for a conventional electrode. Better cycling performance was achieved because the spaces between the nanostructures of electrode materials could accommodate the volume changes due to Li+ insertion and extraction through the electrode materials.; In an effort to combine the advantages of both nanostructured electrodes and all-solid-state Li-ion batteries, a nanostructured all-solid-state Li-ion battery was investigated. This battery was designed to use the carbon honeycomb as the anode and the substrate; the surface and the inner walls of the carbon honeycomb were then covered with an ultrathin electrochemically polymerized poly(phenylene oxide) (PPO) film, which was used as the solid electrolyte. The PPO film was very thin (0.5–1.9 nm) and could be easily deposited into the inner walls of the carbon honeycomb. PPO film was only conductive to cations (e.g., Li+) after sulfonation.; My research also showed that O2 plasma etching could be used to prepare not only the carbon honeycomb anode but also nanostructured conical pores in polymeric membranes. Conical pore embedded membranes can be used for enhanced membrane transport and resistive-pulse sensing of particles such as molecules and ions. The plasma etch method provides a simple and convenient route for preparing conical-nanopore membranes. |
