Fabrication of nanostructures for energy storage and conversion devices

Abstract

Compared with all the other technical issues facing us in the world today, energy is one of the most important issues. Nanotechnology gives much potential chances to solve the energy problems. The limitations of energy storing density can be overcome by applying nanostructured materials to the batteries. Energy conversion efficiency of polymer solar cells can be increased by controlling the structure of solar cell components. In this thesis, some novel nanotechnology applications are introduced to energy storage devices or energy conversion devices. After a brief explain and overview about whole researches in this thesis at chapter 1, two nanotechnology applications regarding tin nanoparticle anode for lithium secondary battery are discussed at chapter 2 and 3. A novel nanoparticle thin film electrode fabrication method and metal nanoparticle / carbon nanotube composite system bring high performance lithium battery electrode. The next three chapters (chapter 4, 5, and 6) are related to nanotechnology application to organic solar cells. Nanoimprinting with commercially available AAO (anodized aluminum oxide) membrane filter on photoactive layer gives higher power conversion efficiency. Nanoscale titanium sub-oxide layer acts as a hole blocking layer and it is confirmed by analysis of dark current behavior. In addition, a method for more accurate measurement is proposed and discussed. A novel method for fabricating tin nanoparticle thin film electrodes that show good performance in lithium ion batteries during cycling is reported. The vacuum filtration method has the advantage affording a high degree of dispersion of the electrode components, thereby providing good electrical contacts between the tin nanoparticles and the conductive carbon or current collector. Hybrids consisting of single-walled carbon nanotubes (SWNTs) and tin nanoparticles were prepared on substrates as anode materials for lithium-ion batteries with two different techniques: 1) hybrid c...