Exfoliation of layered-structured oxide Na_xCoO₂and its nano−block integration

Yoshiko Hamada , Yoshitake Masuda, KunihitoKoumoto

Department of Applied Chemistry, GraduateSchool of Engineering, Nagoya University, Nagoya 464-8603, Japan

Na_xCoO₂is one of the p-type thermoelectric oxide materials that show high electricalconductivity and large thermopower. However, its properties have not reachedthe level high enough for commercialization, so that further improvement inproperties is required. It is considered that the exfoliated nano blocks withnew chemical and physical properties different from a bulk can be integrated toconstruct novel materials with layered structures. Moreover, it is possible tosynthesize the materials having required properties by designing and combiningvarious nano blocks. We tried to synthesize CoO₂ nano blocks byexfoliation and reconstruct them with other building nano-blocks into a thinfilm with the use of electrophoresisto achieve better thermoelectric properties and develop new materials.