Materials Transactions Online

Materials Transactions, Vol.46 No.07 (2005) pp.1453-1455
© 2005 The Thermoelectrics Society of Japan

Preparation and Thermoelectric Properties of NaxCoO2/Co3O4 Layered Nano-Composite

Peixin Zhu1, Takahiro Takeuchi1,, Hiromichi Ohta1,2, Won-Seon Seo3 and Kunihito Koumoto1,2,

1Graduate School of Engineering, Nagoya University, Nagoya 464-8603, Japan
2CREST, Japan Science and Technology Agency, Kawaguchi 332-0012, Japan
3Korea Institute of Ceramic Engineering and Technology, 233-5 Gasan-Dong, Guemcheon, Seoul 153-801, Korea

NaxCoO2/Co3O4 layered nano-composite was prepared through the exfoliation, stacking, and sintering processes. Although almost no electrical conduction was observed at low temperatures, a significant increase in conductivity was observed above 750 K, and it reached 1.2× 102 Scm-1 at 1200 K, which is comparable to that of Na0.7CoO2. Seebeck coefficient also largely increased above 750 K. This observation might be associated with the electrical behaviors of Co3O4 at high temperature.

(Received 2004/10/20; Accepted 2005/3/13; Published 2005/7/15)

Keywords: sodium cobaltite, thermoelectric properties, exfoliation, integration, nano sheet

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