Synthesis of NaxCo2O4 thermoelectric oxide by the polymerized complex method and sps methods

Abstract

This chapter focuses on the synthesis of NaxCo2O4 thermoelectric oxide by the polymerized complex method and Spark Plasma Sintering (SPS) methods. The NaxCo2O4 thermoelectric oxide is synthesized by the polymerized complex (PC) process and SPS method. The effects of the PC and SPS method on the microstructure and thermoelectric properties of the sintered body are investigated. The PC+SPS sample have fine microstructure and high density as compared to the sample prepared by the conventional solid state reaction (SSR) method. However, the crystallographic anisotropy of the sintered body is deteriorated during SPS because of the short sintering time of SPS and partial decomposition of the NaxCo2O4 phase. The power factor of the PC+SPS sample is quite larger than that of the conventional SSR sample. Thermoelectric power generation, which can directly convert thermal energy into electrical energy, is recognized as a new energy conversion technique to utilize waste heat exhausted by automobiles and incinerators.