ICT2014 Abstracts

 The emerging international demands on energy production have intensified interest on the power generation by thermoelectric technology. In various spectrum of temperature range the each thermoelectric material works, the power generation from high temperature of 300℃ to 800℃ are mainly interested in high efficiency and practical amount of electrical power generation.

 Many ceramic structure thermoelectric materials have been developed for this high temperature power generation usage. However these technologies inevitably have problems of oxidation and sublimation of thermoelectric materials and module components due to the high temperature operation. Two main approaches have been reported to come over these limiting factors. Classical approach utilizes “hermetic sealing” module structure which isolates the module from ambient oxygen by metallic housing and vacuum sealing. This hermetic sealing has its own issue on long term sealing capability and complexity of final power generation system. Other well-known technology is “module sealing” by high temperature anti oxidation materials like aero-gel. This aero-gel sealing on thermoelectric module has very reasonable results on high temperature operation, however several problems on micro crack and long term stability have to be research more.

 In this work the characteristics of ceramics coating on each thermoelectric leg itself is researched. Considering both oxygen blocking and thermal expansion coefficient to properly match the power generation legs, several ceramic based materials will be engineered from the powder phase to coated final thin coating layer. Several coating technologies (ex. Plasma spray coating) would be covered and resultant anti-oxidation and anti-sublimation performance of high temperature thermoelectric legs would be presented. Based on the anti-oxidation and anti-sublimation characteristics of this work, the possibility of new structural design for high temperature thermoelectric module will be discussed in the presentation.