220 拡散接合を利用したNi-AL積層構造の熱電デバイスへの応用

Abstract

The thermoelectric power generation device can take out electric energy from thermal energy directly. In order to transform a difference of temperature into electric power efficiently, it is common to make the thermoelement of N-type and P-type into pi structure. Since the thermoelectric power of an element was small, much pi structures needed to be connected with series, but when a large number were connected with series, there was a problem that internal resistance will become large. Under these circumstances, a new structure which used SPS for N-type(nickel) and P-type(Bi0.5Sbl.5Te3) by kanno et. al in 2012, and was laminated directly was proposed[l]. With this structure, the direction and the output voltage direction of a difference of temperature lie at right angles, the effective difference of temperature which contributes to power generation becomes very small, and efficiency is disadvantageous. However, in order to bond directly the elements connected with silver paste until now by spark plasma sintering(SPS), internal resistance does not become so large although more than one are connected in series. In this research, the low cost nickel/aluminum lamination TE power generation device which used the diffusion bonding instead of SPS and joined aluminum to nickel directly is proposed. Although the Seebeck coefficient of nickel and aluminum used this time is low compared with a general thermoelectric material, considering material cost and a manufacturing cost, it can use enough as a power generation device. Moreover, it is possible by optimizing the thickness of nickel and aluminum, and a lamination angle to raise conversion efficiency.