Applying compliant compliant interfacial layers in thermoelectric devices

Abstract

A thermoelectric power generation technique is disclosed using one or more mechanically compliant and thermally and electrically conductive layers at the thermoelectric material interfaces to accommodate high temperature differentials and stresses induced thereby. The compliant material may be metal foam or metal graphite composite (e.g. using nickel) and is particularly beneficial in high temperature thermoelectric generators employing Zintl thermoelectric materials. The compliant material may be disposed between the thermoelectric segments of the device or between a thermoelectric segment and the hot or cold side interconnect of the device.

What is claimed is: 
     
         1 . A method of bonding thermoelectric materials, comprising the steps of
 bonding a compliant metal layer to a thermoelectric material for generating electrical power from heat; and   bonding an adjacent material to the compliant metal layer opposite the thermoelectric material such that the thermoelectric material and the compliant metal layer are thermally and electrically coupled;   wherein the compliant metal layer comprises a metal having a reduced density structure.   
     
     
         2 . The method of  claim 1 , wherein, wherein the reduced density structure is 60% or less of the metal as a solid. 
     
     
         3 . The method of  claim 1 , further comprising pressing the compliant metal layer to adjust thermal and electrical conductivity of the layer prior to bonding between the thermoelectric material and the adjacent material. 
     
     
         4 . The method of  claim 1 , wherein the compliant metal layer is bonded by brazing to the thermoelectric material and the adjacent material. 
     
     
         5 . The method of  claim 1 , wherein the adjacent material comprises a second thermoelectric material. 
     
     
         6 . The method of  claim 1 , wherein the thermoelectric material comprises Zintl. 
     
     
         7 . The method of  claim 1 , wherein the compliant metal layer comprises nickel. 
     
     
         8 . The method of  claim 7 , wherein the compliant metal layer comprises nickel foam. 
     
     
         9 . The method of  claim 7 , wherein the compliant metal layer comprises nickel graphite composite. 
     
     
         10 . The method of  claim 7 , wherein the compliant metal layer comprises nickel with less than 60% of the nickel as a solid. 
     
     
         11 . The method of  claim 10 , wherein the compliant metal layer comprises less than 30% of the nickel as a solid. 
     
     
         12 . The method of  claim 1 , wherein the compliant metal layer comprises copper. 
     
     
         13 . The method of  claim 12 , wherein the compliant metal layer comprises nickel with less than 60% of the nickel as a solid. 
     
     
         14 . The method of  claim 13 , wherein the compliant metal layer comprises less than 30% of the copper as a solid.