High efficiency thermoelectric power generation using zintl-type materials

Abstract

The invention disclosed herein relates to thermoelectrically-active p-type Zintl phase materials as well as devices utilizing such compounds. Such thermoelectric materials and devices may be used to convert thermal energy into electrical energy, or use electrical energy to produce heat or refrigeration. Embodiments of the invention relate to p-type thermoelectric materials related to the compound Yb 14 MnSb 11 .

1 . A thermoelectric device, comprising:
 a first substrate configured to operate at a first temperature;   a second substrate configured to operate at a second temperature, said second temperature being different from said first temperature to form a temperature gradient across said first substrate and said second substrate;   a p-type thermoelectric material disposed between said first substrate and said second substrate, said p-type thermoelectric material having a first end surface in thermal contact with said first substrate and a second end surface in thermal contact with said second substrate, said p-type thermoelectric material comprising a compound having the general formula (I)
   A 14 MPn 11   (I),
 
 wherein A is selected from the group consisting of calcium, strontium, barium, ytterbium, europium, lanthanum, and combinations thereof, 
 M is selected from the group consisting of manganese, zinc, aluminum, gallium, indium, scandium, cobalt, chromium, nickel, iron, and combinations thereof, and 
 Pn is selected from the elements nitrogen, phosphorus, arsenic, bismuth, antimony, gallium, germanium, tin, lead, selenium, tellurium, and combinations thereof; 
   an n-type thermoelectric material disposed between said first substrate and said second substrate, said n-type thermoelectric material having a first end surface in thermal contact with said first substrate and a second end surface in thermal contact with said second substrate;   an electrical conducting element to electrically connect said first surface of said p-type thermoelectric material with said first surface of said n-type thermoelectric material to provide a first electrical conduit therebetween; and   an electrical circuit, having a first terminal and a second terminal, said first terminal connecting to said second surface of said p-type thermoelectric material, said second terminal connecting to said second surface of said n-type thermoelectric material, to provide a second electrical conduit between said p-type thermoelectric material and said n-type thermoelectric material,   whereby said p-type thermoelectric material, said electrically conducting element, said n-type thermoelectric material, and said electrical circuit form an electrical loop through which an electrical current may travel.   
     
     
         2 . A thermoelectric device as in  claim 1 , wherein said p-type thermoelectric material and said n-type thermoelectric material are configured to transfer thermal energy from said first substrate to said second substrate and to generate said electrical current in a direction from said n-type thermoelectric material to said p-type thermoelectric material. 
     
     
         3 . A thermoelectric device as in  claim 1 , wherein said electrical circuit further comprises a DC power supply to drive said electrical current to flow in a direction from said n-type thermoelectric material to said p-type thermoelectric material. 
     
     
         4 . A thermoelectric device as in  claim 1 , wherein said electrical circuit further comprises a DC power supply to drive said electrical current to flow in a direction from said p-type thermoelectric material to said n-type thermoelectric material. 
     
     
         5 . The thermoelectric device of  claim 1 , wherein the p-type thermoelectric material, the n-type thermoelectric material, or both are segmented. 
     
     
         6 . The thermoelectric device of  claim 1 , wherein A is ytterbium. 
     
     
         7 . The thermoelectric device of  claim 1 , wherein Pn is antimony. 
     
     
         8 . The thermoelectric device of  claim 1 , wherein the p-type thermoelectric material has the general formula (II)
   Yb 14-y A′ y Mn 1-x M′ x Sb 11   (II),
   wherein A′ is selected from the group consisting of calcium, europium, lanthanum, and combinations thereof;   M′ is selected from the group consisting of zinc, aluminum, and combinations thereof;   y is from about 0.0 to about 14.0; and   x is from about 0.0 to about 1.0.   
     
     
         9 . The thermoelectric device of  claim 1 , wherein the p-type thermoelectric material comprises a compound according to the general formula III
   Yb 14 Mn 1-x Zn x Sb 11   (III),
   wherein x is from about 0.0 to about 1.0.   
     
     
         10 . The thermoelectric device of  claim 1 , wherein the p-type thermoelectric material comprises a compound according to the general formula IV
   Yb 14 Mn 1-x Al x Sb 11   (IV),
   wherein x is from about 0.0 to about 1.0.   
     
     
         11 . The thermoelectric device of  claim 1 , wherein the p-type thermoelectric material comprises Yb 14 MnSb 11 . 
     
     
         12 . The thermoelectric device of  claim 1 , wherein the p-type thermoelectric material comprises Yb 14 ZnSb 11 . 
     
     
         13 . A thermoelectrically active p-type thermoelectric material having the general formula (I):
   A 14 MPn 11   (I),
   wherein A is selected from the group consisting of calcium, strontium, barium, ytterbium, europium, lanthanum, and combinations thereof;   M is selected from the group consisting of manganese, zinc, aluminum, gallium, indium, scandium, cobalt, chromium, nickel, iron, and combinations thereof; and   Pn is selected from the elements nitrogen, phosphorus, arsenic, bismuth, antimony, gallium, germanium, tin, lead, selenium, tellurium, and combinations thereof.   
     
     
         14 . The p-type thermoelectric material of  claim 13 , wherein the thermoelectric material has a thermoelectric figure of merit (zT) of at least about 0.6 and a thermoelectric power generation compatibility factor (s) of at least about 1 V −1 , at a temperature above about 898 K. 
     
     
         15 . The p-type thermoelectric material of  claim 13 , wherein 1 to 10% by weight of the thermoelectric material is replaced by dopants. 
     
     
         16 . The p-type thermoelectric material of  claim 13 , wherein 0.05 to 1% by weight of the thermoelectric material is replaced by dopants. 
     
     
         17 . The p-type thermoelectric material of  claim 13 , wherein A is ytterbium. 
     
     
         18 . The p-type thermoelectric material of  claim 13 , wherein Pn is antimony. 
     
     
         19 . A thermoelectrically active p-type thermoelectric material comprising the general formula (II):
   Yb 14-y A′ y Mn 1-x M′ x Sb 11   (II),
   wherein A′ is selected from the group consisting of calcium, europium, lanthanum, and combinations thereof;   M′ is selected from the group consisting of zinc, aluminum, and combinations thereof;   y is from about 0.0 to about 14.0; and   x is 0.0 or 1.0.   
     
     
         20 . The p-type thermoelectric material of  claim 19 , wherein the thermoelectric material has a thermoelectric figure of merit (zT) of at least about 0.6 and a thermoelectric power generation compatibility factor (s) of at least about 1 V −1 , at a temperature above about 898 K. 
     
     
         21 . A p-type thermoelectric material, wherein the thermoelectric material has a thermoelectric figure of merit (zT) of at least 0.6 and a thermoelectric power generation compatibility factor (s) of at least 1, at a temperature above 898 K. 
     
     
         22 . The p-type thermoelectric material of  claim 21  wherein the thermoelectric material comprises a compound having the general formula (I)
   A 14 MPn 11   (I),
 
 wherein A is selected from the group consisting of calcium, strontium, barium, ytterbium, europium, lanthanum, and combinations thereof, 
 M is selected from the group consisting of manganese, zinc, aluminum, gallium, indium, scandium, cobalt, chromium, nickel, iron, and combinations thereof, and 
 Pn is selected from the elements nitrogen, phosphorus, arsenic, bismuth, antimony, gallium, germanium, tin, lead, selenium, tellurium, and combinations thereof. 
 
     
     
         23 . A method of producing an electrical current, comprising:
 providing a thermoelectric device, comprising
 a first substrate configured to operate at a first temperature, 
 a second substrate configured to operate at a second temperature, said second temperature being different from said first temperature to form a temperature gradient across said first substrate and said second substrate, 
 a p-type thermoelectric material disposed between said first substrate and said second substrate, said p-type thermoelectric material having a first end surface in thermal contact with said first substrate and a second end surface in thermal contact with said second substrate, said p-type thermoelectric material comprising a compound having the general formula (I)
   A 14 MPn 11   (I),
 
 
 wherein A is selected from the group consisting of calcium, strontium, barium, ytterbium, europium, lanthanum, and combinations thereof, 
 M is selected from the group consisting of manganese, zinc, aluminum, gallium, indium, scandium, cobalt, chromium, nickel, iron, and combinations thereof, and 
 Pn is selected from the elements nitrogen, phosphorus, arsenic, bismuth, antimony, gallium, germanium, tin, lead, selenium, tellurium, and combinations thereof; and 
   operating the thermoelectric device to produce an electrical current.