Office of Technology Transfer – University of Michigan

Stabilized Copper Selenide Thermoelectric Materials and Methods of Fabrication

Technology #2018-251

Thermoelectric generators (TEGs) are devices that directly convert heat to electricity and have been useful for generating power from waste heat and in remote or otherwise inhospitable environments. They offer the promise of widespread power generation from waste heat sources in a variety of industries, such as manufacturing (automobile, steel, etc.). The widespread deployment of TEGs has been hampered by the fact that the best thermoelectric materials contain lead, an increasingly regulated and recognized health hazard. Many of the candidate materials to replace current lead-containing TEG devices suffer from intrinsic chemical instability at elevated temperatures. This includes copper selenide (Cu2Se), which is well known for its high figure of merit (ZT) value (indicating excellent performance in TEGs) and poor chemical stability.


Enhanced stability and thermoelectric properties of new Cu2Se material

The available technology is a p-type thermoelectric material composed of earth-abundant metals that has excellent figures of merit over a range of operating temperatures from 25-575 °C. The material demonstrates remarkable chemical and structural stability, addressing one of the largest areas of concern for competing thermoelectric materials generated from earth-abundant metals. The excellent stability and thermoelectric properties of the material is a result of the inclusion of nanometer-scale inclusions within the bulk material that are generated during the manufacturing process by the addition of a metal that has poor solubility within the bulk material. From a manufacturing perspective, production is a relatively straightforward two-step process that should be readily scalable to large production formats.

The available technology is an excellent material for the p-type component of a TEG. Development of a complementary n-type material that is also lead-free will enable a fully lead-free, stable, and high performing TEG device. Such a device will be essential for the expanded use of TEGs in industries ranging from consumer electronics and medical devices to the automotive and large-scale power production industries.

Applications

  • Lead-free thermoelectric generators (TEGs) 
  • Scavenging of waste heat in industrial operations (manufacturing, automotive, etc.)
  • Consumer electronics, medical devices
  • Electrical power generation in remote and inhospitable environments

Advantages

  • High ZT, p-type thermoelectric material over a broad temperature range (25-575 °C)
  • Does not contain lead, a highly regulated and toxic metal
  • Uses environmentally friendly, low cost, earth-abundant metals
  • Excellent chemical and structural stability over a range of operating temperatures
  • Straightforward manufacturing process, readily adaptable to large-scale production