Stabilized Copper Selenide Nanocomposite for Thermoelectric Generators
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Solution Overview
Problem
Current thermoelectric materials, such as copper selenide (Cu2Se), suffer from poor chemical and structural stability at high temperatures, limiting their deployment in mainstream thermoelectric generators due to selenium evaporation and copper diffusion, which hampers the development of efficient and cost-effective thermoelectric energy conversion technology.
Innovation Solution
A nanocomposite thermoelectric material is developed by incorporating foreign metals like indium into the copper selenide matrix, forming coherent nanoscale inclusions that stabilize the material and enhance its figure of merit, achieved through a sequential solid-state transformation process, resulting in a Cu2Se matrix with CuInSe2 nanoinclusions that improve electrical conductivity and reduce thermal conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If copper selenide (Cu2Se) is used as a thermoelectric material to achieve high figure of merit, then electrical conductivity and Seebeck coefficient are improved, but chemical stability deteriorates due to selenium evaporation and copper diffusion at high temperatures
Solution Approach 1:
The patent creates a nanocomposite material consisting of a copper selenide matrix with embedded foreign metal inclusions (such as indium, aluminum, gallium, antimony, or bismuth). This composite structure combines the high figure of merit of copper selenide with the thermal stability of foreign metals, preventing selenium evaporation and copper diffusion while maintaining thermoelectric performance.
2Reliability
If copper selenide (Cu2Se) is used to achieve high figure of merit, then electrical conductivity is improved, but structural stability deteriorates due to copper diffusion at high temperatures
Solution Approach 1:
The patent extracts or removes the problematic copper diffusion pathway by introducing foreign metal inclusions that act as barriers. These inclusions prevent copper atoms from diffusing through the crystal lattice at high temperatures, thereby maintaining structural stability while preserving the electrical conductivity needed for thermoelectric function.
3Reliability
If higher ZT values (2-3) are targeted to achieve efficiencies comparable to other power generation methods, then thermoelectric performance is improved, but material stability deteriorates
Solution Approach 1:
The patent applies local quality by creating regions with different properties within the material. The foreign metal inclusions are distributed locally throughout the copper selenide matrix, providing localized stability zones that prevent degradation while allowing the bulk material to maintain high thermoelectric performance. This local modification approach enables achieving ZT values of 2-3 without sacrificing overall material stability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The nanocomposite exhibits a record-high average figure of merit (ZT) of approximately 1.5 over a broad temperature range, significantly increasing chemical stability and efficiency, making it suitable for large-scale thermoelectric generator applications.
Implementation Method 1
The Seebeck effect, which refers to the direct conversion of heat into electricity at the junction of distinct materials, is the atomic driving force for devices known as thermoelectric generators
Implementation Method 2
The inverse is the Peltier effect, in which the flow of a current between the junction of two distinct materials may cause a release or absorption of heat
Data Source
AI summary
A thermoelectric composition is provided that includes a nanocomposite comprising a copper selenide (Cu2Se) matrix having a plurality of nanoinclusions comprising copper metal selenide (CuMSe2) distributed therein. M may be selected from the group consisting of: indium (In), aluminum (Al), gallium (Ga), antimony (Sb), bismuth (Bi), and combinations thereof. The thermoelectric composition has an average figure of merit (ZT) of greater than or equal to about 1.5 at a temperature of less than or equal to about 850K (about 577° C.). Methods of making such a thermoelectric nanocomposite material by a sequential solid-state transformation of a CuSe2 precursor are also provided.