Thermoelectric Material Phase Separation for Power Factor
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Solution Overview
Problem
Existing thermoelectric materials face a trade-off between increasing the Seebeck coefficient and maintaining electrical conductivity, limiting their thermoelectric performance.
Innovation Solution
A thermoelectric material with a dual-phase structure composed of a topological insulator (Ag2Te) and Bi0.5Sb1.5Te3, achieved through phase separation and pressure sintering, which enhances both Seebeck coefficient and electrical conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the Seebeck coefficient is increased in conventional thermoelectric materials, then thermoelectric performance improves, but electrical conductivity decreases
Solution Approach 1:
The patent employs a dual-phase composite material system consisting of a topological insulator phase (Ag2Te) and a semiconductor phase (Bi0.5Sb1.5Te3). The topological insulator phase provides high electrical conductivity through its surface states, while the semiconductor phase contributes to a high Seebeck coefficient. This composite structure allows simultaneous optimization of both electrical conductivity and Seebeck coefficient, resolving the traditional trade-off relationship between these parameters.
Solution Approach 2:
The patent creates distinct regions with different functional properties within the thermoelectric material. The topological insulator phase locally provides high electrical conductivity, while the semiconductor phase locally provides high Seebeck coefficient. This spatial separation of functions allows the material to achieve high power factor and high Seebeck coefficient simultaneously without the conventional trade-off.
2Reliability
If doping is applied to improve thermoelectric properties, then electrical conductivity increases, but Seebeck coefficient decreases
Solution Approach 1:
Instead of relying on doping of a single material phase, the patent uses a composite material system where the topological insulator phase (Ag2Te) and semiconductor phase (Bi0.5Sb1.5Te3) each contribute different properties. This approach avoids the trade-off inherent in doping, as the electrical conductivity is provided by the topological insulator's surface states while the Seebeck coefficient is provided by the semiconductor phase, allowing both parameters to be optimized simultaneously.
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
This approach significantly increases the power factor and figure of merit (ZT) of the thermoelectric material, breaking the trade-off between Seebeck coefficient and electrical conductivity, thus improving thermoelectric performance.
Implementation Method 1
a thermoelectric material having a composition represented by Chemical Formula 1: (TI) x (Bi 0.5 Sb 1.5-x Te 3-y ) 1-x wherein TI denotes a topological insulator comprising Ag 2 Te
Implementation Method 2
The Seebeck effect is a conversion of temperature differences directly into electricity, and has been applied to the field of power generation using an electromotive force generated due to a difference in temperature between both ends of a thermoelectric material
Implementation Method 3
The Peltier effect is an effect in which heat is produced at an upper junction and absorbed at a lower junction when an electric current is allowed to flow in a circuit
Data Source
Figure 1A
Figure 1B
Figure 1C
AI summary
According to an aspect of the present invention, disclosed is a thermoelectric material having a composition of chemical formula 1: [Chemical Formula 1] (TI)x(Bi0.5Sb1.5-xTe3-y)1-x wherein TI denotes a topological insulator.