Thermoelectric Material Lattice Constant Optimization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing thermoelectric conversion materials face challenges in optimizing carrier density and reducing thermal conductivity, making it difficult to enhance the efficiency of thermoelectric conversion modules, particularly when using chimney ladder type compounds as mother materials.
Innovation Solution
A thermoelectric conversion material configuration involving a mother phase with a chimney ladder type compound and an additive phase at the grain boundary, where the mother phase contains a third element to alter the lattice constant and the additive phase contains the second element, allowing for controlled composition ratios to optimize carrier density and reduce thermal conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a chimney ladder type compound is used as a thermoelectric conversion material, then the material structure is well-defined and stable, but the carrier density cannot be easily optimized and thermal conductivity cannot be effectively reduced
Solution Approach 1:
The patent introduces a third element at specific lattice sites within the chimney ladder structure to locally modify the crystal lattice constant. This local modification optimizes carrier density and electrical conductivity without disrupting the overall structural stability of the mother phase, thereby resolving the contradiction between structural reliability and conversion efficiency.
Solution Approach 2:
The patent creates a composite thermoelectric material by combining the chimney ladder type compound (mother phase) with a second element-containing phase. This composite structure allows the third element to modify the lattice constant for optimized carrier density while the composite nature reduces thermal conductivity, thus improving overall thermoelectric efficiency while maintaining structural stability.
2Productivity
If the composition ratio of the chimney ladder type compound is adjusted to optimize carrier density, then the output factor S2/ρ improves, but the thermal conductivity may increase
Solution Approach 1:
The third element is introduced at specific lattice positions to locally alter the lattice constant, which optimizes carrier density and improves the output factor S2/ρ. This localized modification allows independent optimization of electrical properties without proportionally increasing thermal conductivity, as the structural framework remains intact.
Solution Approach 2:
By forming a composite material with the second element, the patent creates interfaces and heterostructures that scatter phonons (heat carriers) while maintaining electron transport. This composite approach allows the optimization of electrical conductivity (improving S2/ρ) while simultaneously reducing thermal conductivity through interface scattering and compositional modulation.
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 configuration enables improved thermoelectric performance by adjusting the composition ratio of the chimney ladder type compound, maximizing the output factor S2/ρ and maintaining efficiency even at high temperatures, thus enhancing the overall performance of thermoelectric conversion modules.
Implementation Method 1
a technology to realize this is a thermoelectric conversion system comprising a thermoelectric conversion module (thermoelectric conversion element) using Seebeck effect
Data Source
AI summary
The present invention improves the performance of a thermoelectric conversion material and a thermoelectric conversion module. A thermoelectric conversion material has a mother phase containing a chimney ladder type compound comprising a first element of groups 4 to 9 and a second element of groups 13 to 15 and an additive phase existing at a grain boundary of the mother phase, the mother phase contains a third element to change a lattice constant of the chimney ladder type compound, and the additive phase contains the second element.