Core-Shell Thermoelectric Material Phonon Scattering
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Solution Overview
Problem
Current thermoelectric materials face a trade-off between Seebeck coefficient, electrical conductivity, and thermal conductivity, making it difficult to achieve high energy conversion efficiency, and nanostructures are challenging to manufacture in bulk quantities.
Innovation Solution
A thermoelectric material with a two-dimensional nanostructure core/shell structure is developed, where the shell is grown epitaxially on the core to inhibit electron scattering and enhance phonon scattering, improving the figure of merit by selectively transporting electronic carriers and blocking thermal transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a thermoelectric material is designed to increase Seebeck coefficient and electrical conductivity, then energy conversion efficiency improves, but thermal conductivity increases which reduces the figure of merit
Solution Approach 1:
The material is segmented into multiple grains with specific orientation relationships, creating grain boundaries that scatter phonons while maintaining electron transport. The segmentation into oriented grains allows selective filtering of heat-carrying phonons without blocking charge carriers, thus reducing thermal conductivity while preserving electrical conductivity for improved energy conversion efficiency.
Solution Approach 2:
The patent introduces local quality variations through specific grain orientation relationships and boundary characteristics. Certain grain boundaries are engineered to have properties that preferentially scatter phonons while allowing electron transport, creating localized regions with different thermal and electrical transport properties. This local quality differentiation enables the material to achieve high Seebeck coefficient and electrical conductivity while maintaining low thermal conductivity.
2Temperature
If nanostructures are used to decrease thermal conductivity through phonon scattering, then figure of merit improves, but manufacturing difficulty increases and bulk production becomes challenging
Solution Approach 1:
The patent employs a self-organizing mechanism where the material naturally forms the desired nanostructure during solidification and cooling processes. The specific grain orientation relationships emerge spontaneously under controlled cooling conditions, eliminating the need for complex external nanostructuring equipment or post-processing steps. This self-service approach enables bulk production of materials with engineered phonon scattering characteristics while maintaining ease of manufacture through conventional solidification processes.
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 core/shell nanostructure effectively increases the figure of merit by improving Seebeck coefficient and electrical conductivity while reducing thermal conductivity, enabling efficient energy conversion and easy bulk manufacturing.
Implementation Method 1
the shell is grown epitaxially on the core to inhibit electron scattering and enhance phonon scattering
Implementation Method 2
an intergranular density of the nanostructure increases, which increases the scattering of phonons at an interface of the nanostructure. In this regard, thermal conductivity can be decreased
Implementation Method 3
the Seebeck effect, in which an electromotive force is generated due to a temperature difference between the ends of the dissimilar materials that are connected
Implementation Method 4
the Peltier effect, in which two dissimilar materials are connected and heat is released or absorbed due to a current applied from the outside
Data Source
AI summary
A thermoelectric material including: a two dimensional nanostructure having a core and a shell on the core. Also, a thermoelectric element and a thermoelectric apparatus including the thermoelectric material, and a method of preparing the thermoelectric material.