N-type Thermoelectric Material via Ferrocyanide Doping

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Solution Overview

Problem

There is a demand for a technique to convert nanomaterials exhibiting p-type conductivity into those exhibiting n-type conductivity for enhanced thermoelectric conversion performance, as existing thermoelectric conversion elements require both p-type and n-type materials, and nanomaterials often exhibit p-type conductivity.

Innovation Solution

An n-type material for thermoelectric conversion is achieved by doping a p-type material containing carbon nanotubes and a conductive resin with a dopant comprising a complex ion anion, an alkali metal cation, and a cation scavenger, such as ferrocyanide ions and crown ether-based compounds, which changes the Seebeck coefficient from positive to negative, thereby converting p-type to n-type conductivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a p-type nanomaterial is used for thermoelectric conversion, then the material can be easily synthesized with high conductivity, but the thermoelectric conversion performance is limited due to lack of n-type conductivity

Engineering Contradiction:
Improvethermoelectric conversion performanceVSAvoidconductivity type
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent changes the electrical conductivity parameter of the nanomaterial from p-type to n-type by introducing a dopant containing ferrocyanide ions. This parameter change enables the material to achieve negative Seebeck coefficient and n-type conductivity, thereby improving thermoelectric conversion performance while maintaining the nanomaterial's inherent high conductivity characteristics

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses a dopant containing ferrocyanide ions as an intermediary substance to convert the conductivity type of the nanomaterial. The dopant acts as a mediator that introduces charge carriers and changes the electrical properties of the carbon nanotube-based material from p-type to n-type without fundamentally altering the nanomaterial structure

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If a dopant is introduced to convert p-type conductivity to n-type conductivity, then n-type material can be obtained, but the manufacturing process becomes more complex

Engineering Contradiction:
Improven-type conductivity achievementVSAvoiddoping process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple functions into the dopant formulation: the dopant simultaneously provides ferrocyanide ions for n-type conversion, maintains nanomaterial dispersion, and ensures uniform doping. This merging of functions into a single dopant component simplifies the overall manufacturing process despite achieving complex n-type conversion

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent optimizes the dopant concentration parameter to achieve effective n-type conversion without excessive processing steps. By controlling the dopant amount within a specific range, the patent achieves reliable n-type conductivity while keeping the manufacturing process manageable and scalable

Inventive Principle:
Principle #35Parameter changes

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 solution provides a thermoelectric conversion element with excellent performance by effectively converting p-type materials to n-type, improving electric conductivity and storage stability, and enabling the production of high-performance n-type materials for thermoelectric conversion.

Implementation Method 1

doping a p-type material for thermoelectric conversion with a dopant, the p-type material for thermoelectric conversion containing a carbon nanotube and a conductive resin, in which the dopant contains an anion that is a complex ion, an alkali metal cation, and a cation scavenger

Methodology Applied
Scientific EffectDoping: Dopants

Implementation Method 2

Thermoelectric conversion is a technique for directly converting heat into electricity by utilizing a Seebeck effect

Methodology Applied
Scientific EffectSeebeck effect: Seebeck Effect

Data Source

PatentUS12108676B2N-type material for thermoelectric conversion, method for producing same, dopant and thermoelectric conversion element
Publication Date: 2024.10.01 DENKA CO LTD

AI summary

An n-type material for thermoelectric conversion obtained by doping a p-type material for thermoelectric conversion with a dopant, the p-type material for thermoelectric conversion containing a carbon nanotube and a conductive resin, in which the dopant contains an anion that is a complex ion, an alkali metal cation, and a cation scavenger.