Variable-Resistivity Conductive Member for Fuel Cell Heat Balancing

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Solution Overview

Problem

Fuel cell stack devices face durability issues due to temperature variations during power generation, which affect their performance and longevity.

Innovation Solution

An electrically conductive member with distinct portions having different resistivities is integrated between cells in the fuel cell stack, with the higher resistivity portion connected to the hotter part to reduce temperature variations and prevent excessive heating, thereby enhancing durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a uniform electrically conductive member is used in the fuel cell stack, then the electrical connection is simple and consistent, but temperature variations cause excessive heating and reduced durability in critical areas

Engineering Contradiction:
ImprovedurabilityVSAvoidstructure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The electrically conductive member is designed with different resistivity values in different regions. The first portion has a first resistivity while the second portion has a second resistivity different from the first. This local variation in electrical properties allows critical areas to have higher resistivity for heat generation when needed, while non-critical areas maintain lower resistivity for efficient current conduction, thereby improving overall durability without excessive complexity

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The electrically conductive member is divided into distinct portions (first portion and second portion) with different resistivity characteristics. This segmentation allows each portion to be optimized for its specific function: one portion for heat generation in critical areas and another for efficient current conduction in non-critical areas, resolving the contradiction between reliability and device complexity

Inventive Principle:
Principle #1Segmentation

2Temperature

If the resistivity is increased in hot areas to reduce temperature rise, then temperature control improves, but electrical conductivity decreases

Engineering Contradiction:
Improvetemperature riseVSAvoidelectrical conductivity
Core Design Contradiction:
TemperatureVSLoss of energy

Solution Approach 1:

Different portions of the electrically conductive member have different resistivity values tailored to their specific needs. The first portion with first resistivity is positioned in areas requiring temperature control, while the second portion with second resistivity is positioned in areas requiring efficient current conduction. This local differentiation allows simultaneous optimization of temperature control and electrical conductivity in different regions

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The resistivity parameter of the electrically conductive member is varied spatially across different portions. By changing the resistivity parameter from one value in the first portion to another value in the second portion, the system achieves both temperature control in hot areas and maintained electrical conductivity in other areas, resolving the contradiction between temperature management and energy efficiency

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 effectively reduces temperature rise in critical areas, improving the durability and performance of the fuel cell stack by managing energization and heat distribution, leading to increased operational stability and longevity.

Implementation Method 1

A resistivity of the first portion is larger than a resistivity of the second portion... reduces a temperature rise in a critical area

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP4492507A1Electroconductive member, electrochemical cell device, module, and module accommodation device
Publication Date: 2025.01.15 KYOCERA CORP
  • EP4492507A1 patent drawingFigure 1A~1B
  • EP4492507A1 patent drawingFigure 1C
  • EP4492507A1 patent drawingFigure 2A~2B

AI summary

An electrically conductive member includes a first portion and a second portion having a resistivity different from that of the first portion. An electrochemical cell device includes an electrically conductive member and an electrochemical cell connected to the electrically conductive member. The electrochemical cell includes a first part connected to the first portion, and a second part connected to the second portion. A temperature of the first part is higher than a temperature of the second part. A resistivity of the first portion is larger than a resistivity of the second portion.