Fuel Cell Silicate Oxidation Suppression Layer

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Solution Overview

Problem

Fuel cells face oxidation and damage issues due to zirconia's oxygen ion conductivity and thermal expansion coefficient differences, leading to potential damage from backflow and thermal stress.

Innovation Solution

A fuel cell design featuring a columnar conductive support substrate with a silicate-based oxidation suppression layer, containing elements from Group 2 of the periodic table, which is applied to the non-power-generation portion without an air electrode layer, and chamfered corners to alleviate thermal stress, enhancing thermal expansion matching and structural integrity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If zirconia is used to cover one end of the fuel cell to prevent backflow damage, then protection against backflow is improved, but oxidation of the fuel cell occurs due to oxygen ion conductivity

Engineering Contradiction:

Improvebackflow damage protectionVSAvoidoxidation

Core Design Contradiction:

Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

The patent introduces an intermediary layer (oxidation suppression layer) composed of silicate containing Group 2 elements between the zirconia cover and the fuel cell components. This intermediary layer blocks the oxygen ion conductivity pathway that causes oxidation while maintaining the physical barrier function against backflow, thus resolving the contradiction between protection and oxidation prevention

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent employs a composite material structure combining silicate with Group 2 elements (such as magnesium or calcium) to create the oxidation suppression layer. This composite material provides both mechanical protection and chemical stability, preventing oxidation while maintaining structural integrity at the fuel cell end

Inventive Principle:

Principle #40Composite materials

2Object-affected harmful factors

If alumina is used to cover one end of the fuel cell, then protection against backflow is improved, but thermal expansion damage occurs due to coefficient difference

Engineering Contradiction:

Improvebackflow damage protectionVSAvoidthermal expansion resistance

Core Design Contradiction:

Object-affected harmful factorsVSStrength

Solution Approach 1:

The patent changes the material parameter (thermal expansion coefficient) by selecting silicate containing Group 2 elements that have thermal expansion characteristics matching the fuel cell components. This parameter matching reduces thermal stress during temperature cycling while maintaining the protective function against backflow

Inventive Principle:

Principle #35Parameter changes

3Reliability

If zirconia is applied to one end of the fuel cell, then oxidation protection is attempted, but manufacturing complexity increases due to additional processing steps

Engineering Contradiction:

Improveoxidation suppressionVSAvoidmanufacturing process simplicity

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The oxidation suppression layer is formed as a preliminary step before assembling the final fuel cell structure. By preparing this protective layer in advance on the conductive support substrate, the manufacturing process becomes more streamlined, and the oxidation protection is built-in rather than added as a separate complex assembly step

Inventive Principle:

Principle #10Preliminary action

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 suppresses oxidation and thermal damage, improving the reliability of the fuel cell by preventing backflow-induced oxidation and reducing thermal stress concentrations, thus enhancing the fuel cell's durability and performance.

Implementation Method 1

since zirconia has oxygen ion conductivity, there is the possibility of oxidation of one end of the fuel cell

Methodology Applied

Scientific EffectOxygen ion conductivity: Conduction (electrical)

Implementation Method 2

in the case of covering one end of a fuel cell with alumina, there is the possibility that the fuel cell sustains damage caused by the difference in thermal expansion coefficient

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP2355217B1Fuel battery cell, fuel battery module, fuel battery device and method for manufacturing fuel battery cell

Publication Date: 2016.10.26 KYOCERA CORP

Figure 1
Figure 2(a)~2(b)
Figure 3~4

AI summary

There are provided a fuel cell capable of suppressing damage to an end thereof, and a fuel cell module and a fuel cell device that include the fuel cell. In a fuel cell (1) wherein a fuel electrode layer (3) is formed on one of opposite main surfaces of a solid electrolyte layer (4) and an air electrode layer (5) is formed on the other of the main surfaces, and electric power is generated by utilizing a fuel gas and an oxygen-containing gas, an oxidation suppression layer (10) is located closer to the fuel electrode layer (3) than at least the solid electrolyte layer (4) on one end of the fuel cell (1), the oxidation suppression layer (10) being composed mainly of silicate containing at least one of elements belonging to Group 2 on the periodic table. This makes it possible to provide a fuel cell (1a) capable of suppressing damage to and oxidation of one end thereof.