Ceramic Functional Layer Sintering With Coarse Zinc Oxide Aid

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Solution Overview

Problem

Existing methods for producing ceramic functional layers for electrochemical cells require high sintering temperatures and times, often using ultrafine nanopowders that are costly, pose health risks due to dust development, and result in air pollution.

Innovation Solution

A method involving the use of a coarse-grained sintering aid, such as zinc oxide, added to ceramic powder in a mass fraction of less than 0.5%, which is mixed with the ceramic powder to form a paste and applied to a metal-supported substrate, then sintered at temperatures below 1200°C under atmospheric conditions, avoiding the use of ultrafine nanopowders and reducing health and environmental risks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If ultrafine nanopowders are used as sintering aid, then sintering temperature can be reduced, but health risks and air pollution increase due to dust development

Engineering Contradiction:
Improvesintering temperatureVSAvoidhealth risks and air pollution
Core Design Contradiction:
TemperatureVSObject-affected harmful factors

Solution Approach 1:

Instead of using ultrafine nanopowders (high surface area) as sintering aid, the patent inverts the approach by using coarse-grained sintering aid particles with low surface area. This inversion resolves the contradiction by achieving sintering temperature reduction through a different mechanism that does not involve fine particle dust, thereby eliminating health risks and air pollution while still lowering sintering temperature to below 1200°C

Inventive Principle:
Principle #13The other way round (Inversion)

2Reliability

If high sintering temperatures and times are used, then ceramic functional layer quality is maintained, but energy consumption and production costs increase

Engineering Contradiction:
Improveceramic functional layer qualityVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent changes the particle size parameter of the sintering aid from ultrafine/nanopowder to coarse-grained particles. This parameter change enables sintering at lower temperatures (below 1200°C) and shorter times while maintaining ceramic functional layer quality, thereby reducing energy consumption and production costs

Inventive Principle:
Principle #35Parameter changes

3Object-affected harmful factors

If coarse-grained sintering aid is used, then health and environmental risks are reduced, but sintering temperature reduction effect may be diminished

Engineering Contradiction:
Improvehealth and environmental risksVSAvoidsintering temperature reduction effect
Core Design Contradiction:
Object-affected harmful factorsVSTemperature

Solution Approach 1:

The patent optimizes the particle size parameter of the sintering aid to coarse-grained state, which eliminates dust development and health risks. Simultaneously, the chemical composition parameter is optimized (using specific ratios of metal oxides including zinc oxide) to ensure adequate sintering temperature reduction effect is achieved despite the coarser particle size, balancing both requirements

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

This approach lowers sintering temperatures and times, reduces health and environmental hazards, and produces a cost-effective, mechanically and thermomechanically stable ceramic functional layer for electrochemical cells.

Implementation Method 1

a process for producing a ceramic functional layer for an electrochemical cell has already been proposed, in which, in at least one process step, a sintering aid made of a transition metal oxide is added to a ceramic powder... to lower a sintering temperature

Methodology Applied
Scientific EffectSintering: Sintering

Data Source

PatentEP3903373B1Method of forming a ceramic functional layer
Publication Date: 2024.07.24 ROBERT BOSCH GMBH
  • EP3903373B1 patent drawingFigure 1~2
  • EP3903373B1 patent drawingFigure 3

AI summary

The invention relates to a method for producing a ceramic functional layer (12) for an electrochemical cell, in particular for a fuel cell, wherein in at least one method step, a sintering aid (16), consisting of a transition metal oxide, is added to a ceramic powder (14), which forms a primary component of the ceramic functional layer (12), in order to reduce a sintering temperature. According to the invention, the sintering aid (16), which in particular is in coarse granular form, is added to the ceramic powder (14) in at least one method step.