Gas Diffusion Body With Thermal Sprayed Coating

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Solution Overview

Problem

Existing gas diffusion bodies in electrochemical cells face challenges such as limited adjustability of pore size, mechanical instability, and long production times, which can lead to membrane rupture and electrode damage under pressure, especially when scaling up.

Innovation Solution

A gas diffusion body is created with an additional layer of powdered electrically conductive material applied using thermal spraying, allowing precise adjustment of pore size and geometry, enhanced mechanical stability, and reduced production time, while eliminating the need for additional connection steps.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If gas diffusion bodies are produced from expanded metal with through-openings, then electrical conductivity is ensured, but the pore size cannot be made arbitrarily small leading to membrane damage risk

Engineering Contradiction:
Improvemembrane integrityVSAvoidpore size control
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent combines expanded metal base layers with a sintered metal powder coating layer to create a composite gas diffusion body. The expanded metal provides electrical conductivity and mechanical strength, while the sintered layer provides fine pore structure for membrane protection. This composite approach resolves the contradiction by integrating two materials with complementary properties.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The gas diffusion body has different pore sizes in different regions: larger through-openings in the expanded metal base layer for water transport, and finer pores in the sintered coating layer for membrane protection. This local differentiation of pore sizes allows each region to perform its specific function optimally without compromising the other.

Inventive Principle:
Principle #3Local quality

2Manufacturing precision

If sintered bodies are used as gas diffusion bodies, then fine pores can be manufactured, but production time is very long due to low heating rates

Engineering Contradiction:
Improvepore sizeVSAvoidproduction time
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

Instead of sintering the entire gas diffusion body (which would require long heating times), the patent applies sintering only to the thin coating layer on the expanded metal base. This partial sintering approach achieves fine pore structure where needed while dramatically reducing production time since the base layer requires no sintering.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The gas diffusion body is segmented into two functionally distinct layers: an expanded metal base layer for structural support and electrical conductivity, and a sintered coating layer for fine pore formation. This segmentation allows each layer to be optimized and manufactured using the most appropriate process for its specific requirements.

Inventive Principle:
Principle #1Segmentation

3Strength

If sintered bodies are used with fine pores, then mechanical stability is improved, but scalability and assembly become difficult due to breakage risk

Engineering Contradiction:
Improvemechanical stabilityVSAvoidscalability
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The sintered layer is applied as a thin coating film on the expanded metal base rather than as a thick standalone component. This thin film approach maintains mechanical stability where needed while minimizing brittleness and breakage risk during handling and assembly, enabling easier scaling to larger dimensions.

Inventive Principle:
Principle #30Flexible shells and thin films

4Reliability

If multiple layers are connected in force-fitting or welding, then gas diffusion body functionality is achieved, but device complexity and production steps increase

Engineering Contradiction:
Improvegas transport functionalityVSAvoidproduction process
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple functions into a single integrated component: the expanded metal base layer and sintered coating layer are applied in one manufacturing process sequence, eliminating the need for separate assembly steps. The coating is applied directly to the base layer in a form-fitting manner, reducing device complexity while maintaining gas transport functionality.

Inventive Principle:
Principle #5Merging (Combining)

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 gas diffusion body with adjustable pore sizes suitable for varying electrolysis pressures, improved mechanical stability, and scalable production, reducing the risk of membrane and electrode damage, and streamlining the manufacturing process.

Implementation Method 1

at least one additional layer which is applied as a powdered material using a thermal spraying process

Methodology Applied
Scientific EffectThermal spraying: Plasma Spray

Data Source

PatentEP3670703A1Gas diffusion body
Publication Date: 2020.06.24 FORSCHUNGSZENTRUM JULICH GMBH
  • EP3670703A1 patent drawingFigure 1
  • EP3670703A1 patent drawingFigure 2
  • EP3670703A1 patent drawing

AI summary

The present invention relates to a gas diffusion body (5) comprising a base layer (7a, 7b, 7c) having at least one through-opening (9) and made of electrically conductive expanded metal, electrically conductive fabric or mesh, or an electrically conductive metal plate provided with through-openings, wherein the gas diffusion body (5) has at least one additional layer (8a, 8b, 8c) applied as a powdered material using a thermal spraying process, wherein the powdered material consists at least largely of particles of electrically conductive material, in particular to a proportion of at least 70 wt.%, preferably to a proportion of at least 90 wt.%.