Electrolyte-Supported SOFC Networking Structure for Lightweight Stacks

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Solution Overview

Problem

Planar solid oxide fuel cells (SOFCs) have low gravimetric power density, making them unsuitable for mobile and aircraft applications due to weight constraints, and existing solutions either suffer from high current losses or manufacturing challenges such as delamination and cracking.

Innovation Solution

An electrolyte-supported fuel cell structure with multiple electrodes in a networking configuration, where a common electrolyte layer provides mechanical support and allows for serial connection of fuel cell segments, reducing the need for heavy interconnectors and enabling suitable sintering temperatures, thus achieving high gravimetric power density and mechanical strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If metallic interconnectors are used to electrically connect cells in planar SOFC stacks, then electrical connection between cells is achieved, but the total weight of the stack increases significantly (interconnectors can take up to 70% of the total weight)

Engineering Contradiction:
Improveelectrical connection between cellsVSAvoidstack weight
Core Design Contradiction:
ReliabilityVSWeight of stationary object

Solution Approach 1:

The patent removes the heavy metallic interconnectors from the fuel cell stack by implementing direct electrical contact between adjacent cells through the common electrolyte layer. The electrolyte itself serves as the electrical connection medium, eliminating the need for separate interconnector components and dramatically reducing stack weight.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The common electrolyte layer performs multiple functions simultaneously: it provides mechanical support for the entire stack, enables electrical connection between adjacent cells, and serves as the ion-conducting medium. This multi-functionality eliminates the need for separate structural and electrical connection components.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Weight of stationary object

If tubular cell designs are used to avoid heavy interconnectors, then stack weight is reduced, but current collection losses increase due to long electron travel distances

Engineering Contradiction:
Improvestack weightVSAvoidcurrent collection losses
Core Design Contradiction:
Weight of stationary objectVSLoss of energy

Solution Approach 1:

The patent transitions from the longitudinal current collection path in tubular designs to an in-plane current collection approach in planar cells. Electrons travel laterally across the electrolyte plane rather than along the length of tubular cells, significantly shortening the current collection path and reducing ohmic losses.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Weight of stationary object

If integrated planar SOFC concepts with porous support substrate are used, then gravimetric power density is improved by avoiding heavy interconnectors, but manufacturing challenges arise including delamination and cracking due to thermal expansion differences

Engineering Contradiction:
Improvestack weightVSAvoidmanufacturing process complexity
Core Design Contradiction:
Weight of stationary objectVSEase of manufacture

Solution Approach 1:

The patent uses a uniform, dense electrolyte layer throughout the stack instead of combining electrolyte with porous support substrate. This homogeneous structure eliminates the interface between dissimilar materials that causes thermal expansion mismatch, preventing delamination and cracking during sintering and operation.

Inventive Principle:
Principle #33Homogeneity

4Weight of stationary object

If multiple fuel cell segments are arranged in a common plane onto a porous support substrate, then gravimetric power density is improved, but sintering temperature constraints arise that can reduce cell performance and durability

Engineering Contradiction:
Improvestack weightVSAvoidcell performance and durability
Core Design Contradiction:
Weight of stationary objectVSReliability

Solution Approach 1:

The patent employs a dense electrolyte layer that can withstand the high sintering temperatures required for electrode formation without degrading. This allows the use of optimal sintering temperatures for the electrodes and interconnectors without compromising the structural integrity of the support layer, thereby maintaining cell performance and durability.

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 results in a lightweight fuel cell structure with short current collection paths and high gravimetric power density, while simplifying the manufacturing process and enhancing mechanical stability, reducing weight and manufacturing challenges.

Implementation Method 1

an oxide conducting ceramic electrolyte

Methodology Applied
Scientific EffectIon conduction: Conduction (electrical)

Implementation Method 2

planar solid oxide fuel cells (SOFCs)

Methodology Applied
Scientific EffectFuel cell electrochemical reaction: Fuel Cell

Data Source

PatentEP4340081A1Networking electrolyte supported fuel cell structure
Publication Date: 2024.03.20 AIRBUS OPERATIONS GMBH
  • EP4340081A1 patent drawingFigure 1
  • EP4340081A1 patent drawingFigure 2~3
  • EP4340081A1 patent drawingFigure 4~5

AI summary

An electrolyte-supported fuel cell structure (100) is provided. The fuel cell structure (100) comprises an anode layer (110) having a first anode (111) and a second anode (112) electrically isolated from each other, a cathode layer (120) having a first cathode (121) and a second cathode (122) electrically isolated from each other, and a common electrolyte layer (130), arranged between the anode layer (110) and the cathode layer (120). The anode layer (110), the cathode layer (120) and the electrolyte layer (130) each extend in a first direction (101) and a second direction (102). The electrolyte layer (130) comprises a row (131) of through holes (132) aligned in the first direction (101) of the fuel cell (100) and is a continuous layer, so as to provide mechanical support for the fuel cell structure (100). The first anode (111) and the first cathode (121) define a first fuel cell segment (140). The second anode (112) and the second cathode (122) define a second fuel cell segment (150). The first cathode (121) is electrically interconnected with the second anode (112) through at least some of the through holes (132), so as to establish a serial connection between the first fuel cell segment (140) and the second fuel cell segment (150). Flat, square tubular, cylindrical tubular, and monolithic structures for the fuel cell structure (100) are disclosed.