Fuel Cell Sub-Cells with Integrated Current Paths

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Solution Overview

Problem

Conventional fuel cells with bipolar plates face challenges in controlling electrochemical reactions, leading to large undivided reaction surfaces, low stack voltage, and high current, which results in complex and inefficient energy production.

Innovation Solution

The fuel cell design incorporates sub-cells with integrated current paths within the cell stack, eliminating the need for bipolar plates, allowing for targeted current guidance and reducing reaction surface area to control electrochemical processes, thereby increasing stack voltage and reducing electrical resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If cells are divided into sub-cells with integrated current paths, then stack voltage increases and electrical resistance decreases, but device complexity increases

Engineering Contradiction:
Improvestack voltageVSAvoidcell structure complexity
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The fuel cell is divided into multiple sub-cells, each with its own membrane electrode unit and gas diffusion layers. This segmentation allows each sub-cell to function as an independent electrochemical unit while maintaining series connection for voltage accumulation, directly resolving the contradiction by enabling higher voltage without requiring a single large complex structure

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The current paths are integrated directly into the cell structure by making the gas diffusion layers and electrode covers conductive, eliminating the need for separate bipolar plates. This merging of current conduction and gas diffusion functions into single components reduces the number of parts and simplifies the overall device structure while achieving the desired electrical performance

Inventive Principle:
Principle #5Merging (Combining)

2Ease of manufacture

If bipolar plates are used for current conduction, then current paths are established, but manufacturing complexity and cost increase

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidnumber of components
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The gas diffusion layers and electrode covers are designed to serve dual functions: gas transport and current conduction. By making these components electrically conductive through material selection or surface treatment, the patent eliminates the need for separate bipolar plates, directly reducing component count and manufacturing complexity while maintaining current conduction functionality

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

Solution Approach 2:

The bipolar plates are completely removed from the cell structure. Instead of using separate dedicated current-conducting plates, the patent extracts this function and integrates it into the existing gas diffusion layers and electrode covers, thereby simplifying the manufacturing process and reducing the number of parts that need to be assembled

Inventive Principle:
Principle #2Taking out (Extraction)

3Productivity

If large undivided reaction surfaces are used, then cell area is maximized, but electrochemical control becomes difficult and power loss increases

Engineering Contradiction:
Improvereaction efficiencyVSAvoidelectrochemical control complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The reaction surface is divided into multiple smaller sub-reaction surfaces, one in each sub-cell. This segmentation allows for better control of electrochemical reactions in each zone, prevents localized overheating, and enables more uniform current distribution. The divided structure maintains total reaction area while improving controllability and reducing power loss

Inventive Principle:
Principle #1Segmentation

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 design achieves a higher stack voltage with lower current, reducing power loss and enabling smaller, cheaper components, while improving thermal management and gas distribution efficiency.

Implementation Method 1

a membrane-electrode unit - also referred to as MEA - with electrode anode and cathode, anode and cathode catalysts and an electrolyte membrane arranged in between

Methodology Applied
Scientific EffectElectrochemical reaction: Fuel Cell

Implementation Method 2

a cooling and media module as well as associated media lines for oxygen, hydrogen and cooling medium

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP2715847B1Fuel cell without a bipolar plate, having cells divided into sub-cells and having an integrated flow path
Publication Date: 2019.01.16 TEDATEX IND
  • EP2715847B1 patent drawingFigure 1
  • EP2715847B1 patent drawingFigure 1a~1b
  • EP2715847B1 patent drawingFigure 1c~1d

AI summary

The invention relates to a fuel cell, comprising a cell stack (1) having several cells (2, 2') and end plates, but without bipolar plates. In the membrane electrode unit (4), the electrolyte membrane and gas diffusion layers lie between the anode catalyst and the cathode catalyst. A cooling and media module (3, 163, 166) having the media lines for oxygen, hydrogen, and the cooling medium is designed only to provide secondary functional chambers and to form stacks. The electrical conductors are designed as current paths (81) and integrated in the cell stack (1). The cells (2, 2') are divided into one or more stack cells (87, 87') having one or more sub-cells (173, 173'). The fuel cell, which is used to generate electricity, can also be adapted to generate H2 gas and/or O2 gas from water using electricity.