Elastic Bipolar Plate Structure for Fuel Cell Stack Compression

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing bipolar plates in fuel cells face constraints due to the need for precise matching of half-plates, leading to reduced design flexibility and issues with compression springs causing uneven stack compaction and potential damage, while also requiring additional components like compression springs and clamping devices.

Innovation Solution

The use of elastic structural elements between the anode and cathode plates, made of materials like conductive polymers or carbon-based materials, which act as embedded springs to optimize compression and structural robustness, eliminating the need for compression springs and allowing for reduced stacking height and weight savings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional flow field plates with grooves are used, then water removal is achieved, but manufacturing precision deteriorates due to difficult groove formation and sealing issues

Engineering Contradiction:
Improvewater removal capabilityVSAvoidgroove formation precision
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The flow field plate is divided into multiple platelets stacked together. Each platelet has simplified structures with protrusions and recesses that form flow channels when stacked, eliminating the need for complex groove machining on single plates while maintaining water removal capability through the segmented architecture.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention transitions from two-dimensional groove patterns on flat plates to three-dimensional stacked platelet structures. Flow channels are formed by the interaction of protrusions and recesses across multiple stacking layers, adding a vertical dimension that simplifies manufacturing while preserving fluid distribution and water removal functions.

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

2Temperature

If cooling channels are added to flow field plates, then heat dissipation is improved, but device complexity increases

Engineering Contradiction:
Improveheat dissipationVSAvoidflow channel structure complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The stacked platelet structure serves multiple functions simultaneously: it creates flow channels for reactant distribution, provides cooling channels for heat dissipation, and enables water removal. The same three-dimensional protrusion-recess architecture that forms flow channels also defines cooling pathways, eliminating the need for separate cooling structures.

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

Solution Approach 2:

The invention merges the flow channel function and cooling channel function into a single integrated stacked platelet structure. Cooling channels are formed by the same stacking mechanism that creates flow channels, combining thermal management and fluid distribution into one unified structure rather than separate components.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If sealing structures are added to prevent leakage, then reliability is improved, but manufacturing complexity increases

Engineering Contradiction:
Improveleakage preventionVSAvoidsealing structure fabrication
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The sealing function is achieved through the self-complementary geometry of the stacked platelets. The protrusions of one platelet fit into the recesses of adjacent platelets, creating inherent mechanical interlocking and sealing without requiring additional sealing components. The structure seals itself through its own geometric configuration during assembly.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The sealing structure is merged with the flow channel structure itself. The same protrusions and recesses that define the flow pathways also provide the sealing mechanism, eliminating the need for separate sealing elements and simplifying manufacturing while ensuring leakage prevention.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3953986B1Bipolar plate for fuel cells, fuel cell stack with such bipolar plates as well as vehicle with such a fuel cell stack
Publication Date: 2026.05.06 AUDI AG
  • EP3953986B1 patent drawingFigure 1
  • EP3953986B1 patent drawingFigure 2~3
  • EP3953986B1 patent drawingFigure 4~5

AI summary

The invention relates to a flow field plate for a fuel cell, which has an anode plate (30) with an anode side (31) and a coolant side (32), a first structure (33) being formed on the anode side (31) to form an anode flow field (34), and a cathode plate (40) with a cathode side (41) and a coolant side (42), a second structure (43) being formed on the cathode side (41) to form a cathode flow field (44), wherein structure elements (51) are arranged between the anode plate (30) and the cathode plate (40) to form a coolant flow field (50), said structure elements being in contact with the coolant sides (32, 42) of the anode plate (30) and the cathode plate (40). Said flow field plate has an optimised pressure distribution in a fuel cell stack (100) and greater stability than the prior art because, according to the invention, the structural elements consist of an elastic material. The invention further relates to a fuel cell stack and a vehicle.