Illustration of the production process of bipolar foils made of compound material. Copyright: © FEV

Major obstacles to the widespread use of PEM fuel cells in automotive powertrains are the currently still high system and stack costs and their short life time.

The core objective of the project “BiFoilStack” is the development of customized stack concepts for Low Temperature-PEM fuel cells for the target application "commercial vehicle" based on novel compound bipolar foils. These thermoplastic bipolar foils with up to 90 % carbon exhibit high electrical conductivity and low contact resistance, can be adapted precisely to specific requirement profiles and can also be welded with similar joining partners. This opens up completely new design possibilities and thus innovative approaches for new stack concepts.

TME is responsible for the subproject "Electrochemical characterization and evaluation of novel fuel cell stacks based on compound bipolar foils". This includes the detailed electrochemical characterization by means of electrochemical impedance spectroscopy as well as the characterization with regard to the performance of the developed stacks including measurement of the polarization curves and the current density distribution. Another central goal is the lifetime investigation of the novel stacks. For this purpose, accelerated stress tests (AST) are developed, which correspond to the life time requirements of the target application "commercial vehicle". The stacks are then subjected to these ASTs on the test bench in order to demonstrate their service life in operation.

The final objective is to summarize the previously obtained results and to supplement them with further key performance indicators (KPIs). The KPIs should enable a comparison with conventional state-of-the-art metallic bipolar plates.


Development of stack designs for LT-PEM fuel cells with novel compound bipolar foils

Acronym BiFoilStack

Federal Ministry for Economic Affairs and Energy (BMWi)

Term 12/2021 – 11/2024