Schaeffler, a key player in the automotive industry, has taken a substantial leap forward with its groundbreaking metallic bipolar plates designed for Proton Exchange Membrane (PEM) fuel cells.
These plates, often overlooked but crucial to fuel cell systems, represent a significant stride in the development of hydrogen-powered mobility. Schaeffler’s pioneering approach aims to revolutionize fuel cell technology, driving advancements in power density and extending the longevity of fuel cell stacks.
Fuel cell systems are central to the dream of a hydrogen-powered future, and at the heart of these systems lie bipolar plates, responsible for distributing gases, coolant, and removing water generated by chemical reactions. Schaeffler’s innovation takes the form of novel bipolar plates meticulously designed to maximize their surface area. Dr. Jochen Schröder, Schaeffler’s head of E-Mobility, explains, “The finer and more precise the structures on the bipolar plate, the more efficient the plate is.” These meticulously crafted plates pave the way for impressive power density, boasting 4.6 kW per liter of fuel cell volume, including end plates and compression hardware.
In a typical fuel cell stack configuration, numerous bipolar plates are stacked together, each separated by a membrane electrode assembly (MEA). The plates account for a significant portion of the stack’s weight and volume, with stacks consisting of up to 400 cell units capable of delivering power outputs of up to 140 kW, making them suitable for light commercial vehicles. Heavy commercial vehicles, often requiring two stacks, can achieve even higher power levels.
Schaeffler’s commitment to realizing hydrogen-powered mobility extends beyond innovation to industrial-scale production. The company employs a “design for manufacturing” (DFM) approach, optimizing the plates for large-scale production while ensuring cost-effectiveness and scalability. Leveraging its extensive expertise in metal stamping and forming, Schaeffler achieves the precision required to create ultrafine structures on the plate’s surface, with thicknesses ranging from 50 to 100 micrometers.
A key component of Schaeffler’s groundbreaking plates is the Enertect coating system. These high-performance coatings ensure consistent electrical conductivity throughout the fuel cell’s lifespan. The coatings are customizable to meet specific customer requirements, addressing factors such as longevity, environmental impact, and cost-effectiveness. By employing a unique physical vapor deposition (PVD) process, adapted from Schaeffler’s successful history of producing precision components, the coatings ensure unparalleled performance.
To ensure the integrity and safety of fuel cells, Schaeffler employs various sealing techniques. Injection-molded or silk screen gaskets, along with an in-house developed laser welding process, render the fuel cells gas- and watertight. This attention to detail reflects Schaeffler’s commitment to not only performance but also quality and safety.
Schaeffler’s foray into hydrogen-powered mobility signifies a significant milestone in the ongoing pursuit of sustainable transportation solutions. The new generation of metallic bipolar plates promises increased power density and enhanced durability, setting the stage for a future where hydrogen-fueled vehicles play a pivotal role in reducing carbon emissions. By investing in both component-level development and full-scale industrialization, Schaeffler positions itself at the forefront of the hydrogen revolution.
Photo: Schaeffler (Daniel Karmann)
