Fuel Cell Production Spurs Supplier Opportunities

April 1, 2024

Lindsay Brooke

The head of General Motors’ global fuel-cell business is bullish about ongoing opportunities for suppliers in the emerging hydrogen-power space, as GM and partner Honda Motor Co. began series production of their first fuel-cell modules January 24 at a suburban Detroit plant.

The GM-Honda collaboration, launched in 2013, has a growing list of OEM customers for its Hydrotec-branded modules in various power ratings. Included are commercial truck makers Autocar and Navistar and heavy mining and construction equipment maker Komatsu. Honda itself confirmed an initial run of 2,000 lower-power modules for the 2024 CR-V.

“Going forward, we’re always looking for very capable automotive-type suppliers who are willing to bring their know-how,” executive director and veteran engineer Charlie Freese told SAE Media during the Autoline After Hours show . “There should be a lot of overlap with the traditional automotive supply base in where we’re going with this.”

He revealed that the current “Gen-2” Hydrotec supply base is split “almost 50-50 percent” among traditional auto suppliers and newcomers from other industries. Some of the non-traditional players hail from industrial films and coatings – technologies critical for making the cells ’polymeric membranes. In proton-exchange membrane (PEM)-type fuel cells such as Hydrotec, the thin membranes serve as electrolyte, allowing protons to pass to the cathode while restricting the passage of electrons.

Innovations and challenges

More traditional vendors have brought technologies from turbocharging – fuel-cell operation requires pressurized air – as well as technologies proven in diesel aftertreatment. GM and Honda have developed an automotive-inspired stamping process to make the cells’ bi-polar plates with high accuracy, in high volume, “similar to the way we make IC engine cylinder-head gaskets,” Freese said.

Carbon fiber has been an ongoing challenge for automakers to adopt in high volume for mass-produced vehicles due to its high cost and slow cycle times, and Freese noted the supplier universe is small. ”Some companies have done carbon fiber in automotive, but until recently they haven’t been in propulsion systems,” he said. The strong, mass-efficient material plays a vital role in Hydrotec systems, both in the onboard hydrogen storage tanks ’structural integrity and in the cell membranes ’functionality.

“We had to develop the suppliers in that [membrane] space,” he explained. A layer of carbon fiber constitutes part of the electrode membrane that goes into each cell. The layer is made up of hydro-entangled carbon-fiber filaments that change the distribution of the water and gases flowing through the system.

Valve and switching technologies, as well as coolant management overall, are also critical in fuel-cell systems, and new innovations are in demand, Freese said. The valves used in Hydrotec, “deal with a lot of water, but they’re not like those in a typical automotive coolant system. Some are bespoke for the fuel-cell application.” There are also fuel-cell-specific components related to system safety, including pyro switches: “We’re dealing with hydrogen and electricity. In the event of a vehicle crash, we have to be able to discharge all the energy safely and quickly,” Freese asserted. “Pyro switches kind of borrow from airbags, but they’ve never been used in an engine configuration before.”

Automation, simulation keys

Fuel-cell modules also offer new applications for “old tech” such as aluminum casting, used in the stack housing and in the cradles, which resemble IC-engine cradles but are different. “We do development with the supply base” in these areas, Freese said. He predicts that as volume demands rise for fuel-cell power applications, “some of the smaller specialist suppliers will have to be brought into a higher-volume realm – or perhaps some of the larger suppliers will step in.”

GM and Honda engineers developed new manufacturing techniques and approaches to automation that Freese claims enable reductions in fuel-cell cost and increased productivity. For example, the coated membrane film arrives at the 70,000-ft.sq. Brownstown, Michigan, plant in large rolls. Feeding off the roll at a rate of seven meters per minute, the film is automatically scanned to detect any defects at the micron level, Freese explained. It is then cut to length, shaped, and a gasket layer is applied. The membrane then moves into a highly robotized stacker. In 10-second intervals, robots take the elements and build them into the Hydrotec stacks.

The GM-Honda fuel cell development team is co-located with the manufacturing engineers and benefits from a dedicated software-engineering group. “We don’t share the software group –that’s a key advantage for us,” he said. While the Hydrotec team relies on some off-the-shelf simulation and modeling tools, much of the “sim” and modeling toolbox for fuel cells “had to be invented.”

Freese noted that the 400,000-plus hours of testing behind the Hydrotec production launch “is more than any ICE program I’m aware of.”

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