|Overview and partitioning of the GM-Honda collaboration on fuel cell propulsion. Click to enlarge.|
Over the past two years, GM and Honda have been collaborating on next-generation fuel cell and hydrogen storage systems, aiming at commercialization in the 2020 time frame. (Earlier post.) At the SAE 2015 Hybrid & Electric Vehicle Technologies Symposium in Los Angeles last week, Andrew Bosco, Chief Engineer for fuel cell engineering at GM, provided an progress update on the joint Gen 2 Fuel Cell Propulsion System. (At the SAE 2014 Hybrid & Electric Vehicle Technologies Symposium, Mark Mathias, Director, Fuel Cell R&D for GM, had also provided an update on the collaboration. Earlier post.)
As the two companies have emphasized from the beginning, Bosco reinforced that the current scope of the collaboration focuses on reducing the high cost of fuel cell specific systems: i.e., the fuel cell stack; balance of plant components; and hydrogen storage system (HSS). Development on the battery (regenerative ESS), fuel cell power electronics (FCPE); and electric traction system (ETS) is leveraging know-how and components from hybrids and battery-electric vehicle work.
The two companies are working as “one team” across 3 countries—Japan, US and Germany—Bosco said. The focus is one common system with jointly agreed core and technical targets, capable of 2020 production.
In reviewing the context for the push on fuel cells, Bosco noted that fuel cell electric vehicles, with the travel provision, are the most effective generators of ZEV credits in California and the nine other states that have adopted the California ZEV regulations. FCEVs (350-mile) earn 4 credits in the 2018 and beyond timeframe vs. 1.5 credits for a 100-mile BEV.
|The focus on the GM-Honda work is on reducing costs. For one example, the joint team is targeting a reduction in platinum loading to about 11g Platinum, down from 80g in the Equinox fuel cell. (Earlier post.) Click to enlarge.|
A Pareto analysis of cost shows that many of the expensive parts of the fuel cell system are not entirely unique to fuel cells, Bosco said. The team has reduced the amount of previous metal catalyst required significantly, from 80 g in the Equinox Fuel Cell Vehicle to around 11g in the Gen 2 system. This cost element is no longer a commercial barrier, Bosco said.
On the storage system side, however, the Pareto analysis shows that fiber cost is a major element.
|Fuel cell system cost Pareto. Click to enlarge.||Hydrogen storage system cost Pareto. Click to enlarge.|
One of the examples Bosco touched upon as an example for cost reduction was the bipolar plates themselves in the stack.
Even at low vehicle production volumes, the bipolar plate is a high volume part.—Andrew Bosco
At 300 cells per vehicle, a mere 1,000 vehicles would require 300,000 plates; at 10,000, 3 million, and so on. Global auto production in 2014 was 86.5 million units.
The Gen 1 plates are stamped stainless steel; their cost is sensitive to the price of nickel. The goal is to ￼move away from austenitic stainless steels to ferritic stainless steels, which have low/no nickel. On the plus side, ferritics are magnetic, leading to easier handling. On the downside, formability is a technical challenge.
Overall, Bosco noted, the automotive industry has “extensive cost reduction experience”; suppliers will play a major role in cost reduction opportunities. The partners are looking to deploy the Gen 2 fuel cell technology “early next decade if things keep going the way they are going.”