|The 2011 F-Cell. Click to enlarge.|
Mercedes-Benz, which has begun leasing of the limited production B-Class F-Cell hydrogen fuel cell vehicle (earlier post) in California, is on track to roll out a MY 2015 next-generation B-Class F-Cell in much larger quantities for sale, and is considering introducing a regular sedan-class fuel cell vehicle in around MY 2017, Sascha Simon, Head of Advanced Product Planning at Mercedes-Benz USA, said in an interview with Green Car Congress—perhaps an E-Class version, he suggested.
We are not intending to build a particular fuel cell sub-brand that looks and feels different. Our customers would like to drive our E-Class as a fuel-cell car. It [fuel cell technology] would work beautifully in a regular sedan shape—normal Mercedes luxury, but filled with pressurized hydrogen. I am completely convinced the technology has the potential to take over the internal combustion engine, together with pure battery EVs in their niche.—Sascha Simon
Currently, Mercedes-Benz has 37 leasing customers for the B-Class F-Cell in Southern California, with suggested pricing set at $849 per month for 24 months. Several hydrogen fueling stations are now open in Los Angeles and surrounding areas, including Newport Beach. The F-Cell will become available for Northern California in June.
Although Mercedes-Benz has introduced a plug-in hydrogen fuel cell research vehicle—the F125! (earlier post)—which projects out about 20 years, Simon suggests that a pure fuel cell vehicle could be more price-efficient than a plug-in.
For me it comes down to the price point for batteries versus fuel cells stacks and how this plays out. If you obviously have a price premium for batteries that is not going down over the next ten years, I would argue that a pure fuel cell vehicle is more price efficient versus a plug-in. If you look to the plug-in world right now, the current numbers don’t bode so well. We haven’t see a drop in prices in batteries that we would like to see; we’re monitoring the price point and we’ll take it from there.
I do believe that it is as easy to build a fuel cell car as an ICE [internal combustion engine] car today—and we are almost there—without the need for plug-in capacity. This car [the B-Class F-Cell] is ready for mass production. It drives like a normal car. The HMI is built like a normal car. It’s not not science fiction, not a prototype. They are real-world cars on lease.—Sascha Simon
|“Really now the biggest topic is the available infrastructure. That is really the only hold up there is—there is no other reason why we are not rolling out more of these cars. The new legislation [the Advanced Clean Cars package in California, earlier post] will help very much.”|
B-Class F-Cell. The front-wheel drive B-Class F-CELL offers an operating range of around 240 miles (386 km) on the European driving cycle, or 190 miles (306 km) estimated EPA, and a 3-minute refueling time.
The technical basis for the drive system of the B-Class F-CELL is a second-generation fuel cell stack from Automotive Fuel Cell Cooperation (AFCC)—a Canada-based joint-venture private company between Daimler AG (50.1%), Ford Motor Company (30%) and Ballard Power Systems (19.9% ownership and a financial investor). AFCC serves as a fuel cell center of excellence for the two OEMs. The second-generation stack in the B-Class F-Cell features a power increase from 65 kW to 100 kW, increased lifetime and reliability, and freeze start ability below 0°C.
(In March 2011, Mercedes-Benz announced that it would set up its own production of fuel cell stacks in Vancouver, British Columbia—home of AFCC. Construction of the plant is underway, Simon noted.)
The B-Class F-Cell also features a 1.4 kWh Li-ion battery pack and a compressed hydrogen storage capacity of 3.7 kg at 700 bar. The 136 hp (101 kW) electric motor develops 214 lb-ft (290 N·m) of torque; the B-Class F-CELL uses a single-speed gear reduction transmission w/reverse and recuperation.
The vehicle accelerates from 0-60 mph in 11.4 seconds, and has a top speed of 106 mph (171 km/h). Estimated fuel economy is 52 miles/kg of hydrogen on the city cycle, 53 miles per kg on the highway.
|Progress in fuel cell power density. Source: AFCC 2009. Click to enlarge.|
Next-generation fuel cell work: costs. Overall, Gen 3 fuel cell cars—e.g., the next-gen MY 2015 F-Cell—will demonstrate capabilities competitive with other platforms, but cost remains an issue, according to an AFCC research needs analysis presented in 2009. Accordingly, Generation 3 fuel cell stacks will focus on cost reduction. The Gen 4 stack—which would appear in the sedan application—will also focus on further cost reductions.
There are five basic strategies for cost reduction, AFCC says:
- Less expensive components for balance of plan (BOP);
- Fewer components;
- Less parasitic power loss;
- Less material in the stack itself; and
- Less expensive material in the stack.
|Platinum content reduction and power density. Source: AFCC 2011. Click to enlarge.|
Given the high cost of platinum, new durable, high-activity (and lower-cost) catalysts are critical, AFCC says. Current mature technologies—such as carbon-supported Pt catalysts, current membranes, and current cell and plate designs—have reached their maximum capability, and the Gen 4 stack will utilize them at their maximum. Alternative paths or breakthroughs are needed.
Possible new pathways for cathode catalysts include stabilized platinum alloys; new catalyst-support (non-carbon) interaction (e.g., high surface area metal oxides or core-shell catalysts); pseudo bulk catalysts; and non-precious metal catalysts.
Possible new pathways for membranes include low-cost PFSA membranes; hydrocarbon membranes; or additive technologies—i.e., improving membranes by adding special functional materials.
Automotive Fuel Cells: The Road to Emission Free Mobility (Craig Louie, AFCC, 2011)