Honda FCX Concept

SLIDESHOW:

Fuel cells will power the cars of the future. We who follow the auto industry hear this quite often, and the vehicles admittedly sometimes seem like a distant pipe dream. But if Honda’s futuristic FCX Concept is any indication, the cars are a lot closer to reality than many might think.

 

A production version closely based on this FCX Concept, first shown on the 2005 auto show circuit, is already confirmed to be headed for limited production, with the first deliveries occurring sometime in calendar year 2008. According to Honda, the 2008 FCX “will be the most advanced and powerful hydrogen fuel-cell passenger car on the planet.”

 

It’s not officially certified for U.S. roads, but the production version to come in 2008 will very closely follow it, both mechanically and cosmetically. Honda currently has only two completely finished and fully functioning FCX Concepts, and as a gesture of their complete confidence in the motoring press, both were brought out to California’s Monterey Peninsula so that, within the confines of Laguna Seca Raceway, we could be allowed some significant seat time behind the wheel.

 

Fuel-cell primer

 

But first, a little fuel-cell primer: The governing concept behind a fuel-cell is that there are two electrode layers separated by a thin proton exchange membrane, together called membrane electrode assembly (MEA) layers. Hydrogen enters from one side, while oxygen enters from the other. Oxygen from the air attracts the hydrogen’s protons, and as the protons pass through the membrane, there are two results: 1) water is formed, and 2) electrons are caught in the membrane and brought through a circuit to create an electrical current. A fuel-cell stack combines hundreds of these cells, basically serving as a giant battery pack comprised of hundreds of cells in series.

 

To simplify even further in case too many notes were being passed during your high-school physics class, a fuel cell is a sort of battery that never needs to be recharged, just fueled with hydrogen. And in such a vehicle, the fuel-cell stacks provide electricity to power what’s essentially otherwise an electric car.

 

Honda has moved very quickly to not only develop a practical fuel-cell vehicle but also to develop the fuel-cell stacks that power it. The automaker was a latecomer to fuel-cell vehicle development (it been researching fuel cells since the late ’80s but didn’t start its vehicle project until 1998, when Daimler-Benz and Toyota already had working models). On an early version of its FCX Honda used its own meticulously assembled fuel-cell stack but later opted to temporarily use a Ballard Power Systems unit that, at the time, offered weight and packaging advantages.

 

“We were still using a Ballard stack in 2002 when we simultaneously delivered vehicles to market in the U.S. and Japan ,” said Sachito Fujimoto, the FCX’s senior chief engineer.

 

Shortly thereafter, in 2003, Honda engineers overcame some of the design hurdles with its second-generation fuel-cell stack. Though less than half the size and weight of the previous stack, the second-gen unit produced significantly more power, more reliably because of a unitized seal system replacing separate seals.

 

Gravity on its side

 

There have been a few tweaks over the past few years to that design, but — again, aside from the car itself — the completely new, third-generation fuel-cell stack is big news. The so-called V Flow FC Stack is a major design departure, with the membrane electrode assembly (MEA) layers aligned vertically, rather than horizontally as in previous versions of Honda’s own fuel-cell stack and the Ballard-supplied one that preceded it. The V Flow unit also goes to a so-called vertebral layout — where all of the systems are aligned along a center tunnel that goes through the stack.

 

Thanks to design advancements, the whole stack now has the dimensions of a small suitcase. Its volume is down to 52 liters, from 66 liters, while the arrangement boasts improved water drainage (thanks to gravity) and a significant improvement in cold-weather startup performance (down to –20 degrees C). The improved water drainage aids cold starts, and heat mass is significantly reduced, so warm up takes a quarter of the time than with the previous stack. Most importantly, the new stack produces 100 kW — 50 percent more power by volume and 67 percent more power by weight compared to the second-generation stack currently used on the current, limited-production FCX.