Japan's oldest automaker, Daihatsu, raised some eyebrows a couple of years ago when it unveiled its FC ShoCase vehicle. Along with being funny-looking, it was powered by a prototype fuel cell (first announced in 2007) that was said to overcome some of the key limitations of traditional hydrogen fuel cells. At this year's Tokyo Motor Show, a new FC concept vehicle has been presented – the FC Deco Deck mini-truck.
A detailed description of the fuel cell can be found in our previous article on the ShoCase, but here's an overview of what makes it special ...
In a conventional fuel cell, platinum must be used as the electrode catalyst, as its excellent corrosion-resistance keeps it from being eaten away by the cell's acidic polymer electrolyte membrane. Daihatsu's cell, by contrast, utilizes a much more innocuous alkaline anion exchange membrane. This means that expensive platinum isn't required for the electrode catalyst, which can instead be made from cheaper metals such as nickel or cobalt.
Also, instead of hydrogen, the new cell uses hydrazine-hydrate (hydrogen and nitrogen) as fuel. It is claimed to offer a high power density similar to that of hydrogen, and since it's a liquid, it's easier to handle.
Along with utilizing an anion exchange fuel cell as its own source of power, the FC Deco Deck also features one in its compact, "low-cost" onboard generator. This could allow the vehicle to supply power in emergencies, or at remote locations. Daihatsu has additionally created two stand-alone versions of that generator, which are on display with the mini-truck.
The automaker is also using this year's show to introduce its non-fuel cell Deca Deca concept. Its big selling point is interior space, augmented by seats that can fold completely flat, and double doors on both sides that allow for easy loading of cargo. It also features high seating, giving drivers a commanding view of the road.
Source: Daihatsu
FYI: Hydrazine is highly toxic and dangerously unstable, especially in the anhydrous form. According to the U.S. Environmental Protection Agency:
Symptoms of acute (short-term) exposure to high levels of hydrazine may include irritation of the eyes, nose, and throat, dizziness, headache, nausea, pulmonary edema, seizures, coma in humans. Acute exposure can also damage the liver, kidneys, and central nervous system. The liquid is corrosive and may produce dermatitis from skin contact in humans and animals. Effects to the lungs, liver, spleen, and thyroid have been reported in animals chronically exposed to hydrazine via inhalation. Increased incidences of lung, nasal cavity, and liver tumors have been observed in rodents exposed to hydrazine.
Limit tests for hydrazine in pharmaceuticals suggest that it should be in the low ppm range. Hydrazine may also cause steatosis. At least one human is known to have died, after 6 months of sublethal exposure to hydrazine hydrate.
On February 21, 2008, the United States government destroyed the disabled spy satellite USA 193 with a sea-launched missile, reportedly due to the potential danger of a hydrazine release if it re-entered the Earth's atmosphere intact.
I like the idea of the fuel cell vehicle. I think it would be better if it just used hydrogen since it is very plentiful.
I think it is a neat design.
Hydrazine hydrate is the reason this type of fuel cell does not need platinum, if it used hydrogen on its own it would need platinum. I believe it was the Italians who first proposed this idea.
Hydrazine has a lot of benefits. Cheaper engines, just as good sometimes better electricity, safe compound when stored. But we would need to see if they actually store it as hydrazone, or another compound, and how they manage the refuelling.
Toyota should pick it up and run with it.