Developed the basis for the fuel cell vehicle since 1992. In 2015, the first production vehicle Mirai appeared, an interesting vehicle concept for the 21st century. With a new fuel cell technology and a new design, Toyota wants to get the public excited about the new Mirai. So far, cars with fuel cell drives are still a niche, Toyota is aiming for higher sales figures in the future.
While electric cars in Europe are growing significantly from year to year, the market for fuel cell vehicles is consistently low. A thin network of hydrogen filling stations, high new car prices and so far low acceptance are important reasons for the reluctance to buy. Only a few vehicles from this segment are usually only offered to order. The new Toyota Mirai comes with more effective fuel cell technology, a new floor plan and a more appealing design.
All current fuel cell cars hardly achieve more range than a modern electric car, and so, according to Toyota, the first thing to do is to increase the range significantly. In the new Mirai generation, engine power, the capacity of the hydrogen tanks and aerodynamics have been revised for this purpose. In the end, the radius of action is said to have been increased by 30% compared to the current Mirai and, according to the manufacturer, is around 650 kilometers. This means that long distances can also be driven in a relaxed manner.
Modular GA-L platform as a basis
The basis for the Mirai is the TNGA-L platform (TNGA - Toyota New Global Architecture). This means that the fuel cell unit moves under the hood, or should we say fuel cell hood from now on? The biggest advantage is definitely the gain for the interior, it now finally offers space for five people. With the new platform, the wheelbase has increased by another 14 centimeters to an impressive 2,92 m, while the vehicle height has been reduced by another 6,5 centimeters to 1,47 m. A wider track and larger wheels with 19 or 20 inch rim diameters make it look like an imposing sports coupe.
The range increase is also related to the new GA-L platform. With three instead of two high-pressure hydrogen tanks, the Mirai can expand the total capacity to 5,6 kilograms of hydrogen. The tanks are located under the vehicle floor and trunk and thus also ensure a low center of gravity. The compact high-voltage battery and the electric motor are mounted above the rear axle. The weight distribution is optimized to 50% each on the front and rear axles.
Compact fuel cell stack
According to Toyota, all components, including water pumps, intercoolers, air conditioners, compressors and hydrogen recirculation, are now combined within the framework of the fuel cell network. The battery pack consists of 330 cells with a specific power density of 5,4 kW per liter. The cell can now be started at temperatures down to minus 30 degrees Celsius.
“The fuel cell unit also includes a DC-DC converter (direct current-direct current) and modular high-voltage components. Thanks to state-of-the-art technologies, they are 21 percent smaller than the current system, while the weight has been reduced by 2,9 to 25,5 kilograms. For the transistors of the Intelligent Power Modules (IPM), Toyota is using the next generation of silicon carbide semiconductors for the first time. This improves the power output, although fewer transistors are used and the power loss is less. Conversely, this means that the entire FCPC fuel cell converter can be made smaller. "(Source: Toyota)
So far, Toyota has relied on nickel-metal hydride batteries; a lithium-ion battery with a capacity of 4,0 Ah is installed in the new Mirai. The more compact battery sits behind the rear seat bench. For the chassis, the Mirai now uses more comfortable multi-link wheel suspensions at the front and rear.
According to the manufacturer, a filter developed by Toyota, which works according to the catalytic converter principle, is supposed to filter out microscopic particles from the air - including sulfur dioxide (SO2), nitrogen oxides (NOx) and PM-2,5 nanoparticles. Apparently 90 to 100 percent of all particles with a diameter between zero and 2,5 micrometers that flow through the intake tract are supposed to be caught in the filter. From our point of view, the question still arises as to how these filters are recycled.
Fuel cells in cars - quo vadis?
While the installation of fuel cells in the truck sector will become a market of the future by 2030, the question arises for cars as to whether this technology will catch on. Toyota wants to reduce the selling price of the 2nd generation by 20% compared to the previous model. It remains to be seen whether the tenfold increase in deliveries forecast by Toyota will be possible.
There are currently a few hundred hydrogen filling stations around the world. According to announcements, more than 2030 filling stations are to be built in the important markets by 5.000. At the moment there are only a few countries with ambitious plans for hydrogen-based mobility. These include, for example, Korea with a targeted 1,8 million vehicles or China and California with one million vehicles each expected by 2030.
Cooperation with BMW
BMW and Toyota have been working together on fuel cell drives since 2013, and they are also jointly developing a sports car. The sports car, released as the Toyota Supra and the BMW Z4, is produced by Magna Steyr in Graz. With the fuel cell, Oliver Zipse wants to extend the cooperation beyond 2025, he told Automobilwoche. In addition, both partners want to bring a series of the model X5 with fuel cell drive on the market. "I now think for the next few decades that we would do well to further promote and strengthen this bonding", is the official statement from BMW boss Oliver Zipse to the Automobilwoche.
Cover picture - New Toyota Mirai - Copyright Toyota
There are more trends and current tests in the new magazine. Subscription under