Hyundai ix35 Fuel Cell hides tech in plain site
BY TIM ROBSON | 15th Apr 2015
Far from being a cobbled-together science experiment, the Hyundai ix35 Fuel Cell is a full-production vehicle for the South Korean brand, and is sold through both its European and American distribution channels.
Hyundai Motor Company Australia (HMCA) is also taking the forward-looking step of establishing its own hydrogen refuelling station to serve its small but growing fleet of fuel-cell-powered cars.
“We are taking a bold step into the future and we hope other Australians become as inspired and excited by this technology as we are,” said HMCA CEO Charlie Kim.
“In February 2013, Hyundai Motor Company became the first automobile manufacturer in the world to begin mass-production of a hydrogen-powered vehicle – the ix35 Fuel Cell. The fact that we have brought one to Australia is testament to how important the Australian market is to Hyundai, and how seriously we take our environmental responsibility.”The ix35 Fuel Cell is a left-hand-drive version of the well-known compact SUV, equipped with a hydrogen fuel tank in the rear, a single electric motor at the front axle and a fuel-cell stack under the bonnet.
Compressed hydrogen is stored in the tank before being pumped to the fuel-cell stack, where it mixes with oxygen drawn in through the front of the car and converted to electricity. This energy then supplies the electric induction motor in real time, producing 100kW and 300Nm to power the front wheels.
The principle behind the process is relatively straightforward. The ix35 uses a PEM (Proton Exchange Membrane or Polymer Electrolyte Membrane) fuel-cell arrangement in a unit that is located under the bonnet.
A fuel-cell has two electrodes – an anode and a cathode – separated by a membrane. Oxygen passes over one electrode and hydrogen over the other.
The hydrogen reacts to a catalyst on the electrode anode that converts the hydrogen gas into negatively charged electrons (e-) and positively charged ions (H +). The electrons then flow out of the cell to be used as electrical energy.
Meanwhile, the hydrogen ions move through the electrolyte membrane to the cathode electrode, where they combine with oxygen to produce heat and water – the only two waste by-products of the process. The heat is dissipated to the surrounding air, while water is emitted as vapour from the vehicle’s tailpipe.
Energy isn’t stored in a battery array as per a conventional electric vehicle.
A small auxiliary battery is carried on board to provide extra boost under full acceleration, and to provide five minutes of running time should the car run out of hydrogen or suffer some sort of fuel-cell failure.
The hydrogen is stored in a small cylindrical tank in the rear of the car. The tank, built from aluminium and encased in carbon-fibre, has met and exceeded every safety standard Hyundai could find.
“The tank is actually shot at while it’s enveloped in fire,” says HMCA product planning manager Scott Nargar. “It’s pretty safe.”The tank in the ix35 holds 5.6kg of compressed hydrogen, with every kilogram representing approximately 100km of vehicle range. All measurements for the fuel are in kilograms, the standard measure for compressed gases, while fuel consumption is based on a speed of 105km/h.
Hyundai claims it can do 0-100km/h in 12.4 seconds, and hit a top speed of 160km/h. Currently, compressed hydrogen costs around $10 a kilogram.
Depending upon the fuelling station used, the ix35’s tank can be refilled in as little as four minutes. This requires the use of a station that pressurises the colourless, odourless gas at 700BAR, or 10,000PSI Hyundai Australia’s compact refueller puts out just half of that, and carries sufficient capacity to refill the car five times before its consumer-spec hydrogen cylinders are depleted.
The gas itself is made via natural gas reformation in Port Kembla, NSW, and is readily and cheaply available across the country, thanks to its wide use in many areas, including the food and beverage industries. It can also be made in small quantities via electrolysis, which is what Hyundai Australia plans to do in the near future. Because its plant will be powered by a solar array, it will be completely carbon-neutral.
Its downsides are its flammability, its ability to spontaneously combust when exposed to air and the fact it burns clear. Hydrogen can also corrode and embrittle metals, so it is requires the use of plastics and carbon-fibre in its piping infrastructures.
It is also a fuel that needs to be manufactured, and its energy density (its bang for buck, in essence) is lower than that of petrol or diesel, so more is required to travel an equivalent distance.
Unlike EVs, fuel-cell vehicle manufacturers have already come to an agreement on the style of fuel coupling that will be used across the industry. It’s as straightforward to use as a petrol bowser, but a lot more intelligent the leading refuelling devices in Europe and the United States chill the gas to speed up fuel transfer, and also note external barometer and temperature readings to ensure a full fuel load is transferred.
In almost every other aspect, the ix35 Fuel Cell mimics its fossil-fuelled brethren the interior packaging (aside from a modified central display screen) is the same and the exterior is unchanged. There is an approximately 400kg weight increase over an equivalent 2WD petrol-powered ix35, though there is also almost 100Nm of extra torque to offset it.
Steering and air-conditioning systems are electrically powered, while the ix35’s brakes are hydraulic (rather than fly-by-wire).
The vehicle is built in South Korea in a US and European spec Hyundai Australia’s vehicle is the latter.
“We order it just like we would order any other car,” said Mr Nargar. “We just preferred the European version – even though the sat-nav is in German!”Mr Nargar also confirmed that more ix35s are on order for use in Australia, and will be delivered before the end of the year.
