BMW iX5 Hydrogen vehicle development enters critical next phase

After four years of development work, the BMW iX5 Hydrogen vehicle and development project is entering its critical next phase. On February 27, the BMW Group presented to international media representatives the first vehicles in a pilot fleet that will go into service  this year.

“Hydrogen is a versatile energy source that has a key role to play in the energy transition process and therefore in climate protection. After all, it is  one of the most efficient ways of storing and transporting renewable  energies,” said Oliver Zipse, chairman of the Board of Management of BMW AG. 

“We should use this potential to also accelerate the transformation of the  mobility sector. Hydrogen is the missing piece in the jigsaw when it comes to  emission-free mobility. One technology on its own will not be enough to  enable climate-neutral mobility worldwide,” he said.

The BMW iX5 Hydrogen, which was developed on the basis of the current BMW X5, was  first unveiled as a concept at the IAA show in 2019. Initial prototypes were  then made available at the IAA Mobility 2021 for visitors to experience in  action as shuttle vehicles.  

The BMW  Group is systematically pushing forward with the development of hydrogen fuel  cell technology as an additional option for locally emission-free individual  mobility in the future. According to BMW, its hydrogen fuel cell system is further proof that it is leading development expertise in the field of electric drive technologies.

The fleet of under 100 vehicles will be employed internationally for  demonstration and trial purposes for various target groups. This active driving  experience will therefore be the first chance for people not involved in the  development process to gain a direct impression of what the BMW iX5  Hydrogen has to offer.  

The BMW Group produces the highly efficient fuel cell systems for the pilot  fleet at its in-house competence centre for hydrogen in Munich, Germany. This  technology is one of the core elements in the BMW iX5 Hydrogen and  generates a high continuous output of 125 kW/170 hp.  

A chemical reaction takes place in the fuel cell between gaseous hydrogen  from the tanks and oxygen from the air. Maintaining a steady supply of both  elements to the fuel cell’s membrane is of crucial importance for the drive  system’s efficiency. In addition to the technological equivalents of features  found on combustion engines, such as charge air coolers, air filters, control  units and sensors, the BMW Group also developed special hydrogen  components for its new fuel cell system. These include the high-speed  compressor with turbine and high-voltage coolant pump, for instance.  

The BMW Group sources the individual fuel cells from the Toyota Motor  Corporation. The two companies have enjoyed a partnership characterised by  trust for many years and have been collaborating on fuel cell drive systems since 2013.  

Fuel cell systems are manufactured in two main steps, based on the individual  fuel cells. The cells are first assembled into a fuel cell stack. The next step  involves fitting all the other components to produce a complete fuel cell  system.  

Stacking of the fuel cells is largely a fully automated process. Once the individual components have been inspected for any damage, the stack is  compressed by machine with a force of five tonnes and placed in a housing.  The stack housing is manufactured in the light metal foundry at BMW Group Plant Landshut using a sand casting technique.  

For this, molten aluminium is poured into a mould made from compacted sand  mixed with resin in a process specially designed for this small-series vehicle.  The pressure plate, which delivers hydrogen and oxygen to the fuel cell stack,  is made from cast plastic parts and light-alloy castings, also from the  Landshut plant. The pressure plate forms a gas-tight and water-tight seal  around the stack housing.  

Final assembly of the fuel cell stacks includes a voltage test along with  extensive testing of the chemical reaction within the cells. Finally, all the  different components are fitted together in the assembly area to produce the  complete system.  

During this system assembly stage, further components are fitted, such as the  compressor, the anode and cathode of the fuel-cell system, the high-voltage  coolant pump and the wiring harness.  

In combination with a highly integrated drive unit using fifth-generation BMW  eDrive technology (the electric motor, transmission and power electronics are  grouped together in a compact housing) at the rear axle and a power battery with lithium-ion technology developed specially for this vehicle, the  powertrain channels maximum output of 295kW/401 hp onto the road. In  coasting overrun and braking phases, the motor also serves as a generator,  feeding energy back into a power battery.  

The BMW iX5 Hydrogen is being built in the BMW Group’s pilot plant at its  Research and Innovation Centre (FIZ) in Munich. This is the interface between  development and production where every new model from the company’s  brands is made for the first time. Around 900 people work there in the body  shop, assembly, model engineering, concept vehicle construction and additive  manufacturing.  

They are tasked with ensuring that both the product and the manufacturing  process are ready for series production. In the case of the BMW iX5  Hydrogen, specialists in hydrogen technology, vehicle development and initial  assembly of new models have been working closely together to integrate the  cutting-edge drive and energy storage technology.