The BMW Group has commenced fuel cell system production at its competence centre for hydrogen in Munich. By the year-end, a small series of BMW iX5 Hydrogen cars will be entering service around the world for test and demonstration purposes.
“As a versatile energy source, hydrogen has a key role to play on the road to climate neutrality. And it will also gain substantially in importance as far as personal mobility is concerned. We think hydrogen-powered vehicles are ideally placed technologically to fit alongside battery-electric vehicles and complete the electric mobility picture,” said Oliver Zipse, Chairman of the Board of Management of BMW AG, in Munich on Wednesday. “By commencing small-scale production of fuel cells today, we are demonstrating the technical maturity of this type of drive system and underscoring its potential for the future.”
“Our many years of research and development work have enabled us to get the very most out of hydrogen technology,” added Frank Weber, Member of the Board of Management of BMW AG, Development. “We have managed to more than double the fuel cell’s continuous output in the second-generation fuel cell in the BMW iX5 Hydrogen, while weight and size have both decreased drastically.”
High standards of efficiency in the drive system
The BMW Group will now be manufacturing highly efficient fuel cell systems at its in-house competence centre for hydrogen. This technology is one of the core elements in the BMW iX5 Hydrogen and generates a high continuous output of 125 kW/170 hp.
It teams up with an electric motor featuring fifth-generation BMW eDrive technology and a high-performance battery purpose developed for this vehicle to enable its powertrain to deliver 275 kW/374 hp. The development team incorporated the powerful drive system – comprising two hydrogen tanks, the fuel cell and the electric motor – into the existing BMW X5 platform for the small production run. The BMW iX5 Hydrogen already successfully demonstrated its excellent everyday usability, even at very low temperatures, during the final round of winter testing in Sweden at the start of this year.
The impressive testing results of this new small-scale series of cars are rooted in the BMW Group’s extensive experience with the use of hydrogen as a drive technology. Hydrogen-powered combustion engines had already been in use prior to the arrival of the fuel cell system. Efficiency considerations prompted the BMW Group to continue development work in this area from 2015 with the BMW 5 Series GT Hydrogen Cell based on fuel cell technology. Fuel cell technology has since been steadily refined by harnessing the company’s vast know-how in the field of conventional drive technologies and applying the exacting standards of all-round efficiency it expects of all its vehicles.
Production of fuel cell systems
A chemical reaction takes place in the fuel cell between 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 required for manufacturing the BMW iX5 Hydrogen 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. The individual fuel 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 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, the high-voltage coolant pump and the wiring harness.