On the way to zero emission mobility

Daniel Burtsche

New drive concepts are changing vehicle architecture and placing greater demands on material combinations and lightweight construction solutions.

A 55 percent reduction in greenhouse gas emissions by 2030 compared with 1990 levels and the achievement of climate neutrality by 2050: these are the targets Germany has set itself on the basis of the Paris Climate Agreement. There is no doubt that the transport sector has a major part to play in achieving these goals. 
"Zero emission mobility" is the vision that manufacturers are pursuing in both the passenger and commercial vehicle segments. Which drive technologies will play a decisive role in this? What impact will this have on the vehicle and lightweight construction architecture of tomorrow? Daniel Burtsche, Sales Manager in the 3M Advanced Materials Division, with a focus on automotive and electric mobility, provides answers.

Mr. Burtsche, the automotive industry is undergoing an unprecedented transformation process. "Zero emission" is deeply anchored as a target for OEMs. How can this be achieved?

Through intelligent concepts that meet a wide range of mobility requirements in the best possible way. In my view, no drive technology is likely to be as dominant in the future as the internal combustion engine is at present. Instead, we will see a demand-driven mix of drive systems and vehicle concepts. In other words, the powertrain is differentiating and diversifying. Whether battery-electric drive, hybrid vehicles with conventional or synthetic fuels, the hydrogen-powered fuel cell drive - each technological approach has its justification for certain segments and fields of application.

What development steps and challenges do you see along the way?

A key question is how to find a consensus among the various stakeholders. These include legislators, manufacturers and, of course, the end consumers who use vehicles. In the course of electrification, new players are also added, such as power generators and grid operators. This increases complexity and makes it necessary to bring the various interests into maximum harmony.

And how can this complexity be resolved?

Every technical solution for the powertrain requires individual consideration of its strengths and opportunities, especially in light of the "zero emissions" objective. In the end, it all comes down to an intelligent mix of technologies. In individual passenger transport, the purely battery-electric drive is certainly more justified than in the commercial vehicle sector.

Specifically, in the truck sector, diesel is still the ideal energy storage medium for transporting large masses over long distances. This is precisely why differentiated solutions are needed here, for example with a diesel for long distances and with emission-reduced or emission-free concepts for the last mile in urban environments. The requirement for commercial vehicle manufacturers is to put the right solution on the road for the respective transport job. At the same time, the aim is to develop an emission-free solution across the entire value chain. Electrified drives are an important building block here, but not the only technically possible and target-oriented solution.

Every technical solution for the powertrain requires individual consideration of its strengths and opportunities, especially in light of the "zero emissions" objective. In the end, it all comes down to an intelligent mix of technologies. 

Daniel Burtsche

What strategies are vehicle manufacturers pursuing?

Multi-layered activities and development projects have been underway for some time. Daimler Truck, for example, has set itself the goal of putting a hydrogen-powered vehicle on the road by 2025. At the same time, CEO Martin Daum announced in an interview with the "Stuttgarter Zeitung" that he will no longer use combustion engines for commercial vehicles from 2040 (see Daimler Truck and Cummins to collaborate on medium-duty commercial vehicle engines | Daimler). In the course of this transformation, there will be a densification and concentration. This also means that TIER1 suppliers will reorient and reposition themselves. This in turn will also have an impact on other suppliers and material manufacturers.

How much future does the internal combustion engine still have in this environment?

In the medium planning horizon of 10 to 15 years, the internal combustion engine continues to have its justification, especially in conjunction with synthetic fuels. In the short-term existing vehicle fleets can be optimised in terms of CO₂ with relatively little technical effort. Using the existing infrastructures up to the filling station networks, synthetic fuels can be directly integrated into the existing supply chain. In this way, carbon dioxide emissions from vehicles in emission class Euro 5 and above can be reduced immediately by around 10 percent.

And can the combustion engine itself be further optimised?

Indeed. Even today's highly optimised combustion engines still offer potential. We are familiar with improved sensor technologies, individually controlled camshaft systems and other technical measures to further reduce CO₂ emissions.

The electrified drive, whether purely electric or as a hybrid, adds additional weight to the vehicles in the form of a battery. What does this mean for the layout in vehicle architecture and design?

Battery weight plays a decisive role in the design of electric vehicles in relation to range, size and weight. As a result, the weight shifts upward and the centre of gravity shifts downward. This places high demands on the design of the overall vehicle and requires targeted lightweight design measures. Solutions from 3M can make an important contribution to realising sustainable concepts. 

In the course of lightweight construction development, we are seeing more and more material combinations. Where steel used to meet steel, today aluminium and magnesium or polycarbonate and carbon are increasingly used. This poses major challenges in terms of joining technology, crash behaviour and corrosion properties.
 

What are the main challenges here?

It's about reliable and robust bolted connections, especially on safety-relevant parts such as axle components. How can the axle be fastened to the chassis in the new combination, for example when lightweight materials meet steel? This requires new solutions, such as 3M^TM Friction Shims from, which increase the coefficient of friction in a bolted joint by a factor of 4 to 5. This enables lighter and more compact designs in the vehicle without compromising force and torque transmission. 

What function do the 3M^TM Friction Shims perform?

The friction-enhancing shims serve to secure the bolted connection. In friction-locked connections, the static coefficient of friction influences the transmittable forces and torques. Friction value-increasing measures make it possible to push the limits upwards and thus create reliable, robust connections. The shims consist of a substrate of steel with an electroless nickel coating and diamond particles embedded in it. When the shim is pressed between two components, the diamonds penetrate the mating surfaces and form a microform bond.

In which areas are the shims particularly useful?

In the course of the changes in powertrain and vehicle architecture, I see three central areas of application in particular:

• In optimised combustion engines, installation spaces are being massively reduced, and further increased torques can be observed in the low-end range (low speed). This means an increased effort for robust connection technologies with reduced effective areas.
• Connections between axles and chassis require sophisticated solutions. Whether for wishbones, suspension, crash box, vibration dampers, or the connection of the axle to the chassis - taking into account diverse material combinations.
• The electric motor itself also places high demands on the connection technology, especially since full power is made available immediately. This leads to high forces that act directly on surrounding torsion- or torque-loaded components.

The transformation of the automotive industry on the way to zero-emission mobility is changing not only materials and applications or design, but the entire value chain. In order to achieve the goals set, the players are moving closer together, and new technological partnerships will form in the future.