The drive and fuel strategy is paving the way to carbon-neutral and sustainable mobility. Our focus – and part of our responsibility as a group – is to increase the efficiency of every drive with each new generation, that is to say the efficiency of combustion engines, hybrids and plug-in hybrids, wholly electric vehicles and, in future, potentially that of fuel cells. The range of drive types will increase significantly. But what is the key to a breakthrough where sustainable mobility concepts are concerned? Without a doubt, the focus is on the customers and their increasingly individualised needs. For the customers have to accept the new technologies and be prepared to pay an appropriate price for them. To ensure we can always offer them the right solution, the way forward is to allow “traditional” drives and electric mobility to exist side by side.
As a global manufacturer in a market where the conditions and amount of funding available vary enormously from country to country, Volkswagen is working on providing each and every customer with exactly the kind of mobility they require – whilst also becoming the number one in terms of environmentally-friendly technology.
Natural gas vehicles play an important role in the range of drive types. The chemical properties of the fuel alone mean that they emit some 25 % less CO2 than petrol-driven vehicles, and customers experience this in vehicles ranging from the eco up! to the A3 g-tron. Where traditional drives are concerned, both the launch of BlueMotion technology in TDI and TSI engines and lightweight designs, engine management systems and aerodynamics, in conjunction with the dual clutch gearbox, have already significantly lowered consumption – by 30 % since 2000. And the vehicles are also becoming more and more economical with each new generation.
In addition to the traditional drives, there are the fully electric vehicles like the e-up! and the e-Golf, which are emission-free to run and are particularly suited to customers who make short journeys in urban areas on a day-to-day basis. As well as being able to charge the battery at home using a wall box, for example, there needs to be the option of a good, public charging infrastructure in the medium to long term. Hybrids and plug-in hybrids offer the best of both worlds – plug-in hybrids, for example, combine a highly efficient combustion engine with an electric range of some 50 kilometres. Volkswagen sees great opportunities in this combination of drive concepts: offering our customers in all vehicle classes electrification that is equally suitable for long and short haul; creating confidence in the new technology; and helping electric mobility to break through.
“The focus is on the customers and their increasingly individualised needs.”
Like vehicle concepts, the drive concept is about finding the best technical solutions in order to satisfy the competing requirements of performance, efficiency, customer benefit and costs.
Research focuses primarily on discovering the physical potential and limits of individual components, such as the combustion engine, electric drive motor, gearbox, battery and fuel cell, in a bid to find an overall concept that is technically feasible for the period up to 2030.
The focus is very much on increasing efficiency, reducing CO2 emissions and identifying technology that is compatible with sustainable energy sources. Research projects on drive concepts look at a range of different topologies, ranging from combustion engine-based hybrid concepts and plug-in hybrid systems all the way to full battery and fuel cell-based electric drive systems.
Using simulation systems and different design methods, engineers create vehicle-specific drafts for alternative drive concepts which are then incorporated into presentation prototypes using new operating and control strategies.
One of the biggest areas of potential is the efficient application of each individual component’s technical capabilities in conjunction with a blend of electrical and mechanical components in the overall drive train system.
These solutions can be applied in a wide array of vehicles, from small and mid-range cars to luxury class and sports vehicles. The physical interconnections and basic technology form the foundation for integrating the drive concepts into light, medium and heavy commercial vehicles with a wide selection of driving modes and user profiles.
Combustion engines continue to play an essential role in long-distance individual mobility, primarily due to the fact that they are becoming increasingly environmentally friendly and economical. At the same time, customers still want the same level of driving dynamics and comfort they have come to expect. Volkswagen is conducting in-depth research into combustion engines using innovative diesel, petrol and gas combustion processes. These processes apply cutting-edge exhaust gas treatment solutions, thermal management systems, engine management systems and hybrid systems in a bid to use energy as efficiently as possible while still providing good driving dynamics and adhering to future emissions requirements. New materials and design methods are also applied to help reduce friction in the drive train and reduce its weight.
When approaching this wide array of tasks, developers apply special development methods and tools for calculation, simulation, test planning and data analysis. In doing so, they are hoping to study complex interaction between individual components in more detail and at a more extensive scale so that they are able to improve hybrid drive systems for the long-term, making them ready to tackle the challenges arising in years to come.
“In doing so, they are hoping to study complex interaction between individual components in more detail and at a more extensive scale so that they are able to improve hybrid drive systems for the long-term, making them ready to tackle the challenges arising in years to come.”
Volkswagen is also conducting in-depth research into electrical solutions for the drive system, a focal point of which is the battery system.
When it comes to batteries, developers require a comprehensive understanding of cellular chemistry to be able to analyse issues such as service life, intrinsic safety, energy density, power density, response to temperature and costs. They examine a wide range of battery cells and their chemical composition in order to determine their suitability for electrical drive systems. Research into battery cells also involves examining, enhancing and analysing the potential of existing li-ion cells and their material, studying future solutions such as solid electrolyte cells, and developing an ageing model based on physical properties.
In order to evaluate battery cells and cell materials, Volkswagen also develops, applies and standardises analysis methods. These methods include determining electrochemical characteristics on the test bed, opening cells and analysing the chemical processes in individual cell components.
Impedance spectroscopy, raman spectroscopy, ion and gas chromatography, and optical emissions spectrometry are all good examples of the methods used by our developers.
One of the biggest challenges we face is finding ways to integrate batteries into the overall vehicle architecture. Volkswagen is therefore conducting research into battery systems so that battery cells can be incorporated into new vehicle concepts as cost-efficiently as possible and taking up as little space and weight as possible, while still providing a high level of safety. This involves looking at new cell formats and new electrical components for constructing battery systems. Reliable thermal management plays an important role when it comes to developing new battery concepts for high-powered and high-performance applications.
Volkswagen is also conducting in-depth research into electrical solutions for the drive system, a focal point of which is the continuous development of the battery system. One challenge which refuses to go away is the issue of charging time.
The fuelling times of just 2 to 3 minutes offered by petrol or diesel engines are simply not possible for battery-powered electric cars. This is why fuel cells represent such an interesting prospect. They use hydrogen which is stored in tanks like those used for natural gas, and offer a range of around 500 km in HyMotion models.
Fuel cells use hydrogen from the vehicle’s tanks and oxygen from the air outside the vehicle. Using platinum as a catalyst, the two substances undergo an electrochemical reaction, releasing current for the electric motor. The only “emission” produced is pure evaporated water.
Over the longer term, fuel cells could be a further alternative for electric mobility. After all, a fuel cell battery vehicle is simply another form of electric mobility.
In 2014, fourth generation HyMotion4 fuel cell vehicles were showcased at the motor show in Los Angeles.
Fuel cell systems are undergoing constant development in our research department. Reducing the level of precious metal loading is one of the main focuses of our work. In order to reduce the amount of platinum, our engineers require an in-depth understanding of ageing mechanisms.
We use this knowledge to improve all components within the system so that we can create a strong and cost-efficient fuel cell system.
“Over the longer term, fuel cells could be a further alternative for electric mobility.”
Sources of fuel
Green mobility that conserves our planet's resources is an important component of Volkswagen's approach to corporate responsibility. We want our vehicles to be CO2 neutral. Due to the fact that we can only reduce the fuel consumption of our combustion engines to a limited extent, renewable fuels play an important role in our work.
That is why Volkswagen assesses renewable fuels, their production processes and their requirements for future infrastructure. We calculate the potential and cost of future renewable fuels and translate these into energy scenarios. We compare the efficiency of various drive solutions, looking at how the fuel is produced, while also evaluating the relevant storage technologies (e.g. power-to-gas, hydrogen).
Our findings from these scenarios and forecasts are incorporated into the Volkswagen drive and fuel strategy.
Volkswagen Group Research is responsible for studying the feasibility of this matter and not its use as standard equipment. The use in vehicle production is not currently planned at this time.