The benefits of renewable energy sources such as water, wind and solar power are well known, and electric cars are not a new concept. However, to reduce our dependence on fossil fuels, which will be exhausted in just one century, efficient ways of mass producing the cells need to be established.
The electric motor can be up to four times more efficient than the combustion engine. Given the finite nature of fossil fuels, the uptake of electric cars or emobility as it is now called is inevitable. However, what does this mean for automation technology? Steve Sands, Product Manager at Festo GB, reviews the current situation.
Fossil fuels are expected to be depleted by 2112 and a report by WWF says that in Great Britain one in 17 cars by 2020, and one in six by 2030, must be electric if they are to meet emission targets and bring an end to a dependence on oil. This means that 1.7 million electric vehicles will need to be put on the road by 2020 and then treble take-up of the technology in the following decade if it is to meet its climate change targets.
However, there were only 1,052 claims on the British government electric car subsidy in 2011 and one of the barriers to the adoption of electric vehicles is their cost. Despite government grants the vehicles are still expensive, constrained in supply and there are too many good conventional alternatives.
For electric cars to compete against Britain’s fleet of 31m fossil fuel cars they need to be more affordable. Consumers will only accept emobility suitable for daily use when the batteries allow a sufficient distance to be travelled and their cost does not increase the vehicle price compared with an equivalent petrol or diesel model.
Currently between 30 and 40 per cent of the cost of electric vehicles is down to the battery. Battery production manufacturing costs are high and there is a lot of research into alternative materials and processes. For now, one way to reduce cell costs is through increasing efficiency in automation.
The problem is that battery lithium-ion production is still predominately a manual process with a large number of individual steps. During the battery manufacturing process, two battery cells are bonded by a foil. Each cell is bonded to a copper plate and several double cells are combined to form a battery pack. With conventional automation processes the cells can only be gripped in certain places using vacuum generators. This means that reliable holding of the cell is not guaranteed.
The handling of sensitive lithium-ion cells is a major challenge for battery manufacturers as the cells can be easily damaged or contaminated during the manufacturing process. If we are to eventually have efficient mass production, we need to set up technologically flexible electrode and cell production for the manufacture of battery prototypes with a high degree of standardisation and automation. Mechatronic solutions which integrate expertise from different areas of process and factory automation and transfer it to the latest technologies in battery production look promising.
Air bearings as a solution
ads-tec, a company which develops automated production systems for high performance lithium energy storage devices first developed a production method for automating the bonding, feeding and handling of cells on a laboratory scale. The aim was to provide production facilities that would allow the fast, low cost production of cells and battery systems.
Engineers worked with Festo to develop a new front-end solution for handling lithium-ion cells, with an air bearing. The ATBT air bearing was initially designed for use in the solar or electrical manufacturing industry. It produces an evenly distributed layer of air on its fine surface, which allows delicate objects to glide smoothly, enabling the reliable contactless transport of sheets of glass and delicate film.
Festo’s experts have now applied the technology to battery production, by making use of a reverse effect. Instead of ‘blowing’ air, the air bearing draws a vacuum which is distributed over the large surface. Their ATBT suction pad has been used in a battery bonding prototype machine, where it is ideal for handling, clamping and holding the delicate cell packs during production
As the new air bearing grips the entire surface of the battery plate, the bonding process is no longer prone to stress fractures caused during production. It is proving to be an effective solution for efficient automation processes and increasing productivity.
Despite their higher costs the level of acceptance for electric cars is growing worldwide. This applies in particular to the emerging markets of China and India, where mobility is also rising. 92% of people in India and 88% in China are willing to consider an electric car if buying a new car within the next five years. In Britain and France this figure is only 57%, but the number is rising and production innovation will help reduce costs and bring forward the emobility revolution!