Research spotlight – the battery
The battery is the heart of the electric car. Batteries are today quite safe, and last for a vehicle’s lifetime. Yet there is still room for improvement. Volkswagen is driving this development forward with intensive research.
Shielded and hidden behind a heavy door in the middle of the VW headquarters in Wolfsburg Germany, lies the inner sanctum of electric drive technology: the battery lab. Grey cabinets connected by thick power cords line the wall of the research and development think tank.
Inside the cabinets are the so-called cells. Dozens of these in combination, furnished with complex electronics, form the battery. The cells are constantly charging and discharging, for several months at a time, in simulated heat and artificially produced cold. Test after test.
Worldwide, Volkswagen AG invests about eight billion euros in research and development every year. A significant portion of this flows into electric car and battery technology. Next to the electric motor itself, the battery is the most vital component of the electric vehicle, and considerable potential for development remains.
Li metal compound on a conductor film
Porous plastic film or laminate
The combination of materials, for example, is a science in itself. In producing the widely used lithium-ion batteries, about 300 different combinations of materials are possible, with a variety of effects on storage properties. The research mandate is clear: Find the best mixture!
Perhaps the most important property is vehicle range. Many people are reluctant to buy an electric car, fearful that one battery charge won’t take them far enough. But today, electric cars such as the e-up! can travel about 160 kilometres, enough for 97 percent of all daily trips. Further leaps in efficiency are certain in the years to come.
That’s why Volkswagen operates research satellites such as the Electronics Research Laboratory, and works closely with universities, research institutes and high-tech companies. In Wolfsburg, battery researchers will soon get a new laboratory tailored wholly to the needs of electric mobility. The electro-campus is currently under development at the group headquarters. More than 1,000 employees will work to advance battery technology there, among other tasks.
The energy content of a lithium-ion battery is lower than that of conventional fuels. However, their energy storage capacity can be developed. Today’s energy density of about 140 watt hours per kilogram is likely to reach 200 watt hours in the coming years, or even 250 over the long term. The next generation of batteries is already in the basic research stage. With a metal-air battery, ranges of up to 600 kilometres might someday be possible.
The high energy density in a confined space can lead to short circuits and fires. Volkswagen continues to research materials that will avoid triggering unwanted chemical reactions. The battery is already positioned within the vehicle so that it can’t be damaged in an accident. In all cars, the new MQB platform (Modular Transverse Matrix) guarantees a safe place for the batter packs along with the Battery Management System and the high-voltage cables.
CostWithout the battery, producing an electric car would be about as expensive as a diesel or petrol-powered vehicle. The costs for electric components such as the electric motor or power electronics approximate the prices of the traditional parts they replace. The price premium comes entirely from the battery, which alone adds several thousand dollars to the cost.
Lithium is the oil of the 21st century
The metal is the most important element in a modern battery, making it a sought-after raw material.
It looks a little like powdered sugar. But this white, unassuming powder is really something else. Lithium is the most important component of the lithium-ion battery, which can be found in hundreds of millions electric vehicles, mobile telephones, and tablet and notebook computers. Swedish chemist Johan August Arfwedson discovered lithium in 1817, and it has since become a key raw material.
The abbreviation of lithium in the Periodic Table is Li. It has the lowest density of all the solid elements and is highly reactive. Total global reserves are estimated at six million tonnes. But 17,000 tonnes were mined in 2008 alone, and production is increasing. Lithium is also distributed unevenly on the planet.
Chile is currently the most important producer of lithium, followed by Argentina, the United States, and then China. There are no lithium deposits in Europe. Given its importance for the production of batteries in electric vehicles, some wonder whether the success of e-vehicles could be hampered should lithium supplies ever diminish.
But the concern is actually unfounded. For one thing, most of the lithium in expired batteries is recycled. And according to a study by Germany’s Frauenhofer Gesellschaft, even if e-cars were suddenly to flood the market, there are enough lithium reserves to last until 2050. So lithium is not likely to end up on the list of threatened materials.