Battery: lithium and cobalt
The light metal lithium reacts very quickly with other chemical elements in its environment. Consequently, it occurs in nature only in the form of compounds such as lithium carbonate or lithium chloride. These compounds are generally found in volcanic rock or (usually dried-up) salt lakes. According to the German Mineral Resources Agency (DERA), Australia currently mines the most lithium – nearly 13,200 metric tons in 2015 – followed by Chile with 11,800 metric tons and Argentina with 3,500 metric tons. According to DERA, the world’s largest minable lithium reserves (using today’s methods) can be found in the salt lakes of South America: around 9 million metric tons in Bolivia alone and 7.5 million metric tons in Chile.
Extraction of lithium
To obtain pure lithium, lithium-based compounds need to be put through a complex chemical process. Pumping off brine, which is then left to evaporate, is the easiest process step. One of the many subsequent stages is again the molten-salt electrolysis, with which it is possible to extract not only pure aluminum, but also pure lithium. Pure lithium is, however, very unstable: it reacts with its surroundings at even low humidity levels.
Production of a battery cell
A lithium-ion battery consists of many small batteries, known as cells. These, in turn, are constructed out of copper and aluminum – but the positive pole, the cathode, is what is crucial. It consists of a layer of lithium metal oxide. When the battery is charged up, lithium ions migrate from the cathode to the negative terminal, the anode, which consists of graphite. While the car is out on the road – in other words, consuming energy – the ions migrate back to the positive terminal. Researchers are continuously developing the batteries, experimenting with different materials and construction methods, and thus gradually increasing the range and lifespan of batteries. Today, an e-Golf can drive up to 300 kilometers on a single battery charge.
Challenge and approach
Smartphones, laptops, and electric cars: they all currently run on lithium-ion batteries. And the demand for lithium is expected to rise sharply, according to the German Mineral Resources Agency (DERA): the demand for lithium-ion batteries for electric cars alone could rise by up to 33 percent every year up until 2025. Experts believe that the world reserves should last for about 150 years if the technology does not develop significantly and demand stops increasing after 2025.
More mining, different charging methods, more recycling
Three possibilities could resolve the dilemma:
1) New deposits: More companies develop new deposits, for example in Bolivia. The Volkswagen Group maintains a constant exchange with its partners on the subject of securing raw materials.
2) New technologies: Making the batteries more efficient. Researchers at the Volkswagen Group expect that by the year 2020 the energy density of lithium-ion batteries will have doubled compared with today. And, last but not least, scientists are continuously exploring new materials which are similarly conductive, can store energy even better, and also be recharged.
3) Recycling lithium batteries: Since 2009, the Volkswagen Group has been exploring how it can recover and reuse ever more materials from battery recycling. Today, materials such as nickel and cobalt are already being recovered from Volkswagen batteries.
Cobalt, a brittle, unimposing heavy metal, brings electric vehicles to life.
The brittle heavy metal cobalt is produced almost exclusively as a by-product of industrial nickel and copper production. Cobalt is the main mined product in only about 2 percent of the worldwide extraction – this is mostly in Madagascar or the small-scale mining sector in the Democratic Republic of the Congo. With a share of around 60 percent of global production, Congo is the world’s most important mining region for cobalt. It is followed by China, Canada, and Australia.
Production of cathode material
One important raw material for the manufacture of battery cells is the so-called cathode material. To produce cathode material, cobalt sulfate is chemically combined with nickel sulfate and manganese sulfate. The quality standards are very high here: the purer the cathode material, the better the battery performs and the longer its lifespan. The finished mixture is then combined with lithium carbonate at high temperatures and sold on to the manufacturers of battery cells.
The marriage of battery modules
The battery cell is the smallest unit of a battery. Once put together, the cells form a module. At a factory in Brunswick, Volkswagen connects up each delivered battery module and assembles them into vehicle batteries for electric vehicles. The battery of an e-Golf, for example, consists of 264 cells that are connected in 27 modules to create a single component. The finished battery is also equipped with a so-called management system that controls and monitors each cell.
Challenge and approach
Precarious working conditions in small mines
More than 100,000 people in the Eastern Congolese provinces Haut-Katanga and Lualaba live from small-scale cobalt mining. The miners dig up cobalt ores for about $35 a month. A 2016 study by Amnesty International indicates that, in small-scale mining, often neither labor nor health and safety standards are applied. This means that workers, in some cases including children, face an increased risk of accidents in the unsecured mines.
Transparency, cooperation, and commitment
Volkswagen communicates with its battery suppliers about their sources of supply to enforce the Group’s sustainability requirements. The path from the extraction of raw materials to the finished battery in the vehicle is, however, complex and branched worldwide. This is why Volkswagen has been working within the framework of the Responsible Raw Materials Initiative (RRMI) to establish a certification system for cobalt smelting, to be able to prove the origin of the material for its batteries and thus to improve mining conditions. In addition, the Group is also a member of Global Battery Alliance of the World Economic Forum. The alliance of public and private sector partners wants to ensure social and environmental sustainability in the battery raw materials value chain – and not only for cobalt.