The electric vehicle revolution, driven by the need to decarbonise private transport and improve air quality in urban centres, will not only radically change the automotive industry. The associated battery industry and ultimately the waste and recycling industry are also facing fundamental changes. In this context, one category of batteries is playing an increasingly central role due to their energy storage capacity and low weight: lithium-ion batteries (LIBs, also known as lithium-ion accumulators). Basically, the individual small battery cells of a LIB consist of conductive aluminium or copper layers. Between them are an anode, usually made of graphite, and a cathode, the composition of which varies greatly depending on the technology: While currently many lithium iron phosphate batteries and lithium nickel cobalt aluminium batteries are still used, in the future mainly the lithium nickel manganese cobalt technology will be used in different compositions. Consequently, lithium, cobalt, nickel, manganese and graphite in particular will play an increasingly decisive role in the global raw materials market as important battery raw materials. So far, most LIBs have been sold in the consumer electronics sector, but future sales will increasingly be driven by electric vehicles.
Already in 2017, an estimated one million LIBs accounted for about six per cent of total demand for cobalt and nine per cent of total demand for lithium. This trend is particularly visible in China, where more than 73 per cent of global lithium cell production capacity was already in place in 2019, according to Bloomberg New Energy Finance, followed by the US, which is second with 12 per cent of global capacity. Global demand for batteries will increase 14-fold by 2030 and the EU could meet 17 per cent of this demand. In addition, the exponential global growth in demand for batteries will lead to a corresponding increase in demand for raw materials, especially cobalt, lithium, nickel and manganese, which will have a significant impact on the environment.
The increasing use of batteries will also lead to an increase in waste volumes. The number of recyclable lithium batteries is expected to increase 700-fold between 2020 and 2040. Establishing a suitable economic system for the disposal of WEEE (Waste Electrical & Electronic Equipment) and LIB waste therefore seems essential.
Great benefits and great challenges: Recycling LIBs
In general, when recycling batteries, a distinction must be made between pure reuse and the extraction of raw materials. After primary use in electric vehicles, for example, used batteries are expected to retain 60 to 80 per cent of their original capacity, which makes reuse in other applications such as grid storage possible. However, if the batteries no longer have any use, they must be disposed of and, at best, recycled. Recycling LIBs is a comparatively complex and sometimes very energy-intensive process. According to a study by McKinsey&Company, the industry is currently mainly concerned with the disposal of potentially hazardous used consumer electronics products instead of extracting the materials for reuse. With today's recycling processes, only cobalt, nickel and, to some extent, manganese can be economically recovered from active materials. McKinsey&Company estimate that 12 to 15 kilotonnes of cobalt and almost no lithium were recovered from recycling in 2017. Lithium has so far only been extracted in experimental pilot plants and mostly remains in the slag in previous plants.
An important factor in the economic viability of recycling lithium, nickel, cobalt and possibly manganese is that the materials continue to be used in cell chemistries in relatively high proportions. If the composition and proportion of the materials changes in the future, recycling could also become uneconomical here. In existing pilot plants, LIBs are first laboriously unloaded manually, dismantled, and then processed either pyrometallurgically (melting and extraction) or hydrometallurgically (leaching and extraction). In the thermal treatment, lithium can, for example, be washed from the subsequent slag or recovered from flue gas plants. In the hydrometallurgical process, on the other hand, materials are treated with acids and alkalis to separate them from each other. Due to the energy-intensive nature of pyrometallurgical processes, it is more likely that the hydrometallurgical process will be developed further in the future. However, despite the fact that the recycling process is still costly, European countries are likely to have a strong interest in its rapid development: Some studies indicate that electric vehicles emit more greenhouse gases during production and less during the use phase compared to vehicles with combustion engines. Therefore, reducing emissions during production will be one of the main concerns in order to reap the emission benefits of electric mobility. In this context, the use of recycled materials is seen as a crucial method. In fact, according to a study by Tsinghua University, recycling electric vehicles can help reduce about 35 per cent of energy consumption and greenhouse gas emissions during the manufacturing phase. Moreover, in the case of LIBs, incorrect storage and disposal can mean not only a loss of important raw materials, but also environmental pollution and health risks.
But it is not only the environmental and health risks that are becoming increasingly relevant. The strong global demand for necessary raw materials can also lead to supply bottlenecks. Disruptions in the supply chain of raw materials can drive up material costs and thus reduce the benefit of learning effects in lowering battery prices. This was already the case in late 2018, when the price of cobalt more than quadrupled in 15 months, partly due to rising demand and partly due to political instability in the largest cobalt producer - the Democratic Republic of Congo. Although the price of cobalt has fallen since then, concerns about supply shortages and commodity price volatility persist. Thus, recycling represents an opportunity to reduce both supply risks and negative externalities in production as well as subsequent extraction of critical elements.
▪ FAZ: So werden Lithium-Ionen-Akkus recycelt. (German)