There is hardly a transport discussion that doesn’t mention electric vehicles – and the batteries. What about the disposal of these batteries and some of the hazardous substances they contain?? This is what a BR24 reader asked. The #faktenfuchs answers.
The environmental weak point of battery-powered e-vehicles – at least at the current stage of development – is their core component: the battery. In the accumulators are contained among other things lithium and cobalt. Its mining damages the environment in the raw material countries, for example in chile or the congo. The production of batteries produces fine dust, and if the electricity still has a high fossil content, for example coal, the CO2 load is also depressed.
And how does it look when the battery has done its service? "What disposal problems can arise from batteries that also contain toxic substances??" a BR24 user asked us. The fact fox compiles the most important information.
Toxic liquid in the lithium-ion battery
Batteries for electric vehicles – whether cars, scooters, bicycles or scooters – are almost all based on lithium-ion technology. Unlike many other batteries, such batteries do not generally contain toxic heavy metals such as mercury, cadmium or lead.
But the so-called electrolyte inside the lithium-ion cells poses problems. For this viscous liquid in which the electrons move contains toxic, highly corrosive fluorine, is highly reactive and flammable. If the battery is cracked, for example, a short circuit may occur and the battery may catch fire.
Recycling centers are already struggling with batteries that – as they should not – end up in waste and catch fire. "Consumers often do not separate rechargeable batteries from the rest of the waste as required by law, says andreas biermann, disposal expert at DEKRA certification. "In many recycling centers, scrap is also not carefully inspected upon delivery."
Used batteries: 50 percent of them must be recycled
The old batteries must not only be returned to the distributors or the collection points. An EU directive requires all member states to ensure that at least 50 percent of the materials in lithium-containing batteries are recycled at the end of the recycling process. This means that if a used battery goes to a recycling plant, at least half of it must actually be recycled. The rest could leave the plant unrecycled, so to speak. According to falk petrikowski of the federal environment Agency, this requirement for the 50 percent is often already achieved to a large extent by the manual or automated dismantling of the casing, the wiring and components for cooling the cells.
Six specialized recyclers in germany
The flammable and volatile electrolyte fluid is also one of the key issues in recycling. This must be separated from the other materials of the cells. Only a few companies have mastered such procedures, as well as the recycling of lithium-ion batteries in general.
"As of the end of 2018, there are six recycling plants for used lithium batteries in germany, says falk petrikowski. "The recycling processes must constantly be adapted to the new cell chemistries in such a way that the existing high safety and environmental standards are consistently met. The recyclers’ own interest in implementing demanding standards is high", according to petrikowski. The occasional fires at waste battery sorting plants or recycling centers. -recyclers would have shown how extensive and severe the impact can be.
Voltage of several hundred volts
In recycling, even opening the battery is challenging. Example of a lithium-ion battery in an electric car: such a battery is made up of many individual elements, similar to a modular system – battery cells make up modules. Several modules are then joined together in a single housing.
image rights: dpa
The battery block of an electric car contains many battery modules strung together. Here’s a renault exhibit, paris auto show 2016.
"Depending on the type, the batteries have voltages of several hundred volts and can often not be easily discharged from the outside before dismantling. The batteries are also welded or glued, which makes them even more difficult to open", felk petrikowski explains. And because there are so many different sizes and shapes, there are no robots to do the job. Workers dismantle the batteries by hand.
Recycling of the battery case
After the battery has been opened, the casing and wiring are first removed. They contain aluminum and copper. This step offers the greatest and easiest profit for recycling. The Karlsruhe Institute of Technology (KIT) evaluated several studies and wrote in 2018 in the final report of an expert forum: "The majority of the studies conclude that the greatest benefit is achieved in the first process steps, i.e. the mechanical disassembly of the battery packs, their housings and battery modules, where the individual components can be completely separated by type and individually fed into a suitable recycling process."
Recycling of raw materials is not always worthwhile
The individual battery cells contain many different substances in only very small quantities and are difficult to separate out. This means several work processes. "Cobalt is the material that makes money", the expert from the federal environment agency states. A yield of nickel is also worthwhile – ecologically and financially. The mining of both materials is associated with high environmental pollution in the countries of origin, and the raw materials are relatively expensive. The cobalt content in the batteries has decreased in the last few years.
For other materials, recycling may not be worthwhile. "Case by case", according to the karlsruher institute’s workshop report, it can even be more environmentally harmful to recycle lithium or iron than to mine new material. Both metals are easy to extract. Although the eco-institute in freiburg also calls for the recovery of lithium. But extracting this material from old batteries is very complex, requires a large number of steps, and usually involves the use of large quantities of chemicals.
After the complete recycling process, a kind of slag remains from the batteries. According to petrikowski, this can still be used, for example, for the construction of public roads or for roads in landfills.
There is a lot of research into batteries and recycling processes. Among other things, recycling of as many valuable materials as possible should become economical. The Fraunhofer IWKS is relying on mechanical processes that eliminate the need for previous chemical or thermal steps. The reduction of hazards is also being addressed in research projects.
Second life for batteries
The German federal government has also been funding various electromobility research projects for the past ten years. Including the possibilities for battery reuse. When the drive batteries in vehicles have reached a performance level of 70 to 80 percent, they are usually discarded, but can still be used for other purposes. Audi in Ingolstadt, for example, is testing the possibility of reusing used batteries from e-mobiles for forklifts and tractors in its factories. Another possibility is to give the batteries a "second life" in solar systems for the batteries.
In the case of batteries for electromobility, lithium-ion technology is being further developed. Research is also being conducted into other types of batteries, such as solid-state cells.
Recycling lithium-ion batteries from e-vehicles faces several hurdles: the high voltage of several hundred volts in the batteries, the flammable and fluorine-containing liquid that must be separated out in the work process. In addition, lithium-ion batteries contain many different substances in very small quantities, which makes many work steps necessary. Recycling companies have to deal with a lot of different types of factories. This also complicates the work.
There may be cases where the recovery of metals, for example, is not economically or ecologically viable. This is pointed out by the karlsruhe institute of technology in a 2018 report. One of these materials is lithium. Cobalt or nickel are more lucrative. In Germany, there are now six recycling companies that specialize in batteries of the kind used in e-mobiles. According to the German Federal Environment Agency, it is also in the interest of recycling companies to comply with standards – if only for the sake of safety in their own operations.