The battery recycling market is coming up with numerous new developments. These include the application areas of vacuum technology, such as processes that vary in the different source materials and battery formats, or process adaptations to reduce the environmental impact. Battery-News spoke to market coordinator Bastian Schöchert, who is responsible for battery recycling at Busch Vacuum Solutions – part of the Busch Group – about the requirements, challenges, and trends in this area of the battery market.
Battery-News: Where is vacuum technology actually used in the recycling of lithium-ion batteries?
Bastian Schöchert: To enable the shift from conventional to electric mobility, the availability of resources must be secured. Like for any other product, recycling is a cost-efficient and sustainable way to reduce the need for a constant flow of freshly mined resources. New, promising recycling methods that use processes under vacuum can reach a recycling rate of up to 91 percent. There are several main techniques used to recycle lithium-ion batteries, in each of which vacuum plays a vital role: mechanical treatment, hydrometallurgy, and pyrometallurgy. Each method alone has low recovery rates, and some are very energy-intensive. New approaches use vacuum technology and a combination of these methods to achieve higher recycling rates and therefore increase the total recovery rate. For example, under vacuum, the electrolyte can be almost completely recovered, and carbon emissions can be significantly reduced by conducting the process at lower temperatures.
“Without recycling, the boom in electric mobility will rapidly deplete our currently known lithium reserves.”
Bastian Schöchert, Market Coordinator at Busch Vacuum Solutions
Battery-News: What are the current drivers in the market?
Schöchert: It is well known that the battery pack is the most expensive part of an electric vehicle. It can account for up to 50 percent of its total cost, with the majority stemming from the materials. It therefore makes economic sense to recycle as much as possible and avoid having to purchase new materials for each new battery. Also, there are environmental considerations throughout the batteryʼs life cycle. The valuable metals contained in a lithium-ion battery, such as lithium, nickel, and cobalt, are finite materials – and demand is growing. Without recycling, the boom in electric mobility will rapidly deplete our currently known lithium reserves. This was recognized by the EU in its 2023 directive, which defines clear recycling goals for the different materials in a battery. It is all the more important that the shift from conventional to electric mobility is also carried out sustainably, and the availability of these resources must be secured in a way that has as little impact on the planet as possible. Furthermore, once a lithium-ion battery reaches the end of its life, it must be disposed of correctly. The materials inside can be hazardous to the environment if released.
Battery-News: What are the biggest challenges currently facing vacuum technology in battery recycling?
Schöchert: The variety of different raw materials inside a battery make recycling a complex process that, if done incorrectly, can cause dangerous conditions. When selecting a vacuum pump for battery recycling, its ability to handle reactive chemicals has to be considered; for example, corrosion resistance must be assured. During the process, acids such as hydrogen fluoride can form through reactions of the binder materials or the solvents. In addition, the inorganic electrolytes may be toxic and can react violently with water. The organic solvents used as electrolytes, such as ethylene carbonate or propylene carbonate, can also ignite under certain conditions. Furthermore, to reach a low carbon footprint per battery, maintaining low power consumption while delivering the required vacuum pressure is advantageous. Due to the varying pressure required for different processes, the vacuum pumpʼs performance under different vacuum conditions should also be taken into consideration. Certain electrolyte components have low vapor pressures, and, depending on the temperature level, high vacuum will be required to recover these components.
“Vacuum plays an important role in all chemical processes, from the transport of raw materials to the distillation of the end products.”
Bastian Schöchert, Market Coordinator at Busch Vacuum Solutions
Battery-News: Are there any other important requirements for your vacuum solutions when recycling lithium-ion batteries?
Schöchert: Vacuum plays an important role in all chemical processes, from the transport of raw materials to the distillation of the end products. Worldwide, many companies in the field of chemical and pharmaceutical process engineering trust vacuum technology solutions from Busch Group. Thanks to our many years of experience in the chemical industry, we can rely on an extensive product portfolio of ATEX-certified vacuum pumps, and our customers can also depend on our ATEX expertise as well as process knowledge in the engineering phase, such as in risk analyses and HAZOP studies. We also support the system operators requiring monitoring by carrying out regular tests as part of our ATEX check. If requested, we will carry out electrical and mechanical testing of relevant components, as well as calibration, functional testing, and checking the defined switch-off points of the installed sensors. Also, inspecting electric motors is usually part of our services.
Battery-News: What unique selling point do you use to promote your technology?
Schöchert: We are a one-stop shop, meaning that all vacuum and leak detection equipment needs can be purchased from a single source. An important aspect in the battery industry is a quick response time in the event of an error. This is where Busch Group can score with its global service network. Apart from that, our leak testing services include feasibility and cycle time studies, contract leak testing, and residual gas analysis, which can be carried out in our global application laboratories.
Editorʼs note: More information on such services is available in a previous Battery News interview:
Searching for Leaks: “Battery Production Creates Growing Demand for Vacuum Technology”
Battery-News: The battery recycling market is growing alongside the cell production market. Where and with what solutions has the Busch Group positioned itself in cell production?
Schöchert: In order to ensure that lithium-ion batteries function properly, their integrity and impermeability to external influences is crucial. For example, penetrating moisture can affect quality and safety. For this reason, leak detection systems are used in battery production to test the batteries. When mixing the slurry, vacuum technology ensures that air pockets are avoided. Drying the coated electrodes under vacuum keeps residual moisture to a minimum. When filling the cell, the electrolyte is introduced under vacuum using a high-precision dosing lance. As part of the formation of battery cells, strong gas development occurs during the first charging process. The escaping gases are extracted under a protective atmosphere to create vacuum. To ensure the long-term performance and safe operation of a battery, not only is vacuum required in the upstream production steps, but leak detection is also an essential step in quality control. Leak tests are carried out at various times during value creation. All in all, vacuum and leak detection technologies are essential in the manufacturing process of lithium-ion batteries, from mixing to recycling: Vacuum Solutions for the Lithium-Ion Battery Manufacturing Process | Busch Global
“Vacuum technology will play a similar role in the solid-state battery processes being discussed today as it does in current lithium-ion batteries.”
Bastian Schöchert, Market Coordinator at Busch Vacuum Solutions
Battery-News: Finally, letʼs take a look into the future – and thus into the time after todayʼs lithium-ion battery. What potential do you see in the solid-state battery and the corresponding vaccum technology?
Schöchert: Some manufacturing processes currently requiring the use of vacuum technology will probably no longer be used, such as filling, soaking, and formation. Instead, vacuum generation will become more important in other process steps, such as in electrode coating and in the subsequent drying stage. This will depend on the cell chemistry and the cell format. The recycling processes for solid-state batteries are not yet fully developed, but I believe vacuum technology will play a similar role to that for todayʼs lithium-ion batteries.
