The HVBatCycle research consortium, led by Volkswagen, has been established with the goal of keeping cathode metals, electrolyte and graphite permanently in a closed material cycle (closed loop). The Volkswagen Group, Taniobis GmbH, J. Schmalz GmbH and Viscom AG are working together with researchers from RWTH Aachen University, TU Braunschweig and the Fraunhofer Institute for surface engineering and thin films (IST) for three years to research and develop the necessary processes. The project is funded by the German Federal Ministry for Economic Affairs and Climate Action.
Michael Kellner, a parliamentary state secretary in Germany, says, “European battery production can only be successful if it focuses on sustainability in as many areas as possible. Sustainable batteries are crucial for an energy and transport transition that is guided by high environmental and social standards.”
Sebastian Wolf, chief operating officer battery cell at Volkswagen AG, says, “The recycling of batteries and production rejects makes a decisive contribution to securing the supply of raw materials for our planned factories. Though the HVBatCycle project, a holistic view of the recycling processes and thereby the implementation of the closed loop of battery materials is being prepared.”
In order to have to use fewer materials from primary sources such as mines or salt flats, Volkswagen says essential raw materials can be recovered not just once, but several times. Battery cells made from recycled material are recycled again, proving that multiple recycling runs have no influence on the material quality. Closing the loop requires complex interdisciplinary processes, the company says. For efficient and ecologically and economically sensible recycling, all processes must be coordinated with requirements.
The consortium project focuses on the mechanical-hydrometallurgical recycling route, which Volkswagen says is characterized by low energy requirements and the possibility of a comparatively simple decentralized distribution of certain recycling processes in Europe. This favors a local circular economy and secures strategically important raw materials, which significantly reduces Europe’s dependence on other regions of the world. The HVBatCycle project aims to identify efficient processes and innovative solutions that ensure the establishment of an end-to-end value chain with high economic efficiency while also maximizing recycling and energy efficiency and minimizing environmental impact.
Concrete innovative development approaches lie in a demand-oriented discharge and a largely automated dismantling of declining battery systems down to cell or electrode level, the company says. This also includes an almost loss-free separation of an active material and carrier foils as well as the recovery of graphite and highly volatile electrolyte components.
In the hydrometallurgical processing of the “black mass,” which consists of graphite and battery metals, using water and chemical solvents, the focus is on early and selective extraction of the lithium in soluble form as well as leaching, precipitation and refining of contained metals as a mixed hydroxide concentrate, Volkswagen says. In connection with the renewed material synthesis of cathodic active material, the consortium will investigate whether the separation of metal compounds is necessary to produce new, fully high-performance cathode material.
Through research on the processing of the electrolyte and the graphite, the consortium intends to show that important electrolyte components and the graphite can also be efficiently processed and used again in battery-suitable quality in cell production. All process steps are holistically accompanied by an ecological and economic life cycle analysis, according to the company.
In February 2021, Volkswagen opened its first plant for recycling electric car batteries in Salzgitter, Germany, as reported in a previous Recycling Today article. The plant has established the basis for the construction of a battery cell factory set to go into operation in 2025.
According to the Volkswagen website, “The Salzgitter gigafactory will manufacture unified cells for the volume segment of the Volkswagen Group. In the first stage, the factory will produce an annual capacity of 20 gigawatt-hours. It is planned to prospectively double this to a capacity of 40 gigawatt-hours.”Another previous Recycling Today article covered the announcement of a joint venture between Umicore and Volkswagen to develop precursor and cathode material for electric vehicle battery cell production in Europe.