From old to new – Battery recycling in Salzgitter

The ID.3 and ID.4 models open a new chapter for the Volkswagen brand and the entire Group, by making electromobility suitable for mass production. Electricity is needed to operate the e-vehicles, stored in many small battery cells and modules the size of a shoebox. They are the heart of the e-vehicle – and its key components. But what happens when a battery reaches the end of its life? The solution was discovered by Volkswagen Group Research and Development and made production-ready together with Volkswagen Group Components: an innovative and sustainable process for battery recycling that Volkswagen Group Components is now using in a pilot plant at its Salzgitter site.

“Our goal is to create our own circular process in which more than 90 percent of each of our batteries is recycled,” says Thomas Tiedje, Head of Technical Planning at Volkswagen Component. “We don’t want to hand the process over at any point but prefer to train our employees and thus make them fit for the future.” The distinctive aspect: only batteries that can no longer be used in any other way are sent for recycling. Before that, the modules built into the battery system are checked to see if they are still in good condition and could possibly be given a second life in mobile energy storage systems such as flexible, fast-charging stations or charging robots. This significantly extends the use-phase life of the modules.

From research to development: How Volkswagen ended up recycling

A carmaker that recycles in-house? Around 12 years ago, the idea of Volkswagen doctoral student Stella Konietzko initially caused some bewilderment. The geologist wanted to investigate the sources from which metals such as lithium, cobalt, steel and aluminum could be recovered for the automotive industry – and what role Volkswagen Group itself could play in this. A subject that was actually still a long way off at the time and yet at the same time so relevant that it quickly became a major research project at the Technical University (TU) of Braunschweig. Together with ten other partner companies, the TU and Volkswagen Group developed a process for recycling lithium-ion batteries from 2009 to 2011 to test its feasibility. The winner: the LithoRec process, which is now being put into practice in Salzgitter.

But in 2011, the automotive market still looked very different. The Volkswagen brand cracked the five million mark in deliveries for the first time, the Volkswagen up! was the model of the moment, and MAN was freshly part of the Group. There were barely any recyclable batteries from e-cars around. Nevertheless, development of the LithoRec process was ongoing in Volkswagen’s Technical Development department. “We didn’t start too early, but just in time. Now we have the chance to start with a process that is really economically and ecologically sustainable in the end, without having to rush anything,” explains Marko Gernuks, Head of Life Cycle Optimization at Volkswagen. He has accompanied LithoRec as a project manager for years.

How does battery recycling work?

Until now, used batteries have mostly been recycled in a pyrometallurgical process. In simpler terms, they simply end up in the blast furnace. Volkswagen Group Components first uses a mechanical process: Once the battery enters the recycling process, it is first drained and dismantled. Initial raw materials such as its aluminum casing, copper cable and plastic are already recovered here and returned to the production cycle. Then the battery modules are heavily crushed under a protective atmosphere and the escaping liquid electrolyte turns them into a moist mass, the granulate. This is dried, passed through various sieves and a magnetic belt, and thus becomes finer and finer. Eventually, a so-called “black powder” is produced, which contains, among other things, valuable graphite as well as lithium, manganese, cobalt, and nickel. A partner company from the chemical industry then separates it into its individual components using a hydrometallurgical process, i.e. using water and solvents. These can be used as secondary raw material for the construction of cathodes of new batteries – without any loss of quality compared to new, primary material.

The future’s circular

With this so-called closed-loop approach, Volkswagen Group Components aims to create a closed material cycle that will not only reduce the Group’s primary demand for raw materials in the long term, but can also significantly reduce the CO₂ footprint of the batteries. “If we produce our cathodes exclusively from recycled material, we will save more than one ton of CO₂ per vehicle,” says Thomas Tiedje. The first step into industrialized battery recycling therefore contributes directly to climate protection. In the long term, the professional disposal of the battery and the reprocessing of its valuable components has an ecologically and economically sustainable effect. If the costs fall, the customer benefits. This is another goal of the circular economy of future mobility. The next steps at Volkswagen Group Components in Salzgitter are therefore: optimize, optimize, optimize. As soon as the pilot plant has reached its capacity limit, larger plants can follow – so that e-mobility becomes suitable for mass production despite limited raw materials.