Duesenfeld system focuses on battery cell scrap

A system for recycling lithium-ion batteries has been established by Duesenfeld. This system supplies graphite and electrolytes that are marketable, and it also produces marketable metals.

Duesenfeld’s patented process begins with discharging end-of-life lithium-ion batteries, along with the recovery of the embedded energy. Then it uses thermodynamic, mechanical, and hydrometallurgical processes. The company has stated that ‘the process achieves the highest material recovery rates with low energy consumption while avoiding pollutants.’

Whilst the company’s definition of recycling does not extend to paving materials, they have stated that ‘all metals are recovered with high recovery rates in the form of high-quality secondary raw materials up to battery quality. Shredded dry electrode scrap generated by battery cell production can be taken to a sorting stage where the material is separated into different fractions based on physical properties such as grain size, density, and magnetic and electrical properties, and then they are further processed metallurgically.’

Once this process is complete, the aluminium, iron, and copper, which are produced as a result, go on to be sold to established markets. Whereas materials, including Duesenfeld Black (black mass), go to Duesenfeld’s hydrometallurgical process. This is because this material contains conductive salt and electrode active materials. Throughout this part of the process, materials that are recovered include nickel, manganese, cobalt, lithium, and graphite.

The research and technology licensing company says, “Our focus is on recycling the batteries as completely as possible,” plus, ‘it has achieved a recycling rate of 72 percent of lithium-ion battery materials in its mechanical recycling stage.’

Duesenfeld also mentioned that the company’s ‘hydrometallurgical step increases the material recycling rate to 91.’

“Only the separator film and the high boiler portion of the electrolyte are not recovered at the moment,” the company stated.

Duesenfeld said, ‘Those outcomes are made possible by a process with low temperatures in which toxic hydrogen fluorides are not produced.’

“[After disassembly,] the batteries are comminuted under an inert gas atmosphere and the solvent of the electrolyte is recovered from the comminuted material by vacuum distillation,” Duesenfeld says.

The company reported that, ‘In a pilot project, a recycling rate of more than 90  was achieved for an industrial nickel manganese cobalt (NMC) cathode scrap stream, with what it calls an extremely low fraction of aluminium impurities.’

The firm also stated that, ‘laboratory testing has shown that cells with 26 percent recycled content were certified as having a performance comparable to that of reference (primary materials) cells.’