As part of the EU-funded ECO COM’BAT, ten partners from industry and research have been working on more sustainable high-voltage lithium-ion batteries since April 2016. As the project coordinator Fraunhofer ISC now communicates: apparently with success.
The aim of the project was to combine environmentally friendly and high-performance materials for the next generation of high-voltage lithium-ion batteries and to improve their production. The focus was on several materials, including fluorine in addition to the well-known cobalt. “The main task of the ECO COM’BAT project was to replace conventional, often expensive, rare or even critical materials such as cobalt in the electrodes and fluorine in the electrolyte,” says project coordinator Andreas Bittner of the Fraunhofer ISC.
A battery cell was developed, which makes do with 20 per cent less cobalt and over 60 per cent less fluorine. According to the Fraunhofer ISC, the new development in the form of a common pouch cell is said to have shown up to 50 per cent higher cycle stability (at 4.3 V) than the industrial reference samples in the comparative test.
For this purpose, the NMC-622 cathode was specially coated and a new high-voltage electrolyte was used. These were then adapted and optimized to the requirements of the battery cell. Since the participating research institutes also cooperated with the material manufacturers Arkema and Umicore and the cell manufacturers Saft and Custom Cells, attention was paid from the outset to possible production. The researchers have already been able to produce batch sizes of up to 20 kilograms – it usually takes much longer from the development of a new cell technology in the laboratory to large-scale production.
In addition, an efficient recycling concept was developed and tested in order to recover valuable materials such as nickel, cobalt, graphite and lithium not only in elementary form, but also in the form of processed functional materials. The aim is to achieve a high degree of sustainability. Umicore, a well-known battery recycler, was already involved in the project.