Characterization of Li-Ion Cathode Materials Directly Recycled via Induction Heating from Production Scraps

The direct recycling of electrode scraps represents an attractive opportunity to reduce costs and CO 2 emissions in battery cell production and to make the product life cycle more sustainable. Induction heating as a recycling method offers high energy efficiency, flexible process control and short heating times. Based on previous work in which we recovered cathode materials by induction heating, we analyze the recycled materials and reuse them in new battery cells. The recycled materials show no fundamental change in crystal structure but exhibit progressive LiF formation on the cathode active material surface with increasing recycling temperatures. The LiF deteriorates the electrochemical performance of the recycled cathodes by both, inactively binding parts of the Li inventory and increasing the charge transfer resistance. However, a recycling temperature of 300 °C which already has been proven in our previous work to be favourable in terms of decoating efficiency is still enabling good electrochemical performance. Other challenges for the direct recycling of electrode scraps identified in this work are agglomeration and generally uneven distribution of binder and carbon black in the electrodes produced from recycled cathode powders. This can increase the ionic and the electrical resistance and reduce the adhesion strength of the electrodes.