Effect of impurities caused by a recycling process on the electrochemical performance of Li[Ni0.33Co0.33Mn0.33]O2

Abstract

Electrodes containing the cathode material Li[Ni0.33Co0.33Mn0.33]O2 (NCM) were recycled in order to test a newly developed recycling concept which is aiming towards commercial application. For this purpose, cathodes from electrode production rejects and from spent lithium-ion battery cells were removed from the current collector using a cutting mill. The active material was dissolved in sulphuric acid and separated from the binder and the carbonaceous conductive additive. The gained solutions, containing the dissolved active cathode material, were analyzed using ICP-OES and synthetically remerged matching to these solutions. New cathode material was synthesized from remerged solutions in a bigger scale using an industrial process. The recycled materials and thus the prepared solutions exhibited different aluminum impurities (stemming from the current collector) which had an impact on the forming of secondary particles during re-synthesis. The electrochemical performance of the recycled materials was influenced by the detected impurities.