Washing of nickel-rich cathode materials for lithiumion batteries: Towards a mechanistic understanding

Daniel Pritzl, Tobias Teufl, Anna T.S. Freiberg, Benjamin Strehle, Johannes Sicklinger, Heino Sommer, Pascal Hartmann, Hubert A. Gasteiger

Research output: Contribution to journalArticlepeer-review

149 Scopus citations

Abstract

Washing is a commonly used method to remove surface impurities of cathode materials for lithium-ion batteries. However, a clear mechanistic understanding of the washing process is missing in the literature. In this study, we will investigate the effect of washing and subsequent drying of nickel-rich NCM cathodes (85% nickel) with respect to gassing and impedance of the washed cathodes. By on-line electrochemical mass spectrometry (OEMS), we will show a drastic reduction of the O2 release above 80% SOC for the NCM washed with deionized water, suggesting the formation of an oxygen-depleted surface layer on the NCM particle surface. The modification of the surface can be confirmed by a strong impedance buildup of cathodes composed of washed NCM (using a microreference electrode in a full-cell), revealing that the impedance increases strongly with increasing drying temperature after washing. Last, we will propose a comprehensive mechanism on the processes occurring during the washing/drying process of nickel-rich NCM materials and identify the drying temperature after washing as the dominant factor influencing the surface properties.

Original languageEnglish
Pages (from-to)A4056-A4066
JournalJournal of the Electrochemical Society
Volume166
Issue number16
DOIs
StatePublished - 2019

Fingerprint

Dive into the research topics of 'Washing of nickel-rich cathode materials for lithiumion batteries: Towards a mechanistic understanding'. Together they form a unique fingerprint.

Cite this