Author: Marianna Hietaniemi
Title: Comparison of single crystal and polycrystalline lithiation for NCM622 cathode materials
Affiliation: University of Oulu
Single crystal cathode active materials are commercially available, and several reports indicate them having better cycle life and better high voltage cyclability. Very few publications, however, compare single crystal material with traditional polycrystalline materials prepared from the same NCM precursor.
First, electrochemical performance under different conditions is compared to see the difference between normal lithiation and single crystal lithiation. Coin cells are assembled and tested at room temperature, at elevated temperature and with high voltage cycling. They were also tested before and after washing and milling treatment. Secondly, the effect of lithiation on different precursors and their suitability for single crystal lithiation was investigated. Several NCM622 precursors were precipitated and their performance after different lithiation conditions was compared. Materials varied in particle size, particle size distribution, tap density and purity.