Monitoring the Formation of Nickel-Poor and Nickel-Rich Oxide Cathode Materials for Lithium-Ion Batteries with Synchrotron Radiation
Bixian Ying, Jack R. Fitzpatrick, Zhenjie Teng, Tianxiang Chen, Tsz Woon Benedict Lo, Vassilios Siozios, Claire A. Murray, Helen E. A. Brand, Sarah J. Day, Chiu C. Tang, Robert S. Weatherup, Michael Merz, Peter Nagel, S. Schuppler, Martin Winter, Karin Kleiner
Abstract
High Resolution Image Download MS PowerPoint Slide The syntheses of Ni-poor (NCM111, LiNi 1/3 Co 1/3 Mn 1/3 O 2 ) and Ni-rich (NCM811 LiNi 0.8 Co 0.1 Mn 0.1 O 2 ) lithium transition-metal oxides (space group R 3̅m) from hydroxide precursors (Ni 1/3 Co 1/3 Mn 1/3 (OH) 2, Ni 0.8 Co 0.1 Mn 0.1 (OH) 2 ) are investigated using in situ synchrotron powder diffraction and near-edge X-ray absorption fine structure spectroscopy. The development of the layered structure of these two cathode materials proceeds via two utterly different reaction mechanisms. While the synthesis of NCM811 involves a rock salt-type intermediate phase, NCM111 reveals a layered structure throughout the entire synthesis. Moreover, the necessity and the impact of a preannealing step and a high-temperature holding step are discussed.