A Liquid and Waste-free Method for Preparing Single Crystal Positive Electrode Materials for Li-ion Batteries

• Published in: Journal of the Electrochemical Society 2023-07, Vol.170 (7), p.70515
• Main Authors: Zhang, Ning, Yu, Haifeng, Murphy, Aidan, Garayt, Matthew, Yu, Svena, Rathore, Divya, Leontowich, Adam, Bond, Toby, Kim, Chang-Yong, Dahn, J. R.
• Format: Article
• Language: English
• ISSN: 0013-4651; 1945-7111
• DOI: 10.1149/1945-7111/ace4f7

Nickel-rich layered positive electrode materials are normally made by a “co-precipitation-sintering” method. Mixed transition metal hydroxides called “precursors” are prepared by co-precipitation to ensure homogeneous cation mixing at the atomic level and to create spherical particles which ensure high-performance poly-crystalline materials. Single crystal materials, which show better capacity retention in long-term cycling can be made from the same mixed transition metal hydroxide precursors by sintering at a higher temperature which inevitably destroys the spherical morphology present in the initial precursors. Here we describe a method for single crystal positive electrode material production which we call “all-dry synthesis” since it does not require the use of any liquid and creates no waste unlike the co-precipitation method. The exemplary reaction between Ni, MnCO 3, and LiOH·H 2 O was studied in situ by synchrotron XRD in order to define a proper heating scheme for the all-dry process. The crystal structure, particle morphology, surface residual impurities, and electrochemical performance of materials prepared by the “all-dry synthesis” method are equivalent to or even better than those of materials made using a conventional co-precipitation method.