Florian Schipper1, Hana Bouzaglo1, Mudit Dixit1, Evan M. Erickson1, Tina Weigel2, M. Talianker3, Judith Grinblat1, L. Burstein4, Michael A. Schmidt5, Jordan Lampert5, Christoph Erk5, Boris Markovsky1, Dan Thomas Major1, Doron Aurbach1
1Department of Chemistry, Faculty of Exact Sciences, Bar-Ilan University, Ramat-Gan, 5290002, Israel
2TU Bergakademie Freiberg, Institute of Experimental Physics, Leipziger Str. 23, 09599 Freiberg, Germany
3Department of Materials Engineering, Ben Gurion University of the Negev, Beer-Sheva, 84105 Israel
4Wolfson Applied Materials Research Center Tel-Aviv University Tel Aviv 69978 Israel
5GCN/E BASF SE, Ludwigshafen am Rhein, 67056 Germany
Tóm tắt
AbstractOne of the major hurdles of Ni‐rich cathode materials Li1+x(NixCozMnz)wO2, y > 0.5 for lithium‐ion batteries is their low cycling stability especially for compositions with Ni ≥ 60%, which suffer from severe capacity fading and impedance increase during cycling at elevated temperatures (e.g., 45 °C). Two promising surface and structural modifications of these materials to alleviate the above drawback are (1) coatings by electrochemically inert inorganic compounds (e.g., ZrO2) or (2) lattice doping by cations like Zr4+, Al3+, Mg2+, etc. This paper demonstrates the enhanced electrochemical behavior of Ni‐rich material LiNi0.8Co0.1Mn0.1O2 (NCM811) coated with a thin ZrO2 layer. The coating is produced by an easy and scalable wet chemical approach followed by annealing the material at ≥700 °C under oxygen that results in Zr doping. It is established that some ZrO2 remains even after annealing at ≥800 °C as a surface layer on NCM811. The main finding of this work is the enhanced cycling stability and lower impedance of the coated/doped NCM811 that can be attributed to a synergetic effect of the ZrO2 coating in combination with a zirconium doping.
