2-12.Fine-tuning chemistry and local structure in grain boundaries of Ni-rich layered cathode for high cycling and rate performance
Qi Liu
Department of Physics, City University of Hong Kong
Abstract: Here, we develop an approach to improve the cycling and rate performance of LiNi0.8Co0.1Mn0.1O2 (NCM811), a typical Ni-rich layered cathode material, by regulating its grain boundaries, for which the primary grains are attached with Ni3+-rich boundaries spreading over a secondary particle. Local structural and chemical investigations reveal that the NiO6 octahedrons are distorted in the grain boundaries, induced by the Jahn-Teller effect of low-spin Ni3+ states. Our approach provides an example of optimizing Ni-rich cathode material with grain-boundary engineering, which could be expanded to widespread battery researches.
Keywords: synchrotron; NCM 811; Jahn-Teller effect; Li ion batteries
Dr. Liu currently work as an assistant professor at department of physics in City university of Hong Kong. He obtained his Ph.D. degree in Mechanical Engineering from Purdue University in 2014. After that, Dr Liu performed his postdoc training at Argonne National Lab. His research has been focusing on “Fundamental investigation of phase transformative materials for energy application”. Through conducting a series of cutting-edge research, he has equipped himself with expertise in a large variety of synchrotron X-ray physics, materials synthesis and characterization techniques. Particularly, he is a leading expert in utilizing multiple synchrotron X-ray techniques for fundamental studies of materials in energy application. In addition, he has considerable experience in fabricating and testing prototype batteries. To date, He has already published 50+ journal articles such as Nature, Nature Energy, and Nature Comm et al.
Email: qiliu63@cityu.edu.hk.