The role of cobalt deficiency on the crystal structure, surface chemistry, and electrochemical performance of Ni-rich layered LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM811) positive electrode materials was experimentally studied possibly for the first time. We synthesized pristine and cobalt-deficient NCM811 samples by solid-state reaction. Using a variety of characterization techniques and electrochemical measurements, we show that cobalt nonstoichiometry can suppress Ni 2+ /Li + cation mixing, but can simultaneously promote the formation of oxygen vacancies, leading to rapid capacity fade and inferior rate capability compared to pristine NCM811. This study provides new insights into the effects of cobalt deficiency on the cation mixing and electrochemical performance of a Ni-rich layered NCM compound.
|Number of pages||8|
|Journal||ACS Applied Materials and Interfaces|
|State||Published - Jan 9 2019|
Bibliographical noteFunding Information:
We acknowledge the support from US National Science Foundation Award (#1355438, Powering the Kentucky Bioeconomy for a Sustainable Future). We are grateful for the partial financial support provided by the Department of Chemical and Materials Engineering at the University of Kentucky. We would like to thank Long Zhang for XPS measurements, Dr. Dali Qian for help with TEM, and Andrew Meyer for proofreading the manuscript.
© 2018 American Chemical Society.
- Ni-rich NCM
- cation mixing
- cobalt deficiency
- positive electrode
- surface oxygen defects
ASJC Scopus subject areas
- Materials Science (all)