Journal
ADVANCED ENERGY MATERIALS
Volume 12, Issue 18, Pages -Publisher
WILEY-V C H VERLAG GMBH
DOI: 10.1002/aenm.202200136
Keywords
chemo-mechanical degradation; density functional theory; doping; high-nickel NCM cathodes; layered cathode materials
Categories
Funding
- Basic Science Research Program through the National Research Foundation of Korea (NRF) - Ministry of Education [2020R1A6A3A13070145]
- Center for Nanoparticle Research at Institute for Basic Science (IBS) [IBS-R006-A2]
- National Supercomputing Center [KSC-2016-C3-0069]
- National Research Foundation of Korea [2020R1A6A3A13070145] Funding Source: Korea Institute of Science & Technology Information (KISTI), National Science & Technology Information Service (NTIS)
Ask authors/readers for more resources
This study investigates the feasibility of doping strategies to improve the cycle stability of high-nickel NCM cathodes in lithium-ion batteries. A three-step screening process is used to identify effective dopants based on density functional theory calculations. The study successfully synthesizes a silicon-doped cathode with superior electrochemical performance compared to the undoped counterpart. Additionally, a comprehensive map of dopants for potential applicability is presented, providing guidance for an effective doping strategy for high-nickel NCM cathodes.
NCM-based lithium layered oxides (LiNi1-x-yCoxMnyO2) have become prevalent cathode materials in state-of-the-art lithium-ion batteries. Higher energy densities can be achieved in these materials by systematically increasing the nickel content; however, this approach commonly results in inferior cycle stability. The poor cycle retention of high-nickel NCM cathodes is generally attributed to chemo-mechanical degradation (e.g., intergranular microcracks), vulnerability to oxygen-gas evolution, and the accompanying rocksalt phase formation via cation mixing. Herein, the feasibility of doping strategies is examined to mitigate these issues and effective dopants for high-nickel NCM cathodes are theoretically identified through a stepwise pruning process based on density functional theory calculations. Specifically, a sequential three-step screening process is conducted for 38 potential dopants to scrutinize their effectiveness in mitigating chemo-mechanical lattice stress, oxygen evolution, and cation mixing at charged states. Using this process, promising dopant species are selected rationally and a silicon-doped LiNi0.92Co0.04Mn0.04O2 cathode is synthesized, which exhibits suppressed lattice expansion/contraction, fewer intergranular microcracks, and reduced rocksalt formation on the surface compared with its undoped counterpart, leading to superior electrochemical performance. Moreover, a comprehensive map of dopants regarding their potential applicability is presented, providing rational guidance for an effective doping strategy for high-nickel NCM cathodes.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available