Title: Positive Role of Fluorine Impurity in Recovered LiNi_0.6Co_0.2Mn_0.2O₂ Cathode Materials

Abstract

Lithium-ion battery (LIB) recycling is considered as an important component to enable industry sustainability. A massive number of LIBs in portable electronics, electric vehicles, and grid storage will eventually end up as wastes, leading to serious economic and environmental problems. Hence, tremendous efforts have been made to improve the hydrometallurgical recycling process because it is the most promising option for handling end-of-life LIBs owing to its wide applicability, low cost, and high productivity. Despite these advantages, some extra elements (Al, Fe, C, F, and so forth) remain as impurities in the removal process and are retained in the solution, which is a great challenge to obtain high-quality cathode materials. In this work, the impacts caused by fluorine impurity on the LiNi_0.6Co_0.2Mn_0.2O₂ (NCM622) cathode are intensively investigated via hydrometallurgical coprecipitation for the first time. Our results show that up to 1 at. % fluorine impurity brings a positive influence on the recovered material due to a higher Ni²⁺ ratio on the surface of cathode particles. In addition, the presence of fluoride ions during coprecipitation could lead to the formation of holes in cathode particles, which improves the rate capability and cyclability dramatically. Compared to the virgin material, the capacity of themore » NCM622 material with 0.2 at. % fluorine impurity is boosted by ~8% (167.7 mA h/g) with a remarkable capacity retention of 98.0% after 100 cycles at 0.33 C. Besides, the cathode with 0.2 at. % fluorine impurity shows a far better rate performance, especially at high rates (~7% increased at 5 C) than that of virgin. Furthermore, these results convince that a low concentration of fluorine impurity is desirable in the hydrometallurgical recycling process. More importantly, this study offers implications in the design of high-performance NCM622 cathode materials via coprecipitation production with ion doping in the near future.« less

Authors:

Zheng, Yadong  ^[1];

• Search DOE PAGES for author "Zheng, Yadong"
• Search DOE PAGES for ORCID "0000-0003-4421-9859"

Zhang, Ruihan ^[1]; Vanaphuti, Panawan  ^[1];

• Search DOE PAGES for author "Vanaphuti, Panawan"
• Search DOE PAGES for ORCID "0000-0002-8152-1339"

Liu, Yangtao ^[1]; Yang, Zhenzhen ^[2]; Wang, Yan  ^[1]

• Search DOE PAGES for author "Wang, Yan"
• Search DOE PAGES for ORCID "0000-0003-1060-2956"

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+ Show Author Affiliations

1. Worcester Polytechnic Institute, MA (United States)
2. Argonne National Lab. (ANL), Lemont, IL (United States)

Publication Date:

Fri Nov 19 00:00:00 EST 2021

Research Org.:

Argonne National Lab. (ANL), Argonne, IL (United States)

Sponsoring Org.:

USDOE Office of Energy Efficiency and Renewable Energy (EERE)

OSTI Identifier:

1838890

Grant/Contract Number:  

AC02-06CH11357

Resource Type:

Accepted Manuscript

Journal Name:

ACS Applied Materials and Interfaces

Additional Journal Information:

Journal Volume: 13; Journal Issue: 48; Journal ID: ISSN 1944-8244

Publisher:

American Chemical Society (ACS)

Country of Publication:

United States

Language:

English

Subject:

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; LiNi0.6Co0.2Mn0.2O2 (NCM622) cathode; electrochemistry; fluorine impurity; hydrometallurgical recycling; lithium-ion batteries; impurities; materials; electrodes; fluorine; ions