Uncommon Behavior of Li Doping Suppresses Oxygen Redox in P2-Type Manganese-Rich Sodium Cathodes

Biwei Xiao; Xiang Liu; Xi Chen; Gi-Hyeok Lee; Miao Song; Xin Yang; Fred Omenya; David M Reed; Vincent Sprenkle; Yang Ren; Cheng-Jun Sun; Wanli Yang; Khalil Amine; Xin Li; Guiliang Xu; Xiaolin Li

doi:10.1002/adma.202107141

Uncommon Behavior of Li Doping Suppresses Oxygen Redox in P2-Type Manganese-Rich Sodium Cathodes

Adv Mater. 2021 Dec;33(52):e2107141. doi: 10.1002/adma.202107141. Epub 2021 Oct 19.

Authors

Biwei Xiao¹, Xiang Liu², Xi Chen³, Gi-Hyeok Lee^{4

5}, Miao Song⁶, Xin Yang¹, Fred Omenya¹, David M Reed¹, Vincent Sprenkle¹, Yang Ren⁷, Cheng-Jun Sun⁷, Wanli Yang⁴, Khalil Amine^{2

8}, Xin Li³, Guiliang Xu², Xiaolin Li¹

Affiliations

¹ Energy & Environment Directorate, Pacific Northwest National Laboratory, Richland, WA, 99352, USA.
² Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, IL, 60439, USA.
³ John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, 02138, USA.
⁴ Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
⁵ Department of Materials Science and Engineering, Dongguk University, Seoul, 04620, Republic of Korea.
⁶ Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, 99352, USA.
⁷ X-ray science division, Argonne National Laboratory, Lemont, IL, 60439, USA.
⁸ Materials Science and Engineering, Stanford University, Stanford, CA, 94305, USA.

PMID: 34632654
DOI: 10.1002/adma.202107141

Abstract

Utilizing both cationic and anionic oxygen redox reactions is regarded as an important approach to exploit high-capacity layered cathode materials with earth abundant elements. It has been popular strategies to effectively elevate the oxygen redox activities by Li-doping to introduce unhybridized O 2p orbitals in Na_x MnO₂ -based chemistries or enabling high covalency transition metals in P2-Na_0.66 Mn_x TM_1- _x O₂ (TM = Fe, Cu, Ni) materials. Here, the effect of Li doping on regulating the oxygen redox activities P2-structured Na_0.66 Ni_0.25 Mn_0.75 O₂ materials is investigated. Systematic X-ray characterizations and ab initio simulations have shown that the doped Li has uncommon behavior in modulating the density of states of the neighboring Ni, Mn, and O, leading to the suppression of the existing oxygen and Mn redox reactivities and the promotion of the Ni redox. The findings provide a complementary scenario to current oxygen redox mechanisms and shed lights on developing new routes for high-performance cathodes.

Keywords: Li doping; cationic reactivity; layered cathodes; oxygen redox reactivity.

Abstract

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