Enhancing reversibility of LiNi0.5Mn1.5O4 by regulating surface oxygen deficiency

Bibliographic Details
Title: Enhancing reversibility of LiNi0.5Mn1.5O4 by regulating surface oxygen deficiency
Authors: Dandan Wang, Cong Gao, Xuefeng Zhou, Shang Peng, Mingxue Tang, Yonggang Wang, Lujun Huang, Wenge Yang, Xiang Gao
Source: Carbon Energy, Vol 5, Iss 11, Pp n/a-n/a (2023)
Publisher Information: Wiley, 2023.
Publication Year: 2023
Collection: LCC:Production of electric energy or power. Powerplants. Central stations
Subject Terms: electrochemical performance, LiNi0.5Mn1.5O4, lithium‐ion battery, oxygen vacancies, surface reconstruction, Production of electric energy or power. Powerplants. Central stations, TK1001-1841
More Details: Abstract Oxygen deficiency has crucial effects on the crystal structure and electrochemical performance of spinel oxide lithium electrode materials such as LiNi0.5Mn1.5O4 (LNMO) cathode. In particular, the oxygen stoichiometry on the crystal surface differs from that on the crystal interior in LNMO. The detection of local oxygen loss in LNMO and its correlation with the crystal structure and the cycling stability of LNMO remain challenging. In this study, the effect of oxygen deficiency in LNMO controlled by sintering temperature on the surface crystal structure and electrochemical performance of LNMO is comprehensively investigated. The high concentration of oxygen vacancies segregates at the surface regions of LNMO forming a thin rock‐salt and/or deficient spinel surface layer. The atomic‐level surface structure reconstruction was demonstrated by annular dark‐field and annular bright‐field techniques. For the synthesis of LNMO, the higher sintering temperature results in higher crystallinity but the higher oxygen deficiency in LNMO. The high crystallinity of LNMO would increase the thermal stability of LNMO cathodes while the high content of oxygen deficiency would decrease the surface structural stability of LNMO. Therefore, the LNMO sintered at a medium temperature of 850°C achieved the best capacity retention. The results suggest a competitive function mechanism between oxygen stoichiometry and the crystallinity of LNMO on the cycling performance of LNMO.
Document Type: article
File Description: electronic resource
Language: English
ISSN: 2637-9368
Relation: https://doaj.org/toc/2637-9368
DOI: 10.1002/cey2.338
Access URL: https://doaj.org/article/dc79902ec8434bed8979fe18c9743704
Accession Number: edsdoj.79902ec8434bed8979fe18c9743704
Database: Directory of Open Access Journals
More Details
ISSN:26379368
DOI:10.1002/cey2.338
Published in:Carbon Energy
Language:English