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

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....

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Main Authors: Dandan Wang, Cong Gao, Xuefeng Zhou, Shang Peng, Mingxue Tang, Yonggang Wang, Lujun Huang, Wenge Yang, Xiang Gao
Format: Article
Language:English
Published: Wiley 2023-11-01
Series:Carbon Energy
Subjects:
Online Access:https://doi.org/10.1002/cey2.338
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author Dandan Wang
Cong Gao
Xuefeng Zhou
Shang Peng
Mingxue Tang
Yonggang Wang
Lujun Huang
Wenge Yang
Xiang Gao
author_facet Dandan Wang
Cong Gao
Xuefeng Zhou
Shang Peng
Mingxue Tang
Yonggang Wang
Lujun Huang
Wenge Yang
Xiang Gao
author_sort Dandan Wang
collection DOAJ
description 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.
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spelling doaj.art-dc79902ec8434bed8979fe18c97437042023-11-30T13:46:05ZengWileyCarbon Energy2637-93682023-11-01511n/an/a10.1002/cey2.338Enhancing reversibility of LiNi0.5Mn1.5O4 by regulating surface oxygen deficiencyDandan Wang0Cong Gao1Xuefeng Zhou2Shang Peng3Mingxue Tang4Yonggang Wang5Lujun Huang6Wenge Yang7Xiang Gao8Center for High Pressure Science and Technology Advanced Research (HPSTAR) Beijing ChinaCenter for High Pressure Science and Technology Advanced Research (HPSTAR) Beijing ChinaCenter for High Pressure Science and Technology Advanced Research (HPSTAR) Beijing ChinaCenter for High Pressure Science and Technology Advanced Research (HPSTAR) Beijing ChinaCenter for High Pressure Science and Technology Advanced Research (HPSTAR) Beijing ChinaCenter for High Pressure Science and Technology Advanced Research (HPSTAR) Beijing ChinaSchool of Materials Science and Engineering, Harbin Institute of Technology Harbin ChinaCenter for High Pressure Science and Technology Advanced Research (HPSTAR) Beijing ChinaCenter for High Pressure Science and Technology Advanced Research (HPSTAR) Beijing ChinaAbstract 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.https://doi.org/10.1002/cey2.338electrochemical performanceLiNi0.5Mn1.5O4lithium‐ion batteryoxygen vacanciessurface reconstruction
spellingShingle Dandan Wang
Cong Gao
Xuefeng Zhou
Shang Peng
Mingxue Tang
Yonggang Wang
Lujun Huang
Wenge Yang
Xiang Gao
Enhancing reversibility of LiNi0.5Mn1.5O4 by regulating surface oxygen deficiency
Carbon Energy
electrochemical performance
LiNi0.5Mn1.5O4
lithium‐ion battery
oxygen vacancies
surface reconstruction
title Enhancing reversibility of LiNi0.5Mn1.5O4 by regulating surface oxygen deficiency
title_full Enhancing reversibility of LiNi0.5Mn1.5O4 by regulating surface oxygen deficiency
title_fullStr Enhancing reversibility of LiNi0.5Mn1.5O4 by regulating surface oxygen deficiency
title_full_unstemmed Enhancing reversibility of LiNi0.5Mn1.5O4 by regulating surface oxygen deficiency
title_short Enhancing reversibility of LiNi0.5Mn1.5O4 by regulating surface oxygen deficiency
title_sort enhancing reversibility of lini0 5mn1 5o4 by regulating surface oxygen deficiency
topic electrochemical performance
LiNi0.5Mn1.5O4
lithium‐ion battery
oxygen vacancies
surface reconstruction
url https://doi.org/10.1002/cey2.338
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