Truncated Octahedral High-Voltage Spinel LiNi0.5Mn1.5O4 Cathode Materials for Lithium Ion Batteries: Positive Influences of Ni/Mn Disordering and Oxygen Vacancies. Issue 9 (20th June 2018)

• Record Type: Journal Article
• Authors: Liu, Haidong; Zhang, Xiaofei; He, Xin; Senyshyn, Anatoliy; Wilken, Andrea; Zhou, Dong; Fromm, Olga; Niehoff, Philip; Yan, Bo; Li, Jinke; Muehlbauer, Martin; Wang, Jun; Schumacher, Gerhard; Paillard, Elie; Winter, Martin; Li, Jie
• Is Part Of: Journal of the Electrochemical Society. Volume 165:Issue 9(2018)
• Page Start: A1886
• Page End: A1896
• Publication Date: 2018-06-20
• Subjects: LiNi0.5Mn1.5O4 -- Ni/Mn disordering -- oxygen vacancies; Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/2.1241809jes
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : Micron-sized truncated octahedral LiNi0.5 Mn1.5 O4 (LNMO) samples with different degrees of Ni/Mn disordering have been obtained by controlling the synthesis conditions, such as calcination atmosphere (O2 and air), cooling rate or additional annealing step. The influences of Ni/Mn disordering on the physical properties and electrochemical performance of the truncated octahedral LNMO samples have been systematically investigated. The analyses of thermogravimetry, X-ray photoelectron spectroscopy, X-ray diffraction, powder neutron diffraction, Raman spectroscopy and X-ray absorption spectroscopy reveal that the occurrence and degree of Ni/Mn disordering are closely related with the formation of oxygen vacancies and presence of Mn 3+ . Slow cooling rate and post-annealing can result in low degrees of Ni/Mn disordering and oxygen vacancies. Electrochemical measurements show that Ni/Mn disordering and oxygen vacancies have no obvious effect on the rate capability since all LNMO samples share a truncated octahedral morphology with the exposed {100} surfaces. However, they play significant roles in improving long-term cycling stability, especially at the elevated temperature of 60°C. This work suggests that the electrochemical performance of LNMO with optimized truncated morphology can be further enhanced through tuning the degrees of Ni/Mn disordering and oxygen vacancies.