%0 Journal Article
%A Liu, Haidong
%A Zhang, Xiaofei
%A He, Xin
%A Senyshyn, Anatoliy
%A Wilken, Andrea
%A Zhou, Dong
%A Fromm, Olga
%A Niehoff, Philip
%A Yan, Bo
%A Li, Jinke
%A Muehlbauer, Martin
%A Wang, Jun
%A Schumacher, Gerhard
%A Paillard, Elie
%A Winter, Martin
%A Li, Jie
%T Truncated Octahedral High-Voltage Spinel LiNi 0.5 Mn 1.5 O 4 Cathode Materials for Lithium Ion Batteries: Positive Influences of Ni/Mn Disordering and Oxygen Vacancies
%J Journal of the Electrochemical Society
%V 165
%N 9
%@ 1945-7111
%C Pennington, NJ
%I Electrochemical Soc.
%M FZJ-2019-03299
%P A1886 - A1896
%D 2018
%X Micron-sized truncated octahedral LiNi0.5Mn1.5O4 (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 Mn3+. 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.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000440924800040
%R 10.1149/2.1241809jes
%U https://juser.fz-juelich.de/record/863205