TY  - JOUR
AU  - Liu, Haidong
AU  - Zhang, Xiaofei
AU  - He, Xin
AU  - Senyshyn, Anatoliy
AU  - Wilken, Andrea
AU  - Zhou, Dong
AU  - Fromm, Olga
AU  - Niehoff, Philip
AU  - Yan, Bo
AU  - Li, Jinke
AU  - Muehlbauer, Martin
AU  - Wang, Jun
AU  - Schumacher, Gerhard
AU  - Paillard, Elie
AU  - Winter, Martin
AU  - Li, Jie
TI  - 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
JO  - Journal of the Electrochemical Society
VL  - 165
IS  - 9
SN  - 1945-7111
CY  - Pennington, NJ
PB  - Electrochemical Soc.
M1  - FZJ-2019-03299
SP  - A1886 - A1896
PY  - 2018
AB  - 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.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000440924800040
DO  - DOI:10.1149/2.1241809jes
UR  - https://juser.fz-juelich.de/record/863205
ER  -