TY - JOUR
T1 - Thermal stability in the blended lithium manganese oxide - Lithium nickel cobalt manganese oxide cathode materials
T2 - An in situ time-resolved X-Ray diffraction and mass spectroscopy study
AU - Hu, Enyuan
AU - Bak, Seong Min
AU - Senanayake, Sanjaya D.
AU - Yang, Xiao Qing
AU - Nam, Kyung Wan
AU - Zhang, Lulu
AU - Shao, Minhua
N1 - Publisher Copyright:
© 2014 Elsevier B.V. All rights reserved.
PY - 2015/3/1
Y1 - 2015/3/1
N2 - Thermal stabilities of a series of blended LiMn2O4 (LMO)eLiNi1/3Co1/3Mn1/3O2 (NCM) cathode materials with different weight ratios were studied by in situ time-resolved X-ray diffraction (XRD) combined with mass spectroscopy in the temperature range of 25 °C-580 °C under helium atmosphere. Upon heating, the electrochemically delithiated LMO changed into Mn3O4 phase at around 250 °C. Formation of MnO with rock-salt structure started at 520 °C. This observation is in contrast to the previous report for chemically delithiated LMO in air, in which a process of λ-MnO2 transforming to β-MnO2 was observed. Oxygen peak was not observed in all cases, presumably as a result of either consumption by the carbon or detection limit. CO2 profile correlates well with the phase transition and indirectly suggests the oxygen release of the cathode. Introducing NCM into LMO has two effects: first, it makes the high temperature rock-salt phase formation more complicated with more peaks in CO2 profile due to different MO (M = Ni, Mn, Co) phases; secondly, the onset temperature of CO2 release is lowered, implying lowered oxygen release temperature. Upon heating, XRD patterns indicate the NCM part reacts first, followed by the LMO part. This confirms the better thermal stability of LMO over NCM.
AB - Thermal stabilities of a series of blended LiMn2O4 (LMO)eLiNi1/3Co1/3Mn1/3O2 (NCM) cathode materials with different weight ratios were studied by in situ time-resolved X-ray diffraction (XRD) combined with mass spectroscopy in the temperature range of 25 °C-580 °C under helium atmosphere. Upon heating, the electrochemically delithiated LMO changed into Mn3O4 phase at around 250 °C. Formation of MnO with rock-salt structure started at 520 °C. This observation is in contrast to the previous report for chemically delithiated LMO in air, in which a process of λ-MnO2 transforming to β-MnO2 was observed. Oxygen peak was not observed in all cases, presumably as a result of either consumption by the carbon or detection limit. CO2 profile correlates well with the phase transition and indirectly suggests the oxygen release of the cathode. Introducing NCM into LMO has two effects: first, it makes the high temperature rock-salt phase formation more complicated with more peaks in CO2 profile due to different MO (M = Ni, Mn, Co) phases; secondly, the onset temperature of CO2 release is lowered, implying lowered oxygen release temperature. Upon heating, XRD patterns indicate the NCM part reacts first, followed by the LMO part. This confirms the better thermal stability of LMO over NCM.
KW - Gas evolution
KW - Lithium-ion batteries
KW - Phase transformation
KW - Structural evolution
KW - Thermal stability
UR - http://www.scopus.com/inward/record.url?scp=84918518657&partnerID=8YFLogxK
U2 - 10.1016/j.jpowsour.2014.12.015
DO - 10.1016/j.jpowsour.2014.12.015
M3 - Article
AN - SCOPUS:84918518657
SN - 0378-7753
VL - 277
SP - 193
EP - 197
JO - Journal of Power Sources
JF - Journal of Power Sources
ER -