TY - JOUR
T1 - Effect of ambient storage on the degradation of ni-rich positive electrode materials (NMC811) for li-ion batteries
AU - Jung, Roland
AU - Morasch, Robert
AU - Karayaylali, Pinar
AU - Phillips, Katherine
AU - Maglia, Filippo
AU - Stinner, Christoph
AU - Shao-Horn, Yang
AU - Gasteiger, Hubert A.
N1 - Funding Information:
The authors thank BMW AG for the financial support of this work. Umicore is greatly acknowledged for supplying the NMC materials. R.J. thanks TUM-IAS for their support in the frame of the Rudolf-Diesel Fellowship of Dr. Peter Lamp. This work made use of the MRSEC Shared Experimental Facilities at MIT, supported by the National Science Foundation under award number DMR-1419807.
PY - 2018
Y1 - 2018
N2 - Layered LiNi0.8Mn0.1Co0.1O2 (NMC811) is one of the high-energy positive electrode (cathode) materials for next generation Li-ion batteries. However, compared to the structurally similar LiNi1/3Mn1/3Co1/3O2 (NMC111), it can suffer from a shorter lifetime due to its higher surface reactivity. This work studied and compared the formation of surface contaminations on NMC811 and NMC111 when stored under ambient conditions using electrochemical cycling, Raman spectroscopy, and X-ray photoelectron spectroscopy. NMC811 was found to develop a surface layer of up to ∼10 nm thickness that was mostly composed of nickel carbonate species mixed with minor quantities of hydroxide and water after ambient storage for 1 year, while no significant changes were observed on the NMC111 surface. The amount of carbonate species was quantified by gas chromatographic (GC) detection of carbon dioxide generated when the NMC particles were dispersed in hydrochloric acid. Surface impurity species formed on NMC811 upon ambient storage not only lead to a significant delithiation voltage peak in the first charge, but also markedly reduce the cycling stability of NMC811-graphite cells due to significantly growing polarization of the NMC811 electrode.
AB - Layered LiNi0.8Mn0.1Co0.1O2 (NMC811) is one of the high-energy positive electrode (cathode) materials for next generation Li-ion batteries. However, compared to the structurally similar LiNi1/3Mn1/3Co1/3O2 (NMC111), it can suffer from a shorter lifetime due to its higher surface reactivity. This work studied and compared the formation of surface contaminations on NMC811 and NMC111 when stored under ambient conditions using electrochemical cycling, Raman spectroscopy, and X-ray photoelectron spectroscopy. NMC811 was found to develop a surface layer of up to ∼10 nm thickness that was mostly composed of nickel carbonate species mixed with minor quantities of hydroxide and water after ambient storage for 1 year, while no significant changes were observed on the NMC111 surface. The amount of carbonate species was quantified by gas chromatographic (GC) detection of carbon dioxide generated when the NMC particles were dispersed in hydrochloric acid. Surface impurity species formed on NMC811 upon ambient storage not only lead to a significant delithiation voltage peak in the first charge, but also markedly reduce the cycling stability of NMC811-graphite cells due to significantly growing polarization of the NMC811 electrode.
UR - http://www.scopus.com/inward/record.url?scp=85042097421&partnerID=8YFLogxK
U2 - 10.1149/2.0401802jes
DO - 10.1149/2.0401802jes
M3 - Article
AN - SCOPUS:85042097421
SN - 0013-4651
VL - 165
SP - A132-A141
JO - Journal of the Electrochemical Society
JF - Journal of the Electrochemical Society
IS - 2
ER -
