title: Modification of Ni-Rich FCG NMC and NCA Cathodes by Atomic Layer Deposition: Preventing Surface Phase Transitions for High-Voltage Lithium-Ion Batteries.
abstract: The energy density of current lithium-ion batteries (LIBs) based on layered LiMO2 cathodes (M = Ni, Mn, Co: NMC; M = Ni, Co, Al: NCA) needs to be improved significantly in order to compete with internal combustion engines and allow for widespread implementation of electric vehicles (EVs). In this report, we show that atomic layer deposition (ALD) of titania (TiO2) and alumina (Al2O3) on Ni-rich FCG NMC and NCA active material particles could substantially improve LIB performance and allow for increased upper cutoff voltage (UCV) during charging, which delivers significantly increased specific energy utilization. Our results show that Al2O3 coating improved the NMC cycling performance by 40% and the NCA cycling performance by 34% at 1 C/-1 C with respectively 4.35 V and 4.4 V UCV in 2 Ah pouch cells. High resolution TEM/SAED structural characterization revealed that Al2O3 coatings prevented surface-initiated layered-to-spinel phase transitions in coated materials which were prevalent in uncoated materials. EIS confirmed that Al2O3-coated materials had significantly lower increase in the charge transfer component of impedance during cycling. The ability to mitigate degradation mechanisms for Ni-rich NMC and NCA illustrated in this report provides insight into a method to enable the performance of high-voltage LIBs.
authors.affiliation: Energy and Transportation Science Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA.
authors.forename: Debasish
authors.initials: D
authors.lastname: Mohanty
authors.affiliation: Energy Power Systems, LLC, Pontiac, MI, USA.
authors.forename: Kevin
authors.initials: K
authors.lastname: Dahlberg
authors.affiliation: PneumatiCoat Technologies, LLC, Broomfield, CO, USA.
authors.forename: David M
authors.initials: DM
authors.lastname: King
authors.affiliation: Energy and Transportation Science Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA.
authors.forename: Lamuel A
authors.initials: LA
authors.lastname: David
authors.affiliation: Materials Science and Technology Division, Oak Ridge National Laboratory, oak Ridge, TN, USA.
authors.forename: Athena S
authors.initials: AS
authors.lastname: Sefat
authors.affiliation: Energy and Transportation Science Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA.|Bredesen Center for Interdisciplinary Research and Graduate Education, University of Tennessee, Knoxville, TN, USA.
authors.forename: David L
authors.initials: DL
authors.lastname: Wood
authors.affiliation: Energy and Transportation Science Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA.|Bredesen Center for Interdisciplinary Research and Graduate Education, University of Tennessee, Knoxville, TN, USA.
authors.forename: Claus
authors.initials: C
authors.lastname: Daniel
authors.affiliation: Energy Power Systems, LLC, Pontiac, MI, USA.|XALT Energy, LLC, Midland, MI, USA.
authors.forename: Subhash
authors.initials: S
authors.lastname: Dhar
authors.affiliation: XALT Energy, LLC, Midland, MI, USA.
authors.forename: Vishal
authors.initials: V
authors.lastname: Mahajan
authors.affiliation: XALT Energy, LLC, Midland, MI, USA.
authors.forename: Myongjai
authors.initials: M
authors.lastname: Lee
authors.affiliation: Department of Materials Science and Engineering, University of Michigan Ann Arbor, 2300 Hayward St, Ann Arbor, MI, 48109, USA.
authors.forename: Fabio
authors.initials: F
authors.lastname: Albano