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Investigating Surface Reactivity of a Ni-Rich Cathode Material toward CO2, H2O, and O2 Using Ambient Pressure X-ray Photoelectron Spectroscopy

Chen, Heyin ; Ericson, Tove ; Temperton, Robert H. LU ; Källquist, Ida ; Liu, Haidong ; Eads, Calley N. LU ; Mikheenkova, Anastasiia ; Andersson, Margit LU ; Kokkonen, Esko LU orcid and Brant, William R. , et al. (2023) In ACS Applied Energy Materials 6(22). p.11458-11467
Abstract

Layered Ni-rich transition metal oxide materials are considered the most promising cathodes for use in commercial Li-ion batteries. Due to their instability in air, an impurity layer forms during storage under ambient conditions, and this layer increases electrochemical polarization during charging and discharging, which ultimately leads to a lower cycling capacity. In this work, we found that storage of the LiNi0.8Mn0.1Co0.1O2 (NMC 811) material in ultrahigh vacuum (UHV) can restore the surface by reducing the amount of native carbonate species in the impurity layer. In this work, in situ soft X-ray ambient pressure photoelectron spectroscopy is used to directly follow the interaction between... (More)

Layered Ni-rich transition metal oxide materials are considered the most promising cathodes for use in commercial Li-ion batteries. Due to their instability in air, an impurity layer forms during storage under ambient conditions, and this layer increases electrochemical polarization during charging and discharging, which ultimately leads to a lower cycling capacity. In this work, we found that storage of the LiNi0.8Mn0.1Co0.1O2 (NMC 811) material in ultrahigh vacuum (UHV) can restore the surface by reducing the amount of native carbonate species in the impurity layer. In this work, in situ soft X-ray ambient pressure photoelectron spectroscopy is used to directly follow the interaction between common gases found in air and the NMC 811 surface. During gas exposure of the NMC 811 surface to pure CO2, O2, and a mixture of both pure gases, surface-adsorbed CO2 or/and O2 were detected; however, permanent changes could not be identified under UHV after the gas exposure. In contrast, a permanent increase in metal hydroxide species was observed on the sample surface following H2O vapor exposure, and an increased intensity in the carboxylate peak was observed after exposure to a mixture of CO2/O2/H2O. Thus, the irreversible degradation reaction with CO2 is triggered in the presence of H2O (on relevant time scales defined by the experiment). Additional measurements revealed that X-ray irradiation induces the formation of metal carbonate species on the NMC 811 surface under CO2 and H2O vapor pressure.

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organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
ambient pressure PES, beam effect, gas exposure, Li-ion batteries, Ni-rich NMC materials, surface degradation
in
ACS Applied Energy Materials
volume
6
issue
22
pages
10 pages
publisher
The American Chemical Society (ACS)
external identifiers
  • scopus:85178327669
ISSN
2574-0962
DOI
10.1021/acsaem.3c01621
language
English
LU publication?
yes
id
a333b33a-6fc3-4ff2-9cd2-c66cbd6a2e36
date added to LUP
2024-01-02 15:17:00
date last changed
2024-01-02 15:18:17
@article{a333b33a-6fc3-4ff2-9cd2-c66cbd6a2e36,
  abstract     = {{<p>Layered Ni-rich transition metal oxide materials are considered the most promising cathodes for use in commercial Li-ion batteries. Due to their instability in air, an impurity layer forms during storage under ambient conditions, and this layer increases electrochemical polarization during charging and discharging, which ultimately leads to a lower cycling capacity. In this work, we found that storage of the LiNi<sub>0.8</sub>Mn<sub>0.1</sub>Co<sub>0.1</sub>O<sub>2</sub> (NMC 811) material in ultrahigh vacuum (UHV) can restore the surface by reducing the amount of native carbonate species in the impurity layer. In this work, in situ soft X-ray ambient pressure photoelectron spectroscopy is used to directly follow the interaction between common gases found in air and the NMC 811 surface. During gas exposure of the NMC 811 surface to pure CO<sub>2</sub>, O<sub>2</sub>, and a mixture of both pure gases, surface-adsorbed CO<sub>2</sub> or/and O<sub>2</sub> were detected; however, permanent changes could not be identified under UHV after the gas exposure. In contrast, a permanent increase in metal hydroxide species was observed on the sample surface following H<sub>2</sub>O vapor exposure, and an increased intensity in the carboxylate peak was observed after exposure to a mixture of CO<sub>2</sub>/O<sub>2</sub>/H<sub>2</sub>O. Thus, the irreversible degradation reaction with CO<sub>2</sub> is triggered in the presence of H<sub>2</sub>O (on relevant time scales defined by the experiment). Additional measurements revealed that X-ray irradiation induces the formation of metal carbonate species on the NMC 811 surface under CO<sub>2</sub> and H<sub>2</sub>O vapor pressure.</p>}},
  author       = {{Chen, Heyin and Ericson, Tove and Temperton, Robert H. and Källquist, Ida and Liu, Haidong and Eads, Calley N. and Mikheenkova, Anastasiia and Andersson, Margit and Kokkonen, Esko and Brant, William R. and Hahlin, Maria}},
  issn         = {{2574-0962}},
  keywords     = {{ambient pressure PES; beam effect; gas exposure; Li-ion batteries; Ni-rich NMC materials; surface degradation}},
  language     = {{eng}},
  month        = {{11}},
  number       = {{22}},
  pages        = {{11458--11467}},
  publisher    = {{The American Chemical Society (ACS)}},
  series       = {{ACS Applied Energy Materials}},
  title        = {{Investigating Surface Reactivity of a Ni-Rich Cathode Material toward CO<sub>2</sub>, H<sub>2</sub>O, and O<sub>2</sub> Using Ambient Pressure X-ray Photoelectron Spectroscopy}},
  url          = {{http://dx.doi.org/10.1021/acsaem.3c01621}},
  doi          = {{10.1021/acsaem.3c01621}},
  volume       = {{6}},
  year         = {{2023}},
}