Abstract
The ageing mechanisms of C6/LiNi0.5Mn0.3Co0.2O2 batteries at various discharging currents and temperatures have systematically been investigated with electrochemical and post-mortem analyses. The irreversible capacity losses (ΔQir) at various ageing conditions are calculated on the basis of regularly determined electromotive force (EMF) curves. Two stages can be distinguished for the degradation of the storage capacity at 30 °C. The first stage includes SEI formation, cathode dissolution, etc. The second stage is related to battery polarization. The various degradation mechanisms of the individual electrodes have been distinguished by dVEMF/dQ vs Qout and dVEMF/dQ vs V plots. The Solid-Electrolyte-Interface (SEI) formation as well as the electrode degradation has been experimentally confirmed by XPS analyses. Both Ni and Mn elements are detected at the anode while Co is absent, indicating that the bonding of Co atoms is more robust in the cathode host structure. A Cathode-Electrolyte-Interface (CEI) layer is also detected at the cathode surface. The composition of the CEI layer includes Li salts, such as LiF, LiCOOR, as well as transition metal compounds like NiF2. Cathode dissolution is considered to be responsible for both the NiF2 detected at the cathode and Ni at the anode.
| Language | English |
|---|---|
| Pages | 163-174 |
| Number of pages | 12 |
| Journal | Journal of Power Sources |
| Volume | 416 |
| DOIs | |
| State | Published - 15 Mar 2019 |
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Keywords
- Electrode degradation
- Electromotive force
- Irreversible capacity loss
- Li-ion battery
- Solid-electrolyte-interphase
Cite this
}
Degradation mechanisms of C6/LiNi0.5Mn0.3Co0.2O2 Li-ion batteries unraveled by non-destructive and post-mortem methods. / Li, Dongjiang; Li, Hu; Danilov, Dmitri L.; Gao, Lu; Chen, Xiaoxuan; Zhang, Zhongru; Zhou, Jiang; Eichel, Rüdiger A.; Yang, Yong (Corresponding author); Notten, Peter H.L. (Corresponding author).
In: Journal of Power Sources, Vol. 416, 15.03.2019, p. 163-174.Research output: Contribution to journal › Article › Academic › peer-review
TY - JOUR
T1 - Degradation mechanisms of C6/LiNi0.5Mn0.3Co0.2O2 Li-ion batteries unraveled by non-destructive and post-mortem methods
AU - Li,Dongjiang
AU - Li,Hu
AU - Danilov,Dmitri L.
AU - Gao,Lu
AU - Chen,Xiaoxuan
AU - Zhang,Zhongru
AU - Zhou,Jiang
AU - Eichel,Rüdiger A.
AU - Yang,Yong
AU - Notten,Peter H.L.
PY - 2019/3/15
Y1 - 2019/3/15
N2 - The ageing mechanisms of C6/LiNi0.5Mn0.3Co0.2O2 batteries at various discharging currents and temperatures have systematically been investigated with electrochemical and post-mortem analyses. The irreversible capacity losses (ΔQir) at various ageing conditions are calculated on the basis of regularly determined electromotive force (EMF) curves. Two stages can be distinguished for the degradation of the storage capacity at 30 °C. The first stage includes SEI formation, cathode dissolution, etc. The second stage is related to battery polarization. The various degradation mechanisms of the individual electrodes have been distinguished by dVEMF/dQ vs Qout and dVEMF/dQ vs V plots. The Solid-Electrolyte-Interface (SEI) formation as well as the electrode degradation has been experimentally confirmed by XPS analyses. Both Ni and Mn elements are detected at the anode while Co is absent, indicating that the bonding of Co atoms is more robust in the cathode host structure. A Cathode-Electrolyte-Interface (CEI) layer is also detected at the cathode surface. The composition of the CEI layer includes Li salts, such as LiF, LiCOOR, as well as transition metal compounds like NiF2. Cathode dissolution is considered to be responsible for both the NiF2 detected at the cathode and Ni at the anode.
AB - The ageing mechanisms of C6/LiNi0.5Mn0.3Co0.2O2 batteries at various discharging currents and temperatures have systematically been investigated with electrochemical and post-mortem analyses. The irreversible capacity losses (ΔQir) at various ageing conditions are calculated on the basis of regularly determined electromotive force (EMF) curves. Two stages can be distinguished for the degradation of the storage capacity at 30 °C. The first stage includes SEI formation, cathode dissolution, etc. The second stage is related to battery polarization. The various degradation mechanisms of the individual electrodes have been distinguished by dVEMF/dQ vs Qout and dVEMF/dQ vs V plots. The Solid-Electrolyte-Interface (SEI) formation as well as the electrode degradation has been experimentally confirmed by XPS analyses. Both Ni and Mn elements are detected at the anode while Co is absent, indicating that the bonding of Co atoms is more robust in the cathode host structure. A Cathode-Electrolyte-Interface (CEI) layer is also detected at the cathode surface. The composition of the CEI layer includes Li salts, such as LiF, LiCOOR, as well as transition metal compounds like NiF2. Cathode dissolution is considered to be responsible for both the NiF2 detected at the cathode and Ni at the anode.
KW - Electrode degradation
KW - Electromotive force
KW - Irreversible capacity loss
KW - Li-ion battery
KW - Solid-electrolyte-interphase
UR - http://www.scopus.com/inward/record.url?scp=85061059150&partnerID=8YFLogxK
U2 - 10.1016/j.jpowsour.2019.01.083
DO - 10.1016/j.jpowsour.2019.01.083
M3 - Article
VL - 416
SP - 163
EP - 174
JO - Journal of Power Sources
T2 - Journal of Power Sources
JF - Journal of Power Sources
SN - 0378-7753
ER -