Highly reversible oxygen redox in layered compounds enabled by surface polyanions
Journal Article
·
· Nature Communications
- Harbin Inst. of Technology (China); Univ. of Texas, Austin, TX (United States)
- Harbin Inst. of Technology (China)
- Chongqing Univ. (China)
- Harbin Inst. of Technology, Weihai (China)
- Univ. of Texas, Austin, TX (United States); Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Univ. of Texas, Austin, TX (United States)
Oxygen-anion redox in lithium-rich layered oxides can boost the capacity of lithium-ion battery cathodes. However, the over-oxidation of oxygen at highly charged states aggravates irreversible structure changes and deteriorates cycle performance. Here, we investigate the mechanism of surface degradation caused by oxygen oxidation and the kinetics of surface reconstruction. Considering Li2MnO3, we show through density functional theory calculations that a high energy orbital (lO2p’) at under-coordinated surface oxygen prefers over-oxidation over bulk oxygen, and that surface oxygen release is then kinetically favored during charging. We use a simple strategy of turning under-coordinated surface oxygen into polyanionic (SO4)2-, and show that these groups stabilize the surface of Li2MnO3 by depressing gas release and side reactions with the electrolyte. Experimental validation on Li1.2Ni0.2Mn0.6O2 shows that sulfur deposition enhances stability of the cathode with 99.0% capacity remaining (194 mA h g-1) after 100 cycles at 1 C. Our work reveals a promising surface treatment to address the instability of highly charged layered cathode materials.
- Research Organization:
- Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
- Sponsoring Organization:
- USDOE National Nuclear Security Administration (NNSA)
- Grant/Contract Number:
- AC52-07NA27344
- OSTI ID:
- 1734597
- Report Number(s):
- LLNL-JRNL--795628; 995477
- Journal Information:
- Nature Communications, Journal Name: Nature Communications Journal Issue: 1 Vol. 11; ISSN 2041-1723
- Publisher:
- Nature Publishing GroupCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Similar Records
Quantifying the Capacity Contributions during Activation of Li2MnO3
Li{sub 2}O removal from Li{sub 5}FeO{sub 4} - a cathode precursor for lithium-ion batteries.
Tuning Oxygen Redox Reaction through the Inductive Effect with Proton Insertion in Li-Rich Oxides
Journal Article
·
Mon Jan 27 00:00:00 UTC 2020
· ACS Energy Letters
·
OSTI ID:1596994
Li{sub 2}O removal from Li{sub 5}FeO{sub 4} - a cathode precursor for lithium-ion batteries.
Journal Article
·
Tue Feb 09 04:00:00 UTC 2010
· Chem. Mater.
·
OSTI ID:973035
Tuning Oxygen Redox Reaction through the Inductive Effect with Proton Insertion in Li-Rich Oxides
Journal Article
·
Tue Jan 21 00:00:00 UTC 2020
· ACS Applied Materials and Interfaces
·
OSTI ID:1601225