Journal
ADVANCED FUNCTIONAL MATERIALS
Volume 29, Issue 23, Pages -Publisher
WILEY-V C H VERLAG GMBH
DOI: 10.1002/adfm.201901110
Keywords
cathode surface design; DFT; AIMD modeling; graphene-coating; in situ TEM; LiCoO2 oxygen release; thermal degradation
Categories
Funding
- National Science Foundation [CMMI 1619743]
- U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy (EERE), as part of the Battery 500 Consortium [DE-EE0008210]
- MRI-R2 grant from the National Science Foundation [DMR-0959470]
- National Science Foundation DMREF Grant [1729420]
- U. S. Department of Energy (DOE), Office of Energy Efficiency and Renewable Energy, Vehicle Technologies Office
- DOE Office of Science [DE-AC02-06CH11357]
Ask authors/readers for more resources
LiCoO2 is a prime example of widely used cathodes that suffer from the structural/thermal instability issues that lead to the release of their lattice oxygen under nonequilibrium conditions and safety concerns in Li-ion batteries. Here, it is shown that an atomically thin layer of reduced graphene oxide can suppress oxygen release from LixCoO2 particles and improve their structural stability. Electrochemical cycling, differential electrochemical mass spectroscopy, differential scanning calorimetry, and in situ heating transmission electron microscopy are performed to characterize the effectiveness of the graphene-coating on the abusive tolerance of LixCoO2. Electrochemical cycling mass spectroscopy results suggest that oxygen release is hindered at high cutoff voltage cycling when the cathode is coated with reduced graphene oxide. Thermal analysis, in situ heating transmission electron microscopy, and electron energy loss spectroscopy results show that the reduction of Co species from the graphene-coated samples is delayed when compared with bare cathodes. Finally, density functional theory and ab initio molecular dynamics calculations show that the rGO layers could suppress O-2 formation more effectively due to the strong C-O-cathode bond formation at the interface of rGO/LCO where low coordination oxygens exist. This investigation uncovers a reliable approach for hindering the oxygen release reaction and improving the thermal stability of battery cathodes.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available