A Surface Se‐Substituted LiCo[O 2− δ Se δ ] Cathode with Ultrastable High‐Voltage Cycling in Pouch Full‐Cells
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5.35 MB
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Author(s)
Zhu, Zhi
Wang, Hua
Li, Yao
Gao, Rui
Xiao, Xianghui
Yu, Qipeng
Wang, Chao
Waluyo, Iradwikanari
Ding, Jiaxin
Hunt, Adrian
Date Issued
2020
Journal
Advanced Materials
Publisher
Wiley
Citation
Zhu, Zhi, Wang, Hua, Li, Yao, Gao, Rui, Xiao, Xianghui et al. 2020. "A Surface Se‐Substituted LiCo[O 2− δ Se δ ] Cathode with Ultrastable High‐Voltage Cycling in Pouch Full‐Cells." Advanced Materials, 32 (50).
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Author's final manuscript
Abstract
© 2020 Wiley-VCH GmbH Cycling LiCoO2 to above 4.5 V for higher capacity is enticing; however, hybrid O anion- and Co cation-redox (HACR) at high voltages facilitates intrinsic Oα− (α < 2) migration, causing oxygen loss, phase collapse, and electrolyte decomposition that severely degrade the battery cyclability. Hereby, commercial LiCoO2 particles are operando treated with selenium, a well-known anti-aging element to capture oxygen-radicals in the human body, showing an “anti-aging” effect in high-voltage battery cycling and successfully stopping the escape of oxygen from LiCoO2 even when the cathode is cycled to 4.62 V. Ab initio calculation and soft X-ray absorption spectroscopy analysis suggest that during deep charging, the precoated Se will initially substitute some mobile Oα− at the charged LiCoO2 surface, transplanting the pumped charges from Oα− and reducing it back to O2− to stabilize the oxygen lattice in prolonged cycling. As a result, the material retains 80% and 77% of its capacity after 450 and 550 cycles under 100 mA g−1 in 4.57 V pouch full-cells matched with a graphite anode and an ultralean electrolyte (2 g Ah−1).
MIT Department
Massachusetts Institute of Technology. Department of Nuclear Science and Engineering
Massachusetts Institute of Technology. Department of Materials Science and Engineering
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DOI of Published Version
https://doi.org/10.1002/ADMA.202005182
