Coexistence of (O-2)(n-) and Trapped Molecular O-2 as the Oxidized Species in P2-Type Sodium 3d Layered Oxide and Stable Interface Enabled by Highly Fluorinated Electrolyte

doi:10.1021/jacs.1c08614

	Coexistence of (O-2)(n-) and Trapped Molecular O-2 as the Oxidized Species in P2-Type Sodium 3d Layered Oxide and Stable Interface Enabled by Highly Fluorinated Electrolyte
	Zhao, Chong 2; Li, Chao 2; Liu, Hui 2; Qiu, Qing 2; Geng, Fushan 2; Shen, Ming 2; Tong, Wei 1; Li, Jingxin 1; Hu, Bingwen 2
刊名	JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
	2021-11-10
卷号	143
ISSN号	0002-7863
DOI	10.1021/jacs.1c08614
通讯作者	Li, Chao(lchao@phy.ecnu.edu.cn) ; Hu, Bingwen(bwhu@phy.ecnu.edu.cn)
英文摘要	The interface stability of cathode/electrolyte for Na-ion layered oxides is tightly related to the oxidized species formed during the electrochemical process. Herein, we for the first time decipher the coexistence of (O-2)(n-) and trapped molecular O-2 in the (de)sodiation process of P2-Na-0.66[Li0.22Mn0.78]O-2 by using advanced electron paramagnetic resonance (EPR) spectroscopy. An unstable interface of cathode/electrolyte can thus be envisaged with conventional carbonate electrolyte due to the high reactivity of the oxidized O species. We therefore introduce a highly fluorinated electrolyte to tentatively construct a stable and protective interface between P2-Na-0.66[Li0.22Mn0.78]O-2 and the electrolyte. As expected, an even and robust NaF-rich cathode-electrolyte interphase (CEI) film is formed in the highly fluorinated electrolyte, in sharp contrast to the nonuniform and friable organic-rich CEI formed in the conventional lowly fluorinated electrolyte. The in situ formed fluorinated CEI film can significantly mitigate the local structural degeneration of P2-Na-0.66[Li0.22Mn0.78]O-2 by refraining the irreversible Li/Mn dissolutions and O-2 release, endowing a highly reversible oxygen redox reaction. Resultantly, P2-Na-0.66[Li0.22Mn0.78]O-2 in highly fluorinated electrolyte achieves a high Coulombic efficiency (CE) of >99% and an impressive cycling stability in the voltage range of 2.0-4.5 V (vs Na+/Na) under room temperature (147.6 mAh g(-1), 100 cycles) and at 45 degrees C (142.5 mAh g(-1), 100 cycles). This study highlights the profound impact of oxidized oxygen species on the interfacial stability of cathode/electrolyte and carves a new path for building stable interface and enabling highly stable oxygen redox reaction.
资助项目	National Natural Science Foundation of China[21902049] ; National Natural Science Foundation of China[21872055] ; Shanghai Sailing Program[19YF1413000] ; Shanghai Key Laboratory of Magnetic Resonance ; Steady High Magnetic Field Facilities of High Magnetic Field Laboratory (CAS)
WOS关键词	ANIONIC REDOX ACTIVITY ; SOLID-STATE NMR ; OXYGEN-REDOX ; LI-ION ; STRUCTURAL STABILITY ; CATHODE MATERIALS ; ENERGY DENSITY ; HIGH-CAPACITY ; INTERCALATION ; BATTERIES
WOS研究方向	Chemistry
语种	英语
出版者	AMER CHEMICAL SOC
WOS记录号	WOS:000718279300032
资助机构	National Natural Science Foundation of China ; Shanghai Sailing Program ; Shanghai Key Laboratory of Magnetic Resonance ; Steady High Magnetic Field Facilities of High Magnetic Field Laboratory (CAS)
内容类型	期刊论文
源URL	[http://ir.hfcas.ac.cn:8080/handle/334002/126634]
专题	中国科学院合肥物质科学研究院
通讯作者	Li, Chao; Hu, Bingwen
作者单位	1.Chinese Acad Sci, Anhui Key Lab Condensed Matter Phys Extreme Condi, High Magnet Field Lab, Hefei 230031, Peoples R China 2.East China Normal Univ, Sch Phys & Elect Sci, Shanghai Key Lab Magnet Resonance, State Key Lab Precis Spect, Shanghai 200241, Peoples R China
推荐引用方式 GB/T 7714	Zhao, Chong,Li, Chao,Liu, Hui,et al. Coexistence of (O-2)(n-) and Trapped Molecular O-2 as the Oxidized Species in P2-Type Sodium 3d Layered Oxide and Stable Interface Enabled by Highly Fluorinated Electrolyte[J]. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY,2021,143.
APA	Zhao, Chong.,Li, Chao.,Liu, Hui.,Qiu, Qing.,Geng, Fushan.,...&Hu, Bingwen.(2021).Coexistence of (O-2)(n-) and Trapped Molecular O-2 as the Oxidized Species in P2-Type Sodium 3d Layered Oxide and Stable Interface Enabled by Highly Fluorinated Electrolyte.JOURNAL OF THE AMERICAN CHEMICAL SOCIETY,143.
MLA	Zhao, Chong,et al."Coexistence of (O-2)(n-) and Trapped Molecular O-2 as the Oxidized Species in P2-Type Sodium 3d Layered Oxide and Stable Interface Enabled by Highly Fluorinated Electrolyte".JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 143(2021).