Analyzing the Mechanism of Functional Groups in Phosphate Additives on the Interface of LiNi0.8Co0.15Al0.05O2 Cathode Materials

doi:10.1021/acsami.0c21535

CORC > 兰州理工大学 > 兰州理工大学 > 石油化工学院

	Analyzing the Mechanism of Functional Groups in Phosphate Additives on the Interface of LiNi0.8Co0.15Al0.05O2 Cathode Materials
	Wang, Jie; Zhao, Dongni; Cong, Yuanyuan; Zhang, Ningshuang; Wang, Peng; Fu, Xiaolan; Cui, Xiaoling
刊名	ACS APPLIED MATERIALS & INTERFACES
	2021
卷号	13 期号:14 页码:16939-16951
关键词	salt-type additives cathode electrolyte interface functional group LiNi0.8Co0.15Al0.05O2 phosphorus-centered complex
ISSN号	1944-8244
DOI	10.1021/acsami.0c21535
英文摘要	The design of a functional electrolyte system that is compatible with the LiNi0.8Co0.15Al0.05O2 (LNCA) cathode is of great importance for advanced lithium-ion batteries (LIBs). In this work, chelated lithium salts of lithium difluoro(bisoxalato) phosphate (LiDFBOP) and lithium tetrafluoro(oxalate) phosphate (LTFOP) are synthesized by a facile and general method. Then, the complexes of LiDFBOP, LTFOP, and lithium difluorophosphate (LiDFP), all of which have a central phosphorus atom, were selected as the salt-type additives for the LiPF6-based electrolyte to improve the electrochemical performances of LNCA/Li half-batteries, respectively. The results of electrochemical tests, quantum chemistry calculations, potential-resolved in situ electrochemical impedance (PRIs-EIS) measurements, and surface analyses show that the interface property and the battery performance are closely associated with molecular structures of phosphorus-centered complex additives. It indicates that LiDFP with the P=O bond can significantly reduce the interfacial impedance of LNCA/Li half-batteries due to the increase of Li3PO4 and the decrease of Li2CO3 in the cathode electrolyte interface (CEI). While in LiDFBOP, according to the calculated vertical ionization potential (VIP), the two oxalate-chelated ligands bring about a bidirectional cross-linking reaction, which makes it preferential to be oxidized. This process is self-healing and can form a dense and stretched CEI, which is favorable to the cycle performance at the late stage. In contrast, the polymerization reaction will occur in one direction for LTFOP due to its lone oxalate ligand. Additionally, an unfavorable side reaction between LTFOP and EC has been proposed by the aid of Gibbs free energy calculation. This is a good explanation for the formation of the uneven and unstable CEI, as well as the continuous decomposition of the electrolyte in PRIs-EIS measurement. This work has an extensive applicability and practical significance not only for molecular designing of novel lithium salts, but also for the construction of a functional electrolyte system that is compatible with different electrode materials.
WOS研究方向	Science & Technology - Other Topics ; Materials Science
语种	英语
出版者	AMER CHEMICAL SOC
WOS记录号	WOS:000641156600096
内容类型	期刊论文
源URL	[http://ir.lut.edu.cn/handle/2XXMBERH/148259]
专题	石油化工学院
作者单位	Lanzhou Univ Technol, Coll Petrochem Technol, Lanzhou 730050, Peoples R China
推荐引用方式 GB/T 7714	Wang, Jie,Zhao, Dongni,Cong, Yuanyuan,et al. Analyzing the Mechanism of Functional Groups in Phosphate Additives on the Interface of LiNi0.8Co0.15Al0.05O2 Cathode Materials[J]. ACS APPLIED MATERIALS & INTERFACES,2021,13(14):16939-16951.
APA	Wang, Jie.,Zhao, Dongni.,Cong, Yuanyuan.,Zhang, Ningshuang.,Wang, Peng.,...&Cui, Xiaoling.(2021).Analyzing the Mechanism of Functional Groups in Phosphate Additives on the Interface of LiNi0.8Co0.15Al0.05O2 Cathode Materials.ACS APPLIED MATERIALS & INTERFACES,13(14),16939-16951.
MLA	Wang, Jie,et al."Analyzing the Mechanism of Functional Groups in Phosphate Additives on the Interface of LiNi0.8Co0.15Al0.05O2 Cathode Materials".ACS APPLIED MATERIALS & INTERFACES 13.14(2021):16939-16951.