Structure and surface chemistry of Al2O3 coated LiMn2O4 nanostructured electrodes with improved lifetime

标题

Structure and surface chemistry of Al2O3 coated LiMn2O4 nanostructured electrodes with improved lifetime

作者

作者:Waller, GH (Waller, G. H.)^[1 ]; Brooke, PD (Brooke, P. D.)^[1 ]; Rainwater, BH (Rainwater, B. H.)^[1 ]; Lai, SY (Lai, S. Y.)^[1 ]; Hu, R (Hu, R.)^[1,2 ]; Ding, Y (Ding, Y.)^[1 ]; Alamgir, FM (Alamgir, F. M.)^[1 ]; Sandhage, KH (Sandhage, K. H.)^[1,3 ]; Liu, ML (Liu, M. L.)^[1 ]

期刊信息

摘要

Aluminum oxide coatings deposited on LiMn2O4/carbon fiber electrodes by atomic layer deposition (ALD) are shown to enhance cathode performance in lithium-ion batteries. With a thin Al2O3 coating derived from 10 ALD cycles, the electrodes exhibit 2.5 times greater capacity retention over 500 cycles at a rate of 1C as well as enhanced rate capability and decreased polarization resistance. Structural and surface studies of the electrodes before and after cycling reveal that a near-surface phenomenon is responsible for the improved electrochemical performance. The crystal structure and overall morphology of the LiMn2O4 electrode are found to be unaffected by electrochemical cycling, both for coated and uncoated samples. However, evidence of Mn diffusion into the ALD coatings is observed from both transmission electron microscopy/energy-dispersive X-ray spectroscopy (TEM-EDS) and X-ray Photoelectron Spectroscopy (XPS) after electrochemical cycling. Furthermore, XPS analysis of the Al 2p photoemission peak for the ALD coated electrodes reveal a significant shift in binding energy and peak shape, suggesting the presence of an Al-O-F compound formed by sequestering HF in the electrolyte. These observations provide new insight toward understanding the mechanism in which ultrathin coatings of amphoteric oxides can inhibit capacity loss for LiMn2O4 cathodes in lithium-ion batteries. (C) 2015 Elsevier B.V. All rights reserved.

关键词

作者关键词:LiMn2O4 cathode; Atomic layer deposition of Al2O3; X-ray photoelectron spectroscopy; Lithium-ion battery

作者信息

作者信息

通讯作者地址:Liu, ML (通讯作者)

Georgia Inst Technol, Sch Mat Sci & Engn, 771 Ferst Dr, Atlanta, GA 30332 USA.   增强组织信息的名称     Georgia Institute of Technology     University System of Georgia

地址:

	[ 1 ] Georgia Inst Technol, Sch Mat Sci & Engn, 771 Ferst Dr, Atlanta, GA 30332 USA   增强组织信息的名称     Georgia Institute of Technology     University System of Georgia
	[ 2 ] S China Univ Technol, Guangdong Prov Key Lab Adv Energy Storage Mat, Sch Mat Sci & Engn, 381 Wushan Rd, Guangzhou 510640, Peoples R China   增强组织信息的名称     South China University of Technology
	[ 3 ] Purdue Univ, Sch Mat Engn, 701 W Stadium Ave, W Lafayette, IN 47907 USA   增强组织信息的名称     Purdue University System     Purdue University

电子邮件地址:meilin.liu@mse.gatech.edu

出版商

ELSEVIER SCIENCE BV, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS

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