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Choi, Heechae ORCID: 0000-0002-9390-6607, Kim, Taeyoung and Park, Hyunjung (2022). Defect engineering of TiNb2O7 compound for enhanced Li-ion battery anode performances. Electrochim. Acta, 404. OXFORD: PERGAMON-ELSEVIER SCIENCE LTD. ISSN 1873-3859

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Abstract

Low-crystalline TiNb2O7 shows a high practical capacity of ~& nbsp;280 mAh g(-1) by size and morphology controls, composites, doping foreign atoms. However, the defect chemistry of TiNb2O7 has rarely been investigated. We report an effect of point/line defects on a crystal structure and lithium storage properties of TiNb2O7-x engineered by different calcination temperatures and vacuum conditions. X-ray diffraction studies reveal an evolution of oxygen vacancies aligned to (h over line 0l) and (0 k 0) planes can cause an increase in lattice constants and a cell volume expansion to ~& nbsp;3%. Transmission electron microscopy observation shows calcination at 800 ?& nbsp;in vacuum results in not only a size reduction of particles but also a development of edge/screw dislocations generated on ((3) over bar03 ) plane as a slip system, which can drive microstrain correlated to the lattice parameter change. TiNb2O7-x shows remarkable lithium storage properties in-cluding charge (lithiation)/discharge (delithiation) capacities of 324/284 mAh g(-1) and capacity retentions of 100% at a 2C rate over 500 cycles and at a 5C rate over 1500 cycles, respectively. The achievement is attributed to a synergetic effect of short Li+ ion path by a size reduction and reduce Li+ ion migration by an expansion of the lattice constants and the cell volume. (C) 2021 Elsevier Ltd. All rights reserved.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Choi, Heechae UNSPECIFIED orcid.org/0000-0002-9390-6607 UNSPECIFIED Kim, Taeyoung UNSPECIFIED UNSPECIFIED UNSPECIFIED Park, Hyunjung UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-666147
DOI:	10.1016/j.electacta.2021.139603
Journal or Publication Title:	Electrochim. Acta
Volume:	404
Date:	2022
Publisher:	PERGAMON-ELSEVIER SCIENCE LTD
Place of Publication:	OXFORD
ISSN:	1873-3859
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language HIGH-RATE CAPABILITY; LITHIUM; DISLOCATIONS; PRESSURE; STORAGE; OXIDES; CHARGE Multiple languages Electrochemistry Multiple languages
URI:	http://kups.ub.uni-koeln.de/id/eprint/66614