Raman spectroscopy,

authors	Pelegov, DV; Slautin, BN; Gorshkov, VS; Zelenovskiy, PS; Kiselev, EA; Kholkin, AL; Shur, VY
nationality	International
journal	JOURNAL OF POWER SOURCES
author keywords	Oxygen vacancies; Lithium vacancies; Negative electrode material; Li4Ti5O12; Nonstoichiometry; Automated experiment
keywords	LI-ION BATTERIES; ELECTROCHEMICAL PROPERTIES; NEGATIVE ELECTRODE; OXYGEN VACANCIES; SPINEL LI4TI5O12; TITANIUM-SPINEL; RATE-CAPABILITY; CYCLE LIFE; PERFORMANCE; ANODE
abstract	Existence of defects is an inherent property of real materials. Due to an explicit correlation between defects concentration and conductivity, it is important to understand the level and origins of the structural heterogeneity for any particulate electrode material. Poor conductive lithium titanate Li4Ti5O12 (LTO), widely used in batteries for grids and electric buses, needs it like no one else. In this work, structural heterogeneity of compacted lithium titanate is measured locally in 100 different points by conventional micro-Raman technique, characterized in terms of variation of Raman spectra parameters and interpreted using our version of "big data" analysis. This very simple approach with automated measurement and treatment has allowed us to demonstrate inherent heterogeneity of solid-state synthesized LTO and attribute it to the existence of lithium and oxygen vacancies. The proposed approach can be used as a fast, convenient, and cost-effective defects-probing tool for a wide range of materials with defects-sensitive properties. In case of LTO, such an approach can be used to increase its charge/discharge rates by synthesis of materials with controlled nonstoichiometry. New approaches to solid state synthesis of LTO, suitable for high-power applications, will help to significantly reduce the costs of batteries for heavy-duty electric vehicles and smart-grids. (C) 2017 Elsevier B.V. All rights reserved.
publisher	ELSEVIER SCIENCE BV
issn	0378-7753
isbn	1873-2755
year published	2017
volume	346
beginning page	143
ending page	150
digital object identifier (doi)	10.1016/j.jpowsour.2017.02.024
web of science category	Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary
subject category	Chemistry; Electrochemistry; Energy & Fuels; Materials Science
unique article identifier	WOS:000398008900018