Na insertion into nanocrystalline Li4Ti5O12 spinel: An electrochemical study

0475663 - ÚFCH JH 2018 RIV GB eng J - Journal Article
Zukalová, Markéta - Pitňa Lásková, Barbora - Klementová, Mariana - Kavan, Ladislav
Na insertion into nanocrystalline Li4Ti5O12 spinel: An electrochemical study.
Electrochimica acta. Roč. 245, AUG 2017 (2017), s. 505-511. ISSN 0013-4686. E-ISSN 1873-3859
R&D Projects: GA ČR GA15-06511S; GA MŠMT LM2015087
Institutional support: RVO:61388955 ; RVO:68378271
Keywords : Na insertion * Li4Ti5O12 * nanocrystalline
OECD category: Electrochemistry (dry cells, batteries, fuel cells, corrosion metals, electrolysis); Condensed matter physics (including formerly solid state physics, supercond.) (FZU-D)
Impact factor: 5.116, year: 2017

Na insertion into sol-gel made nanocrystalline spinel, Li4Ti5O12 (nano LTS) and reference commercial spinel (Aldrich LTS) is studied by cyclic voltammetry and galvanostatic chronopotentiometry at 1C and 2C charging/discharging rates. Nanocrystalline LTS exhibits the best performance for Na storage, its charge capacities reach 156 mAhg-1 and are twice as high as those of reference Aldrich LTS. A capacity drop of nano LTS taking place during galvanostatic cycling is ascribed to irreversible structural changes induced by Na accommodation in the Li4Ti5O12 lattice. Raman spectroscopy of nano LTS after Na insertion reveals a formation of orthorhombic Li0,5TiO2 phase in original nanocrystalline Li4Ti5O12. The occurrence of this phase, which is commonly formed during Li insertion into anatase, is discussed in terms of induced Li redistribution and its accommodation in very minor anatase impurities detectable by Raman spectroelectrochemistry and HRTEM, but visible neither by X-ray diffractometry nor cyclic voltammetry of Na insertion.
Permanent Link: http://hdl.handle.net/11104/0272320