TY  - JOUR
AU  - Sun, Ruoheng
AU  - Jakes, Peter
AU  - Eurich, Svitlana
AU  - van Holt, Désirée
AU  - Yang, Shuo
AU  - Homberger, Melanie
AU  - Simon, Ulrich
AU  - Kungl, Hans
AU  - Eichel, Rüdiger-A.
TI  - Secondary-Phase Formation in Spinel-type LiMn2O4-Cathode Materials for Lithium-Ion Batteries – Quantifying Trace Amounts of Li2MnO3 by Electron Paramagnetic Resonance Spectroscopy
JO  - Applied magnetic resonance
VL  - 49
IS  - 4
SN  - 0937-9347
CY  - Wien [u.a.]
PB  - Springer
M1  - FZJ-2018-01688
SP  - 415-427
PY  - 2018
AB  - Spinel-type lithium manganese oxides are considered as promising cathode materials for lithium-ion batteries. Trace amounts of Li2MnO3 usually occur as a secondary phase in lithium-manganese spinels in the common high-temperature, solid-state synthesis, affecting the overall Li–Mn stoichiometry in the spinel phase and thereby the electrochemical performance. However, the formation of Li2MnO3 lower than 1 wt.% can hardly be quantified by the conventional analytical techniques. In this work, we synthesized lithium-manganese spinels with different Li/Mn molar ratios and demonstrate that electron paramagnetic resonance (EPR) enables quantifying trace amounts of Li2MnO3 below 10−2 wt.% in the synthesized products. The results reveal that the formation of Li2MnO3 secondary phase is favored by lithium excess in the synthesis. Based on the quantitative evaluation of the EPR data, precise determining Li–Mn stoichiometry in the spinel phase in Li1+xMn2−xO4 materials can be assessed. Accordingly, it is possible to estimate the amount of lithium on 16d-sites in the Li-rich manganese spinels.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000427474000009
DO  - DOI:10.1007/s00723-018-0983-4
UR  - https://juser.fz-juelich.de/record/844247
ER  -