Journal
ADVANCED MATERIALS INTERFACES
Volume 9, Issue 25, Pages -Publisher
WILEY
DOI: 10.1002/admi.202200733
Keywords
cathodes; high-voltage spinel; Li-ion micro-battery; LiNi0.5Mn1.5O4 thin film; Raman spectroscopy
Funding
- French ANR within the CASSIOPES project [ANR-17-CE09-0016-01]
- French network on electrochemical energy storage (RS2E)
- Store-Ex Labex
- Chevreul Institute (FR 2638)
- Ministere de l'Enseignement Superieur et de la Recherche
- Region Hauts de France
- FEDER
- Agence Nationale de la Recherche (ANR) [ANR-17-CE09-0016] Funding Source: Agence Nationale de la Recherche (ANR)
Ask authors/readers for more resources
This study investigates the Li extraction-insertion mechanism in sputtered LNMO thin films using X-ray diffraction and Raman spectroscopy. The results reveal a one-step phase transition involving two cubic phases. Significant variations in the Raman spectra linked to the activity of the Ni redox system at 4.7 V were observed.
Due to its great theoretical capacity (147 mAh g(-1)) and high operating potential (4.7 V vs Li+/Li), Co-free spinel LiNi0.5Mn1.5O4 (LNMO) is one of the most promising thin film cathodes allowing designing Li-ion micro-batteries with a high specific energy. In this work, the Li extraction-insertion mechanism in sputtered LNMO thin films is investigated by X-ray diffraction and Raman spectroscopy during the first electrochemical cycle. A one-step phase transition involving two cubic phases is revealed, consisting of a wide solid solution region (0.3 <= x <= 1 in LixNMO) and a narrow biphasic domain (0 < x <= 0.3). Remarkably, significant variations are observed in the Raman spectra, which are linked to the activity of the Ni redox system at 4.7 V. It is demonstrated that an appropriate analysis of the bands corresponding to pure Ni-O stretching modes leads to an accurate estimation of the electrode states of charge and depth of discharge, which opens the way for a reliable quantification of the self-discharge phenomenon. The mechanism of Li extraction insertion here pictured for the first time for LNMO thin layers is consistent with their disordered nature and accounts for their good electrochemical performance.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available