Abstract
The active role of alumina, pentalithium aluminate (Li5AlO4, Li-aluminate), and pentasodium aluminate (Na5AlO4, Na-aluminate) as the surface protection coatings produced via atomic layer deposition on Li and Mn-rich NCM cathode materials 0.33Li2MnO3·0.67LiNi0.4Co0.2Mn0.4O2 is discussed. A notable improvement in the electrochemical behavior of the coated cathodes has been found while tested in Li-coin cells at 30 °C. Though all the coated cathodes demonstrate enhanced electrochemical cycling and rate performances, Na-aluminate coated cathodes exhibit exemplary behavior. Prolonged cycling and rate capability testing demonstrate that after more than 400 cycles at 1 C rate, the uncoated cathode delivers only 63 mAh g−1, while those with alumina, Li-aluminate, and Na-aluminate coatings exhibit approximately two times higher specific capacities. The coated cathodes display steady average discharge potential and lower evolution of the voltage hysteresis during prolonged cycling compared to the uncoated cathode. Importantly, Na-aluminate coated cathode shows a lowering in gases (O2, CO2, H2, etc.) evolution. Post-cycling analysis of the electrodes demonstrates higher morphological integrity of the coated cathode materials and lower transition metals dissolution from them. The coatings mitigate undesirable side reactions between the electrodes and the electrolyte solution in the cells.
Original language | English |
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Article number | 2008083 |
Journal | Advanced Functional Materials |
Volume | 31 |
Issue number | 8 |
DOIs | |
State | Published - 17 Feb 2021 |
Bibliographical note
Publisher Copyright:© 2020 Wiley-VCH GmbH
Funding
S.M. and H.S. contributed equally to this work. A part of the work presented here was funded by BASF, Germany, by the Israeli Prime Minister's Office, and the Israeli Committee for High Education within the framework of the INREP project.
Funders | Funder number |
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Israeli Committee for High Education | |
Israeli Prime Minister's Office | |
BASF |
Keywords
- Li and Mn-rich NCM cathode materials
- Li-ion batteries
- atomic layer deposition
- high energy NCM
- protecting interphases