Artificial SEI layers for sodium-ion battery through ALD/MLD
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Journal Title
Journal ISSN
Volume Title
Kemian tekniikan korkeakoulu |
Master's thesis
Authors
Date
2022-08-23
Department
Major/Subject
Funtional Materials for Global Challenges
Mcode
CHEM3061
Degree programme
Master's Programme in Advanced Materials for Innovation and Sustainability
Language
en
Pages
72+10
Series
Abstract
Sodium-ion batteries suffer from dendrite growth, resulting in safety issues and a short cycle life. A stable solid electrolyte interphase (SEI) layer could solve these problems. The literature part of this thesis presents the variety of different methods and materials investigated for artificial SEI layers. It is demonstrated that the atomic/molecular layer deposition (ALD/MLD) technique is particularly promising for the deposition of defect-free artificial SEI layers due to its atomically precise layer thickness and composition control. Based on the materials considered, it appears that Li-EG (EG: ethylene glycol) is an interesting candidate material for protecting the lithium anode. This hybrid film deposited through ALD/MLD provided the framework for the experimental part of this thesis. The experiments proved that it was straightforward to reproduce the Li-EG and Li-EG-CO films. Additionally, the preparation of novel sodium hybrid films via ALD/MLD was successful, and the process parameters could be optimized towards growth rates up to 3 Å/C. A film transformation into crystalline Na2CO3 and Na3H(CO2)3 in a humid environment was detected. The attempt to convert the Na-EG films into sodium ethylene carbonate films was not successful. The results of this work are expected to provide a promising starting point for the deposition of hybrid sodium-organic coatings for next generation sodium-ion battery applications.Description
Supervisor
Karppinen, MaaritThesis advisor
Madadi, MiladHeiska, Juho
Keywords
ALD/MLD, artificial SEI, sodium-ion battery, alkali metal thin film, hybrid materials