Abstract
The formation and growth of the Li2O2 discharge product impacts the reversibility of the oxygen evolution and reduction reactions in Li-O2 batteries which may lead to a shorter cycle life. A clear understanding of the surface reactions and the growth mechanism of Li2O2 requires probing dynamic changes on the surface of the positive electrodes in situ during the discharge of a Li-O2 battery. To investigate this, we establish an experimental system by adopting a multi-beam optical sensor (MOS) and developing a custom-made battery cell. First, the accuracy and reliability of the system was demonstrated by analyzing the stress accumulation on the Au negative electrode during Li plating/stripping, and the results were consistent with an earlier single-beam scanning deflectometry report. Then, the Li-O2 battery was discharged in LiNO3 in diglyme electrolyte by applying either linear sweep voltammetry or by applying constant current under an O2 environment. Control experiments in Argon-saturated electrolytes indicate surface stress generation due to charge-induced stress. The stress generation on Au positive electrode is attributed to the formation of Li2O2 reaction products on the Au surface and charge-induced stress.
Original language | English |
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Article number | 110551 |
Journal | Journal of the Electrochemical Society |
Volume | 168 |
Issue number | 11 |
DOIs | |
State | Published - Nov 2021 |
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Materials Chemistry
- Surfaces, Coatings and Films
- Electrochemistry
- Renewable Energy, Sustainability and the Environment