Abstract
Silicon oxides (SiOx) have been considered as promising alternatives to pure Si in high energy anodes in lithium-ion batteries (LIBs) due to their improved cycling stability. However, their fundamental lithiation mechanism has not yet been systematically investigated, and potential collateral downsides remain unclear. In this work, we report on the role of oxygen in lithiation/delithiation and solid electrolyte interphase (SEI) formation processes in SiOx thin film model electrodes with different oxygen contents. We show that the SiOx anodes with higher oxygen content experience smaller volume change and form a thinner and more stable SEI, both of which are beneficial for cycling stability. However, these SiOx anodes also show an irreversible lithiation at around 0.7 V attributed to the reduction of Si oxides, leading to lower first cycle coulombic efficiency that is undesirable for practical applications. Overall, these results offer a balanced perspective on the advantages and disadvantages that oxygen brings to Si-based anodes in LIBs.
Original language | American English |
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Article number | 120512 |
Number of pages | 6 |
Journal | Journal of the Electrochemical Society |
Volume | 169 |
Issue number | 12 |
DOIs | |
State | Published - 2022 |
Bibliographical note
Publisher Copyright:© 2022 The Electrochemical Society (“ECS”). Published on behalf of ECS by IOP Publishing Limited.
NREL Publication Number
- NREL/JA-5K00-84414
Keywords
- Li-ion batteries
- lithiation process
- SEI formation
- Si thin film electrode
- silicon oxides anodes