Interfacial Chemistry Effects in the Electrochemical Performance of Silicon Electrodes under Lithium-Ion Battery Conditions

Understanding the solid electrolyte interphase (SEI) formation and (de)lithiation phenomena at silicon (Si) electrodes is key to improving the performance and lifetime of Si-based lithium-ion batteries. However, these processes remain somewhat elusive, and, in particular, the role of Si surface term...

Full description

Saved in:
Bibliographic Details
Published in:Small (Weinheim an der Bergstrasse, Germany) Germany), 2023-10, Vol.19 (40), p.e2303442
Main Authors: Xu, Xiangdong, Martín-Yerga, Daniel, Grant, Nicholas E, West, Geoff, Pain, Sophie L, Kang, Minkyung, Walker, Marc, Murphy, John D, Unwin, Patrick R
Format: Article
Language:English
Subjects:
Combinatorial analysis
Cycles
Electrochemical analysis
Electrochemical cells
Electrodes
Glove boxes
Heterogeneity
Hydrofluoric acid
Ions
Lithium
Lithium-ion batteries
Nanotechnology
Secondary ion mass spectrometry
Silicon
Solid electrolytes
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Understanding the solid electrolyte interphase (SEI) formation and (de)lithiation phenomena at silicon (Si) electrodes is key to improving the performance and lifetime of Si-based lithium-ion batteries. However, these processes remain somewhat elusive, and, in particular, the role of Si surface termination merits further consideration. Here, scanning electrochemical cell microscopy (SECCM) is used in a glovebox, followed by secondary ion mass spectrometry (SIMS) at identical locations to study the local electrochemical behavior and associated SEI formation, comparing Si (100) with a native oxide layer (SiO /Si) and etched with hydrofluoric acid (HF-Si). HF-Si shows greater spatial electrochemical heterogeneity and inferior lithiation reversibility than SiO /Si. This is attributed to a weakly passivating SEI and irreversible lithium trapping at the Si surface. Combinatorial screening of charge/discharge cycling by SECCM with co-located SIMS reveals SEI chemistry as a function of depth. While the SEI thickness is relatively independent of the cycle number, the chemistry - particularly in the intermediate layers - depends on the number of cycles, revealing the SEI to be dynamic during cycling. This work serves as a foundation for the use of correlative SECCM/SIMS as a powerful approach to gain fundamental insights on complex battery processes at the nano- and microscales.
ISSN:1613-6810
1613-6829
DOI:10.1002/smll.202303442