Title: Current Density Regulated Atomic to Nanoscale Process on Li Deposition and Solid Electrolyte Interphase Revealed by Cryogenic Transmission Electron Microscopy

Abstract

Current density has been perceived to play a critical rule for controlling Li deposition morphology and solid electrolyte interphase (SEI). However, the atomic level mechanism of current density on Li deposition and the SEI remains unclear. In this work, based on cryogenic transmission electron microscopy imaging combined with energy dispersive X-ray spectroscopy and electron energy loss spectroscopy electronic structure analyses, we reveal the atomic level correlation of Li deposition morphology and SEI with current density. We discover that increasing current density leads to increased overpotential for Li nucleation and growth, leading to the transition from growth-limited to nucleation-limited mode for Li dendrite. Independence of current density, the electrochemically deposited Li metal (EDLi) exhibits crystalline whisker-like morphology. The SEI formed at low current density (0.1 mA cm^-2) is monolithic amorphous; while, a current density of above 2 mA cm^-2 leads to a mosaic structured SEI, featuring an amorphous matrix with Li₂O and LiF dispersoids, and the thickness of the SEI increases with the increase of current density. Uniquely, the Li₂O particles is spatially located at the top surface of the SEI, while LiF is spatially adjacent to the Li-SEI interface. These results highlight the possible tuning of crucial structural and chemicalmore » features of EDLi and SEI through altering deposit conditions and consequently direct correlation with electrochemical performance.« less

Authors:

Xu, Yaobin  ^[1];

• Search DOE PAGES for author "Xu, Yaobin"
• Search DOE PAGES for ORCID "0000-0002-9945-3514"

Wu, Haiping  ^[2];

• Search DOE PAGES for author "Wu, Haiping"
• Search DOE PAGES for ORCID "0000-0003-1904-652X"

Jia, Hao  ^[2];

• Search DOE PAGES for author "Jia, Hao"
• Search DOE PAGES for ORCID "0000-0003-2814-5589"

Zhang, Ji-Guang  ^[2];

• Search DOE PAGES for author "Zhang, Ji-Guang"
• Search DOE PAGES for ORCID "0000-0001-7343-4609"

Xu, Wu  ^[2];

• Search DOE PAGES for author "Xu, Wu"
• Search DOE PAGES for ORCID "0000-0002-2685-8684"

Wang, Chongmin  ^[1]

• Search DOE PAGES for author "Wang, Chongmin"
• Search DOE PAGES for ORCID "0000-0003-3327-0958"

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+ Show Author Affiliations

1. Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL)
2. Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

Publication Date:

Mon Jun 29 00:00:00 EDT 2020

Research Org.:

Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

Sponsoring Org.:

USDOE Office of Energy Efficiency and Renewable Energy (EERE); USDOE Office of Science (SC), Biological and Environmental Research (BER)

OSTI Identifier:

1668332

Report Number(s):

PNNL-SA-152803
Journal ID: ISSN 1936-0851

Grant/Contract Number:  

AC05-76RL01830; LC000L072

Resource Type:

Accepted Manuscript

Journal Name:

ACS Nano

Additional Journal Information:

Journal Volume: 14; Journal Issue: 7; Journal ID: ISSN 1936-0851

Publisher:

American Chemical Society (ACS)

Country of Publication:

United States

Language:

English

Subject:

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Lithium metal, cryo-TEM, electrochemical deposition, solid electrolyte interphase, current density