Passivation dynamics in the anisotropic deposition and stripping of bulk magnesium electrodes during electrochemical cycling

Journal Article · Mon Aug 10 00:00:00 EDT 2015 · ACS Applied Materials and Interfaces

DOI:https://doi.org/10.1021/acsami.5b04487· OSTI ID:1235306

Wetzel, David J. ^[1]; Malone, Marvin A. ^[1]; Haasch, Richard T. ^[1]; Meng, Yifei ^[1]; Vieker, Henning ^[2]; Hahn, Nathan ^[3]; Golzhauser, Armin ^[2]; Zuo, Jian-Min ^[1]; Zavadil, Kevin R. ^[3]; Gewirth, Andrew A. ^[1]; Nuzzo, Ralph G. ^[1]

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1. Univ. of Illinois, Urbana, IL (United States)
2. Univ. of Bielefeld, Bielefeld (Germany)
3. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

Rechargeable magnesium (Mg) batteries show promise for use as a next generation technology for high-density energy storage, though little is known about the Mg anode solid electrolyte interphase and its implications for the performance and durability of a Mg-based battery. We explore in this report passivation effects engendered during the electrochemical cycling of a bulk Mg anode, characterizing their influences during metal deposition and dissolution in a simple, nonaqueous, Grignard electrolyte solution (ethylmagnesium bromide, EtMgBr, in tetrahydrofuran). Scanning electron microscopy images of Mg foil working electrodes after electrochemical polarization to dissolution potentials show the formation of corrosion pits. The pit densities so evidenced are markedly potential-dependent. When the Mg working electrode is cycled both potentiostatically and galvanostatically in EtMgBr these pits, formed due to passive layer breakdown, act as the foci for subsequent electrochemical activity. Detailed microscopy, diffraction, and spectroscopic data show that further passivation and corrosion results in the anisotropic stripping of the Mg {0001} plane, leaving thin oxide-comprising passivated side wall structures that demark the {0001} fiber texture of the etched Mg grains. Upon long-term cycling, oxide side walls formed due to the pronounced crystallographic anisotropy of the anodic stripping processes, leading to complex overlay anisotropic, columnar structures, exceeding 50 μm in height. Finally, the passive responses mediating the growth of these structures appear to be an intrinsic feature of the electrochemical growth and dissolution of Mg using this electrolyte.

• Research Organization: Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• Grant/Contract Number: AC04-94AL85000
• OSTI ID: 1235306
• Report Number(s): SAND-2015-4340J; 590456
• Journal Information: ACS Applied Materials and Interfaces, Vol. 7, Issue 33; ISSN 1944-8244
• Publisher: American Chemical Society
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
36 MATERIALS SCIENCE
rechargeable magnesium battery
magnesium anode
passivation
corrosion
columnar growth