Electrochemistry is necessarily a science of interfacial processes, and understanding electrode/electrolyte interfaces is essential to controlling electrochemical performance and stability. Undesirable interfacial interactions hinder discovery and development of rational materials combinations. By example, we examine an electrolyte, magnesium(II) bis(trifluoromethanesulfonyl)imide (Mg(TFSI)2) dissolved in diglyme, next to the Mg metal anode, which is purported to have a wide window of electrochemical stability. However, even in the absence of any bias, using in situ tender X-ray photoelectron spectroscopy, we discovered an intrinsic interfacial chemical instability of both the solvent and salt, further explained using first-principles calculations as driven by Mg2+ dication chelation and nucleophilic attack by hydroxide ions. The proposed mechanism appears general to the chemistry near or on metal surfaces in hygroscopic environments with chelation of hard cations and indicates possible synthetic strategies to overcome chemical instability within this class of electrolytes.
Yu, Yi, et al. "Instability at the Electrode/Electrolyte Interface Induced by Hard Cation Chelation and Nucleophilic Attack." Chemistry of Materials, vol. 29, no. 19, Sep. 2017. https://doi.org/10.1021/acs.chemmater.7b03404
Yu, Yi, Baskin, Artem, Valero-Vidal, Carlos, Hahn, Nathan T., Liu, Qiang, Zavadil, Kevin R., Eichhorn, Bryan W., Prendergast, David, & Crumlin, Ethan J. (2017). Instability at the Electrode/Electrolyte Interface Induced by Hard Cation Chelation and Nucleophilic Attack. Chemistry of Materials, 29(19). https://doi.org/10.1021/acs.chemmater.7b03404
Yu, Yi, Baskin, Artem, Valero-Vidal, Carlos, et al., "Instability at the Electrode/Electrolyte Interface Induced by Hard Cation Chelation and Nucleophilic Attack," Chemistry of Materials 29, no. 19 (2017), https://doi.org/10.1021/acs.chemmater.7b03404
@article{osti_1473937,
author = {Yu, Yi and Baskin, Artem and Valero-Vidal, Carlos and Hahn, Nathan T. and Liu, Qiang and Zavadil, Kevin R. and Eichhorn, Bryan W. and Prendergast, David and Crumlin, Ethan J.},
title = {Instability at the Electrode/Electrolyte Interface Induced by Hard Cation Chelation and Nucleophilic Attack},
annote = {Electrochemistry is necessarily a science of interfacial processes, and understanding electrode/electrolyte interfaces is essential to controlling electrochemical performance and stability. Undesirable interfacial interactions hinder discovery and development of rational materials combinations. By example, we examine an electrolyte, magnesium(II) bis(trifluoromethanesulfonyl)imide (Mg(TFSI)2) dissolved in diglyme, next to the Mg metal anode, which is purported to have a wide window of electrochemical stability. However, even in the absence of any bias, using in situ tender X-ray photoelectron spectroscopy, we discovered an intrinsic interfacial chemical instability of both the solvent and salt, further explained using first-principles calculations as driven by Mg2+ dication chelation and nucleophilic attack by hydroxide ions. The proposed mechanism appears general to the chemistry near or on metal surfaces in hygroscopic environments with chelation of hard cations and indicates possible synthetic strategies to overcome chemical instability within this class of electrolytes.},
doi = {10.1021/acs.chemmater.7b03404},
url = {https://www.osti.gov/biblio/1473937},
journal = {Chemistry of Materials},
issn = {ISSN 0897-4756},
number = {19},
volume = {29},
place = {United States},
publisher = {American Chemical Society (ACS)},
year = {2017},
month = {09}}
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Energy Frontier Research Centers (EFRC) (United States). Nanostructures for Electrical Energy Storage (NEES)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Grant/Contract Number:
AC04-94AL85000
OSTI ID:
1473937
Alternate ID(s):
OSTI ID: 1480074
Report Number(s):
SAND--2018-9890J; 667716
Journal Information:
Chemistry of Materials, Journal Name: Chemistry of Materials Journal Issue: 19 Vol. 29; ISSN 0897-4756