Reversible Electrochemical Interface of Mg Metal and Conventional Electrolyte Enabled by Intermediate Adsorption

Journal Article · Wed Dec 04 00:00:00 EST 2019 · ACS Energy Letters

DOI:https://doi.org/10.1021/acsenergylett.9b02211· OSTI ID:1595940

Wang, Hui  ^[1]; Feng, Xuefei ^[2]; Chen, Ying ^[3]; Liu, Yi-Sheng  ^[2]; Han, Kee Sung  ^[3]; Zhou, Mingxia  ^[4]; Engelhard, Mark H.  ^[5]; Murugesan, Vijayakumar  ^[3]; Assary, Rajeev S.  ^[4]; Liu, Tianbiao Leo ^[6]; Henderson, Wesley ^[6]; Nie, Zimin ^[6]; Gu, Meng ^[5]; Xiao, Jie  ^[6]; Wang, Chongmin  ^[5]; Persson, Kristin ^[7]; Mei, Donghai  ^[8]; Zhang, Ji-Guang  ^[6]; Mueller, Karl T.  ^[3]; Guo, Jinghua  ^[2] ; Zavadil, Kevin  ^[9]; Shao, Yuyan  ^[1]; Liu, Jun  ^[6]

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1. Energy & Environment Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, United States;Joint Center for Energy Storage Research (JCESR), Lemont Illinois 60439, United States
2. Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States;Joint Center for Energy Storage Research (JCESR), Lemont Illinois 60439, United States
3. Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, United States;Joint Center for Energy Storage Research (JCESR), Lemont Illinois 60439, United States
4. Materials Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439, United States;Joint Center for Energy Storage Research (JCESR), Lemont Illinois 60439, United States
5. Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
6. Energy & Environment Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
7. Energy Technologies Area, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States;Joint Center for Energy Storage Research (JCESR), Lemont Illinois 60439, United States;Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, California 94720, United States
8. Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
9. Material, Physical, and Chemical Sciences, Sandia National Laboratories, Albuquerque, New Mexico 87185, United States;Joint Center for Energy Storage Research (JCESR), Lemont Illinois 60439, United States

Conventional electrolytes made by mixing simple Mg2+ salts and aprotic solvents, analogous to those in Li-ion batteries, are incompatible with Mg anodes because Mg metal readily reacts with such electrolytes, producing a passivation layer that blocks Mg2+ transport. Here, we report that, through tuning a conventional electrolyte-Mg(TFSI)(2) (TEST- is N(SO2CF3)(2)(-))-with an Mg(BH4)(2) cosalt, highly reversible Mg plating/stripping with a high Coulombic efficiency is achieved by neutralizing the first solvation shell of Mg cationic clusters between Mg2+ and TFSI- and enhanced reductive stability of free MI-. A critical adsorption step between Mg-0 atoms and active Mg cation clusters involving BH4- anions is identified to be the key enabler for reversible Mg plating/stripping through analysis of the distribution of relaxation times (DRT) from operando electrochemical impedance spectroscopy (EIS), operando electrochemical Xray absorption spectroscopy (XAS), nuclear magnetic resonance (NMR), and density functional theory (DFT) calculations.

• Research Organization: Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• DOE Contract Number: AC04-94AL85000; AC05-76RL01830; AC02-06CH11357
• OSTI ID: 1595940
• Journal Information: ACS Energy Letters, Vol. 5, Issue 1; ISSN 2380-8195
• Publisher: American Chemical Society (ACS)
• Country of Publication: United States
• Language: English