Effect of Salt Concentration on the Interfacial Solvation Structure and Early Stage of Solid–Electrolyte Interphase Formation in Ca(BH4)2/THF for Ca Batteries
[1];
[1];
[1];
- Argonne National Laboratory (ANL), Argonne, IL (United States). Chemical Sciences and Engineering Division; Argonne National Laboratory (ANL), Argonne, IL (United States). Joint Center for Energy Storage Research (JCESR)
- Argonne National Laboratory (ANL), Argonne, IL (United States). Joint Center for Energy Storage Research (JCESR)
The Ca2+ solvation structure at the electrolyte/electrode interface is of central importance to understand electroreduction stability and solid–electrolyte interphase (SEI) formation for the novel multivalent Ca battery systems. Here, using an exemplar electrolyte, the concentration-dependent solvation structure of Ca(BH4)2-tetrahydrofuran on a gold model electrode has been investigated with various electrolyte concentrations via electrochemical quartz crystal microbalance with dissipation (EQCM-D) and X-ray photoelectron spectroscopy (XPS). For the first time, in situ EQCM-D results prove that the prevalent species adsorbed at the interface is CaBH4+ across all concentrations. As the salt concentration increases, the number of BH4– anions associated with Ca2+ increases, and much larger solvated complexes such as CaBH4+·4THF or Ca(BH4)3–·4THF form at the interface at high concentrations prior to Ca plating. Different interfacial chemistries lead to the formation of SEIs with different components demonstrated by XPS. High electrolyte concentrations reduce the solvent decomposition and promote the formation of thick, uniform, and inorganic-rich (i.e., CaO) SEI layers, which contribute to improved Ca plating efficiency and current density in electrochemical measurements.
- Research Organization:
- Argonne National Laboratory (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- Grant/Contract Number:
- AC02-06CH11357
- OSTI ID:
- 1989124
- Journal Information:
- ACS Applied Materials and Interfaces, Vol. 15, Issue 20; ISSN 1944-8244
- Publisher:
- American Chemical Society (ACS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Similar Records
The critical role of configurational flexibility in facilitating reversible reactive metal deposition from borohydride solutions
Investigation of Solid Electrolyte Interphase Layer Formation and Electrochemical Reversibility of Magnetite, Fe 3 O 4 , Electrodes: A Combined X-ray Absorption Spectroscopy and X-ray Photoelectron Spectroscopy Study