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Ansari Y, Ueno K, Angell CA. Protic Ionic Liquids Can Be Both Free Proton Conductors and Benign Superacids. J Phys Chem B 2021; 125:7855-7862. [PMID: 34250812 DOI: 10.1021/acs.jpcb.1c05299] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Superacids have been the source of much spectacular chemistry but very little interesting physics despite the fact that the states of cations formed by transfer of the superacid proton to molecular bases can approach that of the cations in free space. Indeed, some of the very strongest acids, such as HPF6 and HAlCl4, have no independent existence due to lack of screening of the bare proton self-energy: their acidities can only be assessed by study of the conjugate bases. Here we show that, by allowing the protons of transient HAlCl4 and HAlBr4 to relocate on pentafluoropyridine, PFP (a very weak base that is stable to superacids), we can create glass forming protic ionic liquids (PILs) that are themselves superacids but, being free of superacid vapors, are of benign character. At Tg, conductivities exceed "good" ionic liquid values by 9 decades, so must be superprotonic. Anomalous Walden plots confirm superprotonicity.
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Affiliation(s)
- Younes Ansari
- Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287, United States.,Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Kazuhide Ueno
- Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287, United States.,Department of Chemistry and Life Science, Yokohama National University, 241-8501 Yokohama, Japan
| | - C Austen Angell
- Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287, United States
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Zhou L, Cao Z, Zhang J, Sun Q, Wu Y, Wahyudi W, Hwang JY, Wang L, Cavallo L, Sun YK, Alshareef HN, Ming J. Engineering Sodium-Ion Solvation Structure to Stabilize Sodium Anodes: Universal Strategy for Fast-Charging and Safer Sodium-Ion Batteries. NANO LETTERS 2020; 20:3247-3254. [PMID: 32319776 DOI: 10.1021/acs.nanolett.9b05355] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Sodium-ion batteries are promising alternatives for lithium-ion batteries due to their lower cost caused by global sodium availability. However, the low Coulombic efficiency (CE) of the sodium metal plating/stripping process represents a serious issue for the Na anode, which hinders achieving a higher energy density. Herein, we report that the Na+ solvation structure, particularly the type and location of the anions, plays a critical role in determining the Na anode performance. We show that the low CE results from anion-mediated corrosion, which can be tackled readily through tuning the anion interaction at the electrolyte/anode interface. Our strategy thus enables fast-charging Na-ion and Na-S batteries with a remarkable cycle life. The presented insights differ from the prevailing interpretation that the failure mechanism mostly results from sodium dendrite growth and/or solid electrolyte interphase formation. Our anionic model introduces a new guideline for improving the electrolytes for metal-ion batteries with a greater energy density.
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Affiliation(s)
- Lin Zhou
- State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, CAS, Changchun 130022, China
- University of Science and Technology of China, Hefei 230026, P. R. China
| | - Zhen Cao
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Jiao Zhang
- State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, CAS, Changchun 130022, China
- University of Science and Technology of China, Hefei 230026, P. R. China
| | - Qujiang Sun
- State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, CAS, Changchun 130022, China
| | - Yingqiang Wu
- State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, CAS, Changchun 130022, China
| | - Wandi Wahyudi
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Jang-Yeon Hwang
- Department of Energy Engineering, Hanyang University, Seoul 133-791, Republic of Korea
| | - Limin Wang
- State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, CAS, Changchun 130022, China
- University of Science and Technology of China, Hefei 230026, P. R. China
| | - Luigi Cavallo
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Yang-Kook Sun
- Department of Energy Engineering, Hanyang University, Seoul 133-791, Republic of Korea
| | - Husam N Alshareef
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Jun Ming
- State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, CAS, Changchun 130022, China
- University of Science and Technology of China, Hefei 230026, P. R. China
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