Cyano-based ionic liquids (ILs) are prime candidates for the manufacturing of cheaper and safer batteries due to their inherently low-volatility and absence of expensive fluorinated species. In this work, N-methyl-N-butylpyrrolidinium (Pyr14)-based ILs featuring two different cyano-based anions, i.e., dicyanamide (DCA) and tricyanomethanide (TCM), and their mixture with the respective Li salts (1:9 salt:IL mole ratio), alongside their combination (DCA–TCM), are evaluated as potential electrolytes for lithium metal batteries (LMBs). The electrolytes display significant ionic conductivity at room temperature (5 mS cm−1) alongside an electrochemical stability window up to 4 V, suitable for low-voltage LMBs such as Li–sulfur, as well as promising cycling stability. In addition to the detailed physicochemical (viscosity, conductivity) and electrochemical (electrochemical stability window, stripping/plating, and impedance test in symmetrical Li cells) characterization, the solid electrolyte interphase (SEI) formed in this class of ionic liquids is studied for the first time. X-ray photoelectron spectroscopy (XPS) provides evidence for an SEI dominated by a polymer-rich layer including carbon–nitrogen single, double, and triple bonds, which provides high ionic conductivity and mechanical stability, leading to the aforementioned cycling stability. Finally, a molecular insight is achieved by density functional theory (DFT) and classic molecular dynamics simulations both supporting the experimental evidence.

Nonfluorinated Ionic Liquid Electrolytes for Lithium Metal Batteries: Ionic Conduction, Electrochemistry, and Interphase Formation / Karimi, N.; Zarrabeitia, M.; Mariani, A.; Gatti, D.; Varzi, A.; Passerini, S.. - In: ADVANCED ENERGY MATERIALS. - ISSN 1614-6832. - 11:4(2021), p. 2003521. [10.1002/aenm.202003521]

Nonfluorinated Ionic Liquid Electrolytes for Lithium Metal Batteries: Ionic Conduction, Electrochemistry, and Interphase Formation

Mariani A.;
2021-01-01

Abstract

Cyano-based ionic liquids (ILs) are prime candidates for the manufacturing of cheaper and safer batteries due to their inherently low-volatility and absence of expensive fluorinated species. In this work, N-methyl-N-butylpyrrolidinium (Pyr14)-based ILs featuring two different cyano-based anions, i.e., dicyanamide (DCA) and tricyanomethanide (TCM), and their mixture with the respective Li salts (1:9 salt:IL mole ratio), alongside their combination (DCA–TCM), are evaluated as potential electrolytes for lithium metal batteries (LMBs). The electrolytes display significant ionic conductivity at room temperature (5 mS cm−1) alongside an electrochemical stability window up to 4 V, suitable for low-voltage LMBs such as Li–sulfur, as well as promising cycling stability. In addition to the detailed physicochemical (viscosity, conductivity) and electrochemical (electrochemical stability window, stripping/plating, and impedance test in symmetrical Li cells) characterization, the solid electrolyte interphase (SEI) formed in this class of ionic liquids is studied for the first time. X-ray photoelectron spectroscopy (XPS) provides evidence for an SEI dominated by a polymer-rich layer including carbon–nitrogen single, double, and triple bonds, which provides high ionic conductivity and mechanical stability, leading to the aforementioned cycling stability. Finally, a molecular insight is achieved by density functional theory (DFT) and classic molecular dynamics simulations both supporting the experimental evidence.
2021
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11566/300173
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 47
  • ???jsp.display-item.citation.isi??? 47
social impact