The Role of Ionic Liquid in Oxygen Reduction Reaction for Lithium-air Batteries (original) (raw)
Related papers
Electrochimica Acta, 2012
The oxygen redox reaction (ORR) in pyrrolidinium-based ionic liquids (ILs) without and with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) is investigated at different temperatures for lithium/oxygen battery application. Results obtained by cyclic voltammetry, rotating disk electrode, and ultramicroelectrode potential steps at glassy carbon are reported and discussed in relation to the physical-chemical properties of the investigated ILs. Diffusion coefficients and solubility of oxygen in the ILs and tentative values of ORR heterogeneous rate constant in ILs without LiTFSI are reported. The effect of lithium salt on the ORR in IL is also discussed in view of lithium/oxygen battery application.
An advanced lithium-air battery exploiting an ionic liquid-based electrolyte
Nano letters, 2014
A novel lithium-oxygen battery exploiting PYR14TFSI-LiTFSI as ionic liquid-based electrolyte medium is reported. The Li/PYR14TFSI-LiTFSI/O2 battery was fully characterized by electrochemical impedance spectroscopy, capacity-limited cycling, field emission scanning electron microscopy, high-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy. The results of this extensive study demonstrate that this new Li/O2 cell is characterized by a stable electrode-electrolyte interface and a highly reversible charge-discharge cycling behavior. Most remarkably, the charge process (oxygen oxidation reaction) is characterized by a very low overvoltage, enhancing the energy efficiency to 82%, thus, addressing one of the most critical issues preventing the practical application of lithium-oxygen batteries.
Ionic liquid electrolytes for Li-air batteries: lithium metal cycling
International journal of molecular sciences, 2014
In this work, the electrochemical stability and lithium plating/stripping performance of N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (Pyr14TFSI) are reported, by investigating the behavior of Li metal electrodes in symmetrical Li/electrolyte/Li cells. Electrochemical impedance spectroscopy measurements and galvanostatic cycling at different temperatures are performed to analyze the influence of temperature on the stabilization of the solid electrolyte interphase (SEI), showing that TFSI-based ionic liquids (ILs) rank among the best candidates for long-lasting Li-air cells.
A Study of the Influence of Lithium Salt Anions on Oxygen Reduction Reactions in Li-Air Batteries
Journal of the Electrochemical Society
The influence of lithium salts on O 2 reduction reactions (ORR) in 1, 2-dimethoxyethane (DME) and tetraethylene glycol dimethyl ether (TEGDME) has been investigated. Microelectrode studies in a series of tetrabutylammonium salt (TBA salt)/DME-based electrolytes showed that O 2 solubility and diffusion coefficient are not significantly affected by the electrolyte anion. The ORR voltammograms on microelectrodes in these electrolytes exhibited steady-state limiting current behavior. In contrast, peak-shaped voltammograms were observed in Li +-conducting electrolytes suggesting a reduction of the effective electrode area by passivating ORR products as well as migration-diffusion control of the reactants at the microelectrode. FT-IR spectra have revealed that Li + ions are solvated to form solvent separated ion pairs of the type Li + (DME) n PF 6 − and Li + (TEGDME)PF 6 − in LiPF 6-based electrolytes. On the other hand, the contact ion pairs (DME) m Li + (CF 3 SO 3 −) and(TEGDME)Li + (CF 3 SO 3 −) appear to form in LiSO 3 CF 3containing electrolytes. In the LiSO 3 CF 3-based electrolytes the initial ORR product, superoxide (O 2 −), is stabilized in solution by forming [(DME) m-1 (O 2 −)]Li + (CF 3 SO 3 −) and [(TEGDME)(O 2 −)]Li + (CF 3 SO 3 −) complexes. These soluble superoxide complexes are able to diffuse away from the electrode surface reaction sites to the bulk electrolyte in the electrode pores where they decompose to form Li 2 O 2. This explains the higher capacity obtained in Li/O 2 cells utilizing LiCF 3 SO 3 /TEGDME electrolytes.
Ionic liquids as electrolytes for Li-ion batteries--An overview of electrochemical studies
Journal of Power Sources, 2009
The paper reviews properties of room temperature ionic liquids (RTILs) as electrolytes for lithium and lithium-ion batteries. It has been shown that the formation of the solid electrolyte interface (SEI) on the anode surface is critical to the correct operation of secondary lithium-ion batteries, including those working with ionic liquids as electrolytes. The SEI layer may be formed by electrochemical transformation of (i) a molecular additive, (ii) RTIL cations or (iii) RTIL anions. Such properties of RTIL electrolytes as viscosity, conductivity, vapour pressure and lithium-ion transport numbers are also discussed from the point of view of their influence on battery performance.
Investigation of Ether-Based Ionic Liquid Electrolytes for Lithium-O2 Batteries
Journal of the Electrochemical Society, 2014
In this work, we showed the results of the characterization of ether based electrolytes for Li-O 2 batteries, prepared by mixing TEGDME and N-methoxyethyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)-imide ionic liquid (IL). The mixtures having different ratio TEGDME/IL and containing LiCF 3 SO 3 salt, were thoroughly characterized by thermal analysis, conductivity and electrochemical stability measurements. Their potential use as electrolytes in Li-O 2 batteries was checked investigating Li/TEGDME-IL/O 2 cells by means of cycling voltammetry (CV) and galvanostatic charge-discharge tests.
The Journal of Physical Chemistry Letters, 2013
Polyether solvents are considered interesting and important candidates for Li−O 2 battery systems. Discharge of Li−O 2 battery systems forms Li oxides. Their mechanism of formation is complex. The stability of most relevant polar aprotic solvents toward these Li oxides is questionable. Specially high surface area carbon electrodes were developed for the present work. In this study, several spectroscopic tools and in situ measurements using electrochemical quartz crystal microbalance (EQCM) were employed to explore the discharge−charge processes and related side reactions in Li−O 2 battery systems containing electrolyte solutions based on triglyme/lithium bis-(trifluoromethanesulfonyl)imide (LiTFSI) electrolyte solutions. The systematic mechanism of lithium oxides formation was monitored. A combination of Fourier transform infrared (FTIR), NMR, and matrix-assisted laser desorption/ionization (MALDI) measurements in conjunction with electrochemical studies demonstrated the intrinsic instability and incompatibility of polyether solvents for Li−air batteries. SECTION: Energy Conversion and Storage; Energy and Charge Transport
In this work, the electrochemical stability and lithium plating/stripping performance of N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (Pyr 14 TFSI) are reported, by investigating the behavior of Li metal electrodes in symmetrical Li/electrolyte/Li cells. Electrochemical impedance spectroscopy measurements and galvanostatic cycling at different temperatures are performed to analyze the influence of temperature on the stabilization of the solid electrolyte interphase (SEI), showing that TFSI-based ionic liquids (ILs) rank among the best candidates for long-lasting Li-air cells.
New Electrode and Electrolyte Configurations for Lithium-Oxygen Battery
Chemistry - A European Journal, 2018
We report herein cathode configurations alternative to the most diffused ones for application in lithium-oxygen batteries using an ionic liquid-based electrolyte. The electrodes employ high surface area conductive carbon as the reaction host and polytetrafluoroethylene as the binding agent to enhance ORR/OER reversibility. Roll-pressed, self-standing electrodes (SSEs) and thinner, spray deposited electrodes (SDEs) are characterized in lithium-oxygen cells using an ionic liquid (IL) based electrolyte formed by mixing lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salt in N,N-diethyl-N-(2-methoxyethyl)-N-methylammonium bis(trifluoromethanesulfonyl)imide (DEMETFSI). The electrochemical results reveal reversible reaction for both electrode