New Electrode and Electrolyte Configurations for Lithium-Oxygen Battery.

Cathode configurations reported herein are 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 the oxygen reduction reaction (ORR)/oxygen evolution reaction (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 and N,N-diethyl-N-(2-methoxyethyl)-N-methylammonium bis(trifluoromethanesulfonyl)imide (DEMETFSI).

Low-Polarization Lithium-Oxygen Battery Using [DEME][TFSI] Ionic Liquid Electrolyte.

The room-temperature molten salt mixture of N,N-diethyl-N-(2-methoxyethyl)-N-methylammonium bis(trifluoromethanesulfonyl) imide ([DEME][TFSI]) and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salt is herein reported as electrolyte for application in Li-O batteries. The [DEME][TFSI]-LiTFSI solution is studied in terms of ionic conductivity, viscosity, electrochemical stability, and compatibility with lithium metal at 30 °C, 40 °C, and 60 °C. The electrolyte shows suitable properties for application in Li-O battery, allowing a reversible, low-polarization discharge-charge performance with a capacity of about 13 Ah g-1carbon in the positive electrode and coulombic efficiency approaching 100 %.

A Long-Life Lithium Ion Battery with Enhanced Electrode/Electrolyte Interface by Using an Ionic Liquid Solution.

In this paper, we report an advanced long-life lithium ion battery, employing a Pyr14 TFSI-LiTFSI non-flammable ionic liquid (IL) electrolyte, a nanostructured tin carbon (Sn-C) nanocomposite anode, and a layered LiNi1/3 Co1/3 Mn1/3 O2 (NMC) cathode. The IL-based electrolyte is characterized in terms of conductivity and viscosity at various temperatures, revealing a Vogel-Tammann-Fulcher (VTF) trend. Lithium half-cells employing the Sn-C anode and NMC cathode in the Pyr14 TFSI-LiTFSI electrolyte are investigated by galvanostatic cycling at various temperatures, demonstrating the full compatibility of the electrolyte with the selected electrode materials.

Interphase Evolution of a Lithium-Ion/Oxygen Battery.

A novel lithium-ion/oxygen battery employing Pyr14TFSI-LiTFSI as the electrolyte and nanostructured LixSn-C as the anode is reported. The remarkable energy content of the oxygen cathode, the replacement of the lithium metal anode by a nanostructured stable lithium-alloying composite, and the concomitant use of nonflammable ionic liquid-based electrolyte result in a new and intrinsically safer energy storage system. The lithium-ion/oxygen battery delivers a stable capacity of 500 mAh g(-1) at a working voltage of 2.

Fluorosulfonyl-(trifluoromethanesulfonyl)imide ionic liquids with enhanced asymmetry.

New ionic liquids with an asymmetric anion, fluorosulfonyl-(trifluoromethanesulfonyl)imide (FTFSI), were prepared and their chemical-physical properties were investigated. The ionic liquids based on N-methyl-N-propylpyrrolidinium, PYR(13), N-butyl-N-methylpyrrolidinium, PYR(14), and N-methoxyethyl-N-methylpyrrolidinium, PYR(12O1), exhibit high electrochemical stability (>5.5 V on platinum) and thermal stability (>250 °C in N(2) and >200 °C in O(2)).