New Electrode and Electrolyte Configurations for Lithium‐Oxygen Battery. Issue 13 (29th January 2018)

• Record Type: Journal Article
• Authors: Ulissi, Ulderico; Elia, Giuseppe Antonio; Jeong, Sangsik; Reiter, Jakub; Tsiouvaras, Nikolaos; Passerini, Stefano; Hassoun, Jusef
• Is Part Of: Chemistry. Volume 24:Issue 13(2018)
• Page Start: 3178
• Page End: 3185
• Publication Date: 2018-01-29
• Subjects: electrochemistry -- ionic liquids -- lithium-oxygen battery -- self-standing electrodes -- spry-deposited electrode; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201704293
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: 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). The electrochemical results reveal reversible reactions for both electrode configurations, but improved electrochemical performance for the self‐standing electrodes in lithium‐oxygen cells. These electrodes show charge/discharge polarizations at 60 °C limited to 0.4 V, with capacity up to 1 mAh cm −2 and energy efficiency of about 88 %, while the spray deposited electrodes reveal, under the same conditions, a polarization of 0.6 V and energy efficiency of 80 %. The roll pressed electrode combined with the DEMETFSI‐LiTFSI electrolyte and a composite Li x Sn‐C alloy anode forms a full Li‐ion oxygen cell showing extremely limited polarization, and remarkable energy efficiency. Abstract : Energy efficient : Li/O2 batteries using ionic liquid based electrolytes are generally favored by a remarkably low OER average potential. In this context, by exploring different cell configurations, including a Li x Sn‐C alloy anode and a self‐standing carbon composite as cathode support, a full Li‐ion oxygen cell showing extremely limited polarization and remarkable energy efficiency is reported.