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Mccloskey B.D.,IBM | Valery A.,IBM | Valery A.,Grenoble Institute of Technology | Luntz A.C.,IBM | And 7 more authors.
Journal of Physical Chemistry Letters | Year: 2013

Li-air batteries have generated enormous interest as potential high specific energy alternatives to existing energy storage devices. However, Li-air batteries suffer from poor rechargeability caused by the instability of organic electrolytes and carbon cathodes. To understand and address this poor rechargeability, it is essential to elucidate the efficiency in which O 2 is converted to Li2O2 (the desired discharge product) during discharge and the efficiency in which Li2O 2 is oxidized back to O2 during charge. In this Letter, we combine many quantitative techniques, including a newly developed peroxide titration, to assign and quantify decomposition pathways occurring in cells employing a variety of solvents and cathodes. We find that Li2O 2-induced electrolyte solvent and salt instabilities account for nearly all efficiency losses upon discharge, whereas both cathode and electrolyte instabilities are observed upon charge at high potentials. © 2013 American Chemical Society. Source

Kang S.J.,IBM | Mori T.,Central Glass International Inc. | Suk J.,Korea Research Institute of Chemical Technology | Kim D.W.,Korea Research Institute of Chemical Technology | And 3 more authors.
Journal of Materials Chemistry A | Year: 2014

We demonstrate a facile but very effective approach to improve the cycling efficiency of metallic lithium electrodes by controlling the pore morphology of separators. We employed anodized porous alumina as the model nanoporous separator and demonstrated the improvement of cycle efficiency of lithium electrodes in lithium-oxygen cells. 2014 This journal is © the Partner Organisations. Source

Sanders D.P.,IBM | Sundberg L.K.,IBM | Fujiwara M.,Central Glass International Inc. | Terui Y.,Central Glass International Inc. | Yasumoto M.,Central Glass International Inc.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2010

Fluoroalcohol-containing materials have found considerable use in 193 nm immersion topcoat and topcoat-free immersion resist materials due to their good water contact angles and base-dissolution properties. Trifluoromethanesulfonamide-containing materials are another alternative which have been explored for use in 193 nm photoresist and immersion topcoat applications; however, fluorosulfonamide materials have suffered from issues such as low water contact angles. In this paper, we report the synthesis of a series of fluorosulfonamide-containing methacrylate materials with water contact angle and base dissolution performance that rivals or exceeds that of comparable fluoroalcohol-based materials. © 2010 Copyright SPIE - The International Society for Optical Engineering. Source

Kang S.J.,IBM | Mori T.,Central Glass International Inc. | Narizuka S.,Central Glass International Inc. | Wilcke W.,IBM | Kim H.-C.,IBM
Nature Communications | Year: 2014

Carbon has unfaired advantages in material properties to be used as electrodes. It offers a low cost, light weight cathode that minimizes the loss in specific energy of lithium-oxygen batteries as well. To date, however, carbon dioxide evolution has been an unavoidable event during the operation of non-aqueous lithium-oxygen batteries with carbon electrodes, due to the reactivity of carbon against self-decomposition and catalytic decomposition of electrolyte. Here we report a simple but potent approach to eliminate carbon dioxide evolution by using an ionic solvate of dimethoxyethane and lithium nitrate. We show that the solvate leads to deactivation of the carbon against parasitic reactions by electrochemical doping of nitrogen into carbon. This work demonstrates that one could take full advantage of carbon by mitigating the undesired activity. © 2014 Macmillan Publishers Limited. All rights reserved. Source

McCloskey B.D.,IBM | Bethune D.S.,IBM | Shelby R.M.,IBM | Mori T.,Central Glass International Inc. | And 5 more authors.
Journal of Physical Chemistry Letters | Year: 2012

Quantitative differential electrochemical mass spectrometry (DEMS) is used to measure the Coulombic efficiency of discharge and charge [(e -/O 2) dis and (e -/O 2) chg] and chemical rechargeability (characterized by the O 2 recovery efficiency, OER/ORR) for Li-O 2 electrochemistry in a variety of nonaqueous electrolytes. We find that none of the electrolytes studied are truly rechargeable, with OER/ORR <90% for all. Our findings emphasize that neither the overpotential for recharge nor capacity fade during cycling are adequate to assess rechargeability. Coulometry has to be coupled to quantitative measurements of the chemistry to measure the rechargeability truly. We show that rechargeability in the various electrolytes is limited both by chemical reaction of Li 2O 2 with the solvent and by electrochemical oxidation reactions during charging at potentials below the onset of electrolyte oxidation on an inert electrode. Possible mechanisms are suggested for electrolyte decomposition, which taken together, impose stringent conditions on the liquid electrolyte in Li-O 2 batteries. © 2012 American Chemical Society. Source

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