Showing papers by "Edward J. Plichta published in 2013"
TL;DR: In this article, Dimethyl sulfoxide (DMSO) was evaluated as a practical solvent for the rechargeable lithium air battery and its reduction products in the presence of LiPF6 supporting electrolyte via cyclic, rotating disk (RDE) and ring-disk (RRDE) electrode voltammetry.
Abstract: Dimethyl Sulfoxide (DMSO) was evaluated as a practical solvent for the rechargeable lithium air battery. Redox characteristics of the dissolved oxygen and its reduction products in the presence of lithium hexafluorophosphate (LiPF6) supporting electrolyte were studied via cyclic, rotating disk (RDE) and ring-disk (RRDE) electrode voltammetry. The DMSO medium facilitates reversible reduction and oxidation processes in contrast to other solvent-based electrolytes studied. Galvanostatic discharge-charge cycling of the Li-O2 cells has shown characteristics of rechargeability expected from voltammetric studies. Multiple high-efficiency dischargecharge cycles are possible if the depth of discharge of the carbon cathode is limited to avoid excessive passivation by the discharge products. The discharge voltage of this Li-O2 cell is higher than cells assembled with other non-aqueous organic electrolytes, an attribute ascribed to the stability of superoxide (O2−), the one-electron reduction product of oxygen. © 2012 The Electrochemical Society. [DOI: 10.1149/2.048302jes] All rights reserved.
251 citations
TL;DR: In this article, the authors reported the full reduction of O2 to Li2O in a Li-air cell using cobalt phthalocyanine catalyzed carbon cathodes.
Abstract: The full reduction of O2 to Li2O is the ultimate chemistry desired for building a super high energy density Li-air battery. Most investigations to date have identified Li2O2 as the discharge product which limits the specific energy of the Li-air battery to 3500 Wh kg−1, about 67% of the theoretical value. Here, for the first time, we report the full reduction of O2 to Li2O in a Li-air cell using cobalt phthalocyanine catalyzed carbon cathodes. Details of the oxygen reduction reaction mechanism have been discerned through cyclic voltammetry experiments in half cells as well as analysis of discharged Li-air cell cathodes by means of X-ray absorption spectroscopy and X-ray diffraction. The catalyst lowers the activation energy for O2 reduction by forming a complex with superoxide, and enables the reduction of Li2O2 to Li2O. In addition, the catalyst is effective in lowering the gap between the discharge and charge voltage plateaus leading to an increase in the energy efficiency of the Li-air battery. The breakthrough in the discharge chemistry being reported could lead to the realization of the full potential of the Li-air battery. © 2013 The Electrochemical Society. [DOI: 10.1149/2.118309jes] All rights reserved.
50 citations
27 citations
08 Mar 2013
TL;DR: In this paper, the performance of an iron- chloride redox flow battery for grid-scale applications was studied, and the authors focused on the performance improvement of the battery for the integration of renewable energy sources like solar and wind into the electricity grid.
Abstract: Large scale energy storage systems that are inexpensive, robust, and highly efficient are necessary for the integration of renewable energy sources like solar and wind into the electricity grid [1]. Electrochemical energy storage systems, especially batteries offer a very promising solution for grid scale applications [2]. The present study focuses on studying the performance of an iron – chloride redox flow battery for grid-scale applications.
1 citations