Lithium Peroxide-Carbon Composite Cathode for Closed System Li-O2 Batteries

Research interests in batteries with high energy densities have intensified to meet the increasing demand for energy storage mediums for vehicle electrification and portable electronics. Lithium-oxygen (Li-O-2) batteries have garnered significant attention as they provide comparable energy density to gasoline. Studies with open systems in which oxygen is continuously supplied to the cathode have produced fruitful data that have significantly advanced our understanding on rechargeable Li-O-2 batteries. In this study we present a rechargeable Li-O-2 battery in a closed system without oxygen supply, in which a Li2O2-carbon composite is used as starting material in a binder-free cathode configuration. This system shows high discharge capacities based on Li2O2, good rate capability, and reversibility with high Coulombic efficiency. We also demonstrate the capability of the Li2O2-carbon composite cathode to be coupled with a graphite anode. Such a configuration is useful for better understanding the process in the first charge of Li2O2 in Li-O-2 batteries. (C) 2015 The Electrochemical Society. All rights reserved.