Ether-based electrolytes for the lithium/oxygen organic electrolyte battery

The practical operation of a lithium/oxygen organic electrolyte battery depends on a significant amount of dissolved oxygen transporting through the organic electrolyte permeating the carbon black cathode before its reduction occurs. The rate of oxygen transport directly influences rate capability and discharge capacity. The organic electrolyte can be tailored to maximize the transport of oxygen while still retaining the ability to form a stable solid electrolyte interface with the lithium anode, chemical stability towards the discharge products Li2O2 and Li2O, and oxidative stability to over 3 V. We investigated an ether-based electrolyte containing four different electrolyte salts to determine how electrolyte properties such as oxygen solubility, dynamic viscosity, and conductivity change with each electrolyte salt, and how this directly affects rate capability and discharge capacity. The results indicate that discharge capacity at 0.5 mA/cm(2) is determined by dynamic viscosity alone for these electrolytes, while discharge capacity at 0.2 and 0.05 mA/cm(2) shows no correlation with either oxygen solubility, dynamic viscosity, or conductivity. Our results demonstrate that a substantial improvement in rate capability can be achieved by optimizing electrolyte viscosity. (c) 2005 The Electrochemical Society.