Enhanced Electrolyte Utilizing Fluorocarbon Additives

Abstract

Perfluorocarbons, the main component of artificial blood, have been investigated as additives for lithium oxygen battery due to their ability to absorb significant volume of oxygen. They are expected to increase the amount of oxygen dissolved in the electrolyte and therefore decrease the polarization during discharge. In this work, fluorocarbon compound (PFC) is incorporated in the ether electrolytes and its performance is tested in lithium oxygen battery. Our results demonstrate that addition of PFC improves the discharge voltage significantly up to 200mV for 20% PFC addition in 0.1 M LiClO4:TEGDME electrolyte. We also discover that the effect of PFC additives is more pronounce at thicker electrode, signifying that PFC additives might enhance the concentration of oxygen and or diffusion of oxygen throughout the electrode thickness. To further investigate the effect of altering oxygen solubility, the pressure of the system was varied. The impedance spectroscopy demonstrates that the charge transfer resistance value decreases with addition of PFC, decrease of cathode thickness and increase of pressure. Further result from rotating ring disk in order to quantify the concentration of oxygen soluble in the electrolyte and its difussion coefficient will be presented. This novel approach of utilizing the phenomenal characteristics of perfluorocarbon reveals an unconventional approach towards enhancing the lithium O2 battery performance.