Aprotic rechargeable Li-O2 batteries are currently receiving considerable interest because they can possibly offer significantly higher energy densities than conventional Li-ion batteries. The electrochemical behavior of Li-O2 batteries containing bis(trifluoromethane)sulfonimide lithium salt (LiTFSI)/tetraglyme electrolyte were investigated by galvanostatic cycling and electrochemical impedance spectroscopy measurements. Ex-situ X-ray diffraction and scanning electron microscopy were used to evaluate the formation/dissolution of Li2O2 particles at the cathode side during the operation of Li-O2 cells.
Keywords: Li–O2 batteries; aprotic electrolyte; impedance spectroscopy; scanning electron microscopy.