The effects of the addition of cyclic ethers to electrolyte solution were examined to suppress the degradation of graphite negative-electrodes that is caused by the dissolution of Mn ion from Mn-based positive-electrodes into the electrolyte solution. The edge plane of highly oriented pyrolytic graphite (HOPG) was used as a model electrode and its electrochemical properties were investigated by cyclic voltammetry and electrochemical impedance spectroscopy in electrolyte solution containing Mn ion and cyclic ethers. The use of specific kinds of cyclic ethers greatly suppressed the decrease in the redox currents due to the intercalation/de-intercalation reactions of Li+ at the HOPG edge plane and the increase in the interfacial resistance between the HOPG electrode and electrolyte solution, even at a very low molar ratio of cyclic ether/Mn ion = 2.5. (C) 2016 The Electrochemical Society. All rights reserved.