Self-discharge and transition metal dissolution weaknesses bother the application of LiNi0.5Mn1.5O4 cathode material due to the severe oxidation of electrolyte at the high voltage state. A novel additive, 1-propylphosphonic acid cyclic anhydride (PACA), is desirable to prevent this oxidation. CV and charge-discharge results reveal that adding 0.5% PACA can relieve the oxidation of electrolyte. Consequently, the self-discharge and transition metal dissolution are both suppressed effectively, which is validated by self-discharge tests, XPS, and EDX analyses. Moreover, using PACA as an additive enhances the capacity retention capability of LiNi0.5Mn1.5O4 at elevated temperatures significantly. Crown Copyright (C) 2014 Published by Elsevier B.V. All rights reserved.