High Voltage Performances of Li2NiPO4F Cathode with Dinitrile-Based Electrolytes

A sebaconitrile-based electrolyte, 1 M LiBF4/ethylene carbonate-dimethyl carbonate-sebaconitrile (25:25:50 by vol%) exhibits excellent electrochemical stability above 6 V against Li/Li+. To confirm that the electrolyte can work at high voltages, LiFePO4 was intentionally charged at 6 V vs Li/Li+. After the 6 V charging, the discharge capacity was 137 mAh/g and the coulomb efficiency was 91%. In addition, this oxidation resistant electrolyte was able to prove that Li2NiPO4F has actually ca. 5.3 V redox potential against Li anode through cyclic voltammetry and charge/discharge cycle test. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3417068] All rights reserved.