The effect of electrolyte on the electrochemical properties of Na/alpha-NaMnO2 batteries

Abstract

Pure ce-NaMnO2 cathode materials were prepared by solid-state reaction with Mn2O3 and Na2CO3 at 750 degrees C. Electrochemical properties of Na/alpha-NaMnO2 battery was investigated with electrolytes as 1 M NaCIO4 EC/DEC and 1 M NaBF4TEGDME. First discharge capacity of Na/alpha-NaMnO2 cell using 1 M NaC104 EC/DEC electrolyte and 1 M NaBEI TEGDME electrolyte was 146 mAh g(-1) and 136 mAh g(-1) discharge capacity for the first cycle at 0.2 C rate and 104 mAh g(-1), 97 rnAh r1 after 20 cycles, respectively. Na! et-NaMn02 battery with 1 M NaCIO4 EC/DEC electrolyte shows higher initial charge/discharge capacity than that using 1 M NaBF4 TEGDME because of high ionic conductivity of electrolyte and low interfacial resistance between the electrolyte and electrode. However, Na/or-NaMnO2 battery with 1 M NaBF4 TEGDME electrolyte has better stability for the 20th cycle from coulombic efficiency result because of stability of interfacial resistance. (C) 2014 Elsevier Ltd. All rights reserved.