Electrochemical properties of Na/Ni3S2 cells with liquid electrolytes using various sodium salts

For a Na/Ni3S2 cell operating at room temperature, three kinds of tetra (ethylene glycol) dimethyl ether (TEGDME) electrolytes, containing sodium trifluoromethane sulfonate (NaCF3SO3), sodium hexafluorophosphate (NaPF6), and sodium perchlorate (NaClO4) salts, respectively, were prepared. Na/Ni3S2 cells with 1 M NaCF3SO3 in TEGDME showed a discharge plateau potential of 0.85 V and a first discharge capacity of 448 mAh/g. The discharge capacity decreased to 250 mAh/g after 40 cycles, which represented the best cycling performance among the three electrolytes.