The addition of iron to Ni3S2 electrode for sodium secondary battery

In order to investigate the role of iron additive in the Ni3S2 electrode, the Ni3S2 electrode was prepared by addition of iron. The discharge properties of Na/Ni3S2 cells using 1 M NaCF3SO3 in tetra(ethylene glycol)dimethyl ether liquid electrolyte were investigated at room temperature. The Na/Ni3S2 cell had an initial discharge capacity of 400 mAh g−1 with a plateau potential at 0.84 V versus Na/Na+. The discharge capacity decreased to 255 mAh g−1 after 15 cycles. Iron additive in Ni3S2 electrode played a role as a conductive agent and did not form iron sulfide during charging.

► It was reported that Na/Ni3S2 cell showed a high capacity and good cycle life.
► Since iron is an electric conductor and iron-sulfide is a good active material for sodium battery, we prepare Ni3S2 electrode by addition of iron powder.
► Iron powder in the Ni3S2 electrode plays a role as a conductive agent and does not form iron sulfides.