High-voltage honeycomb layered oxide positive electrodes for rechargeable sodium batteries

Honeycomb layered oxides from Na2Ni2–xCoxTeO6 family were assessed for use as positive electrodes in rechargeable sodium batteries at ambient and elevated temperatures using ionic liquids. Substitution of nickel with cobalt increases the discharge voltage to nearly 4 V (versus Na+/Na), surpassing the average voltages of most Na based layered oxide positive electrodes.