The present invention relates to the technical field of battery materials, and in particular to a
nitrogen-
sulfur co-doped hard carbon negative
electrode material for
sodium /
potassium ion batteries and a preparation method thereof. The preparation method comprises preparing a mixture
powder of dodecyl
sulfonate and a
nitrogen source, carbonizing under
inert gas conditions, washing the carbonized product, and
vacuum drying to obtain a
nitrogen-
sulfur co-doped hard carbon negative
electrode material. The introduction of nitrogen atoms in the negative
electrode material prepared by the present invention can change the
surface charge distribution of the carbon material, improve the
electronic conductivity, and at the same time increase the active sites, and promote the capacitive adsorption behavior of the carbon material for
sodium /
potassium ions; the introduction of
sulfur atoms can increase the hard carbon interlayer spacing, reduce the
sodium /
potassium ion diffusion energy barrier, enhance the
diffusion kinetics behavior, and synergistically improve the sodium / potassium storage performance of the hard carbon material. The above-mentioned negative
electrode material can be used to prepare sodium / potassium
ion batteries with high specific capacity, excellent rate performance and long cycle stability, and the preparation method is simple in process, controllable in large quantities, low in cost, and
environmentally friendly.