The invention discloses a preparation method of a
lithium-
sulfur battery negative
electrode biological carbon material. The preparation method includes the steps: adding
dandelion into water, adding concentrated acid into mixture to perform reaction, diluting the mixture to be neutral, and filtering and
drying the mixture to obtain a product C; adding concentrated acid and water into the product C, placing mixture into a
hydrothermal reaction kettle to perform reaction of solution D, diluting the solution D to be neutral, and filtering and
drying the solution D to obtain a product E; uniformlylaying conductive
graphite on the product, and performing heating reaction in a
tube furnace to obtain a product F; performing flushing, extraction
filtration and
drying on the product F top obtain aproduct G; mixing the product G and powdered
sulfur to obtain a mixture H; placing the mixture H into the
tube furnace to perform heating reaction to obtain the biological carbon negative
electrode material. According to the method, the
dandelion serves as a
biomass raw material, the
dandelion is presoaked by mixed acid, a biological carbon precursor is prepared by a hydrothermal method, activation time is controlled in late activation process, the biological carbon material suitable for
sulfur storage is acquired in a adjusting and controlling manner, the biological carbon material is applied to a
lithium-sulfur battery, and the electrochemical performance of the
lithium-sulfur battery is improved.