▎ 摘　　要

NOVELTY - Preparing MXene/reduced graphene oxide (MXene/rGO)-biochar hydrogel composite material comprises soaking the freeze-dried biomass material in a mixed dispersion of MXene and graphene oxide (GO) to fully absorb, adding ethylenediamine into the mixed dispersion, carrying out hydrothermal reaction, heating to 80-130degrees Celsius for 6-48 hours, washing with de-ionized water and ethanol in complete reaction of ethylene diamine, cleaning and vacuum heating to 50-70degrees Celsius, and keeping the temperature until drying, reducing the temperature to room temperature, taking out to obtain the dried mixture, sintering and carbonizing the dried mixture under the protection of inert gas, cooling to room temperature and taking out, heating to 600-800degrees Celsius for 1-2 hours, grinding the carbonized mixture in a ball mill for 20-30 minutes, adding activating agent and water and mixing uniformly, drying at 40-60degrees Celsius, sintering and activating under the protection of inert gas, and grinding the product. USE - Preparation method of MXene/rGO-based composite material for electrode sheet used in electronic device such as miniature, portable and highly integrated electronic device. ADVANTAGE - The inventive method combines MXene/rGO hydrogel and biological carbon frame. The innovative structure can effectively overcome the defect of MXene self-stacking, providing active site of pseudo-capacitor, and performing pore-forming by carbonization and KOH activation, effectively increasing specific surface area of the composite material. It improves specific capacitance and energy density when applied to super capacitor. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for an electrode sheet using MXene/rGO biochar hydrogel composite material.