▎ 摘　　要

NOVELTY - A graphene nanomaterial composite comprises 15 pts. wt. modified graphene oxide, 28 pts. wt. carboxymethyl chitosan, 8 pts. wt. tin dioxide and 7 pts. wt. oxidized dextran. The graphene nano-material composite is prepared by mixing (i) carboxymethyl chitosan and dextran in beaker, and adding water 20 times the mass of carboxymethyl chitosan to the beaker to obtain mixed solution, adding mixed solution into hydrochloric acid solution, stirring and dispersing to obtain the microsphere blank dispersion liquid, adjust the pH of the microsphere blank dispersion liquid to neutral with 5 mass% aqueous ammonia, and adding a mixed crosslinking agent solution of 1 times the mass of the microsphere blank dispersion to the microsphere blank dispersion liquid, filtering to obtain a filter cake, and drying the filter cake to obtain microspheres, mixing (ii) graphene oxide and water, mixing (iii) microspheres with a sodium acetate buffer solution, and mixing (iv) modified microsphere with tin source. USE - Graphene nanomaterial composite used for lithium battery electrodes. ADVANTAGE - The graphene nanomaterial composite has excellent electrochemical performance, and coulombic efficiency. DETAILED DESCRIPTION - A graphene nanomaterial composite comprises 15 pts. wt. modified graphene oxide, 28 pts. wt. carboxymethyl chitosan, 8 pts. wt. tin dioxide and 7 pts. wt. oxidized dextran. The graphene nano-material composite is prepared by mixing (i) carboxymethyl chitosan and dextran in beaker at a mass ratio of 5:1, and adding water 20 times the mass of carboxymethyl chitosan to the beaker at a temperature of 30 degrees C and a rotation speed of 380 rpm for 30 minutes to obtain mixed solution, adding mixed solution into 8 %mass hydrochloric acid solution at a rate of 8 mL/min, stirring and dispersing for 60 minutes at a speed of 280 rpm to obtain the microsphere blank dispersion liquid, adjust the pH of the microsphere blank dispersion liquid to neutral with 5 mass% aqueous ammonia, and adding a mixed crosslinking agent solution of 1 times the mass of the microsphere blank dispersion to the microsphere blank dispersion liquid, stirring and reacting for 4 hours at 40 degrees C and a rotation speed of 300 rpm, filtering to obtain a filter cake, and drying the filter cake at a temperature of 65 degrees C for 2 hours to obtain microspheres, mixing (ii) graphene oxide and water in mass ratio of 1:200, and ultrasonically dispersing for 30 minutes at a frequency of 55kHz to obtain a graphene oxide dispersion, using 10% aqueous ammonia to adjust the graphene oxide dispersion pH to 10, adding 0.1 times the mass of the graphene oxide dispersion to the graphene oxide dispersion liquid, stirring and reacting for 6 hours under temperature of 45 degrees C and a rotation speed of 320 rpm, and then filtering to obtain a modified graphene oxide blank, then drying blank at 80 degrees C for 2 hours to obtain modified graphene oxide, mixing (iii) microspheres obtained in step (i) with a sodium acetate buffer solution with a pH of 3.6 in a flask at a mass ratio of 1:10, and adding potassium periodate 0.2 times the mass of the microspheres to the flask, stirring and reacting for 3 hours at 45 degrees C at a speed of 400 rpm, filtering to obtain pretreated microspheres, mixing modified graphene oxide obtained in step (ii) with water at a mass ratio of 1:100, and ultrasonically dispersing for 30 minutes at a frequency of 45 kHz to obtain a modified graphene oxide dispersion, and mixing modified graphene oxide dispersion with pre-treated microspheres in mass ratio of 20:1, stirring and reacting for 180 minutes at 50 degrees C and a rotation speed of 300 rpm, and filtering to obtain a pre-modified microsphere blank, and drying pre-modified microsphere blank for 2 hours at 80 degrees C to obtain modified microspheres, and mixing (iv) the modified microspheres obtained in step (iii) with the tin source aqueous solution at a mass ratio of 1:15, stirring and reacting for 100 minutes at a temperature of 30 degrees C and a rotation speed of 420 rpm, and then filtering to obtain a composite blank, mixing composite blank with 8% sodium hydroxide solution in a mass ratio of 1:8, stirring and reacting at a temperature of 40 degrees C for 3 hours, and then filtering to obtain a pretreated composite blank, carbonizing material blank at a temperature of 600 degrees C for 6 hours, discharging to obtain a graphene nanomaterial composite for lithium electronic battery electrodes, and performing (v) index analysis on the graphene nanomaterial composite for lithium electronic battery electrodes. The mixed crosslinking agent solution is mixing glutaraldehyde and formaldehyde in a mass ratio of 1:1, adding water 36 times the mass of glutaraldehyde, stirring and dispersing to obtain a mixed crosslinking agent solution. The tin source aqueous solution is a 12 %mass tin dichloride aqueous solution or 10 %mass tin tetrachloride aqueous solution.