Method for preparing modified graphene and method for preparing slurry containing the modified graphene

A method for preparing a modified graphene, comprising the following steps:

• S1:
• putting a flake graphite powder, a silicon molecular modifier, water and a boric acid solution with a molar concentration of 1-2 mol/L into a high pressure container, sealing the container, and forming a vacuum ranging from 0.09 to 0.1 MPa;
• S2:
• filling at least one liquid gas chosen from liquid carbon dioxide, liquid ozone, and liquid nitrogen into the high pressure container in step S1, shaking and then letting the container stand for 20-28 hours;
• S3:
• connecting the high pressure container in step S2 to a solid gas preparation apparatus, to solidify the liquid gas and obtain a solid gas;
• S4:
• putting the solid gas obtained in step S3 into a ultraviolet washing machine with wavelengths of 185 nm and 254 nm in sequence for ultraviolet high-energy radiation, exfoliating the flake graphite powder to obtain a modified graphene flake, and functionally modifying the modified graphene flake with the solid gas to form carbonyl groups and carbon hydroxyl groups on the surface of the modified graphene flake, and grafting the carbonyl groups and carbon hydroxyl groups with silicon hydroxyl groups to obtain a crude modified graphene;
• and
• S5:
• exposing the crude modified graphene obtained in step S4 to ultraviolet light for 20-60 minutes while functionally modifying as described in step S4 to form carbonyl groups and carbon hydroxyl groups on the surface of the crude modified graphene, and grafting the carbonyl groups and carbon hydroxyl groups with silicon hydroxyl to form a modified graphene.

A method for preparing a silicon-titanium modified graphene slurry, comprising the following steps:

• S1:
• adding a nano-titanium powder, a silane coupling agent and an organic solvent into a container, mixing, adding a modified graphene prepared according to claim 1 into the container, dispersing the contents of the container with ultrasound, and adding water to the container,
• wherein the silicon molecular modifier used in the preparation of the modified graphene prepared according to claim 1 has functional groups and the silane coupling agent has functional groups different from the functional groups of the modified graphene;
• and
• S2:
• autoclaving at 110-120° C. for 6-12 hours to obtain a silicon-titanium modified graphene slurry.