▎ 摘　　要

NOVELTY - A large-sized graphene with high quality and controllable layer number is prepared by stirring graphite powder or crystalline flake graphite and intercalating agent, repeatedly washing with water and acetone, filtering, drying to give different orders of graphite intercalation compound (GICs), adding GIC expanding agent with or without adjuvant, leaching in which interlayer material expanding agent or adjuvant reaction releases gas and expands the interlayer distance between graphene sheets, adding appropriate treatment agent, ultrasonically shearing or ball-milling, and centrifuging. USE - Preparation of large-sized graphene with high quality and controllable layer number (claimed). ADVANTAGE - The process does not involve oxidation-reduction of graphite, does not use strong reducing agent, and does not need pure hydrogen reduction and high temperature condition which avoids danger of explosion. Raw material is cheap, stripping process requires mild reaction conditions and does not damage graphene structure, graphene layer number can be accurately controlled, and graphene sheet with small defect, large size, high electrical conductivity, and high yield and quality can be obtained. DETAILED DESCRIPTION - A large-sized graphene with high quality and controllable layer number is prepared by stirring graphite powder or crystalline flake graphite having size of 10-500 mu m and intercalating agent at 10-130 degrees C for 5 minutes to 48 hours, repeatedly washing with water and acetone, filtering, drying at 50-100 degrees C for 2-24 hours to give different orders of graphite intercalation compound (GICs) in which molar ratio of graphite powder or crystalline flake graphite with intercalating agent is 1:0.05-12, adding GIC expanding agent with or without adjuvant, leaching for 5-7 hours at 20-100 degrees C in which interlayer material expanding agent or adjuvant reaction releases gas and expands the interlayer distance between graphene sheets, adding appropriate treatment agent to form highly inflated worm-shaped graphene aggregates, ultrasonically shearing or ball-milling resulting graphene aggregates, and centrifuging to obtain different quality layers. Ultrasonic power is 50-1600 W, ultrasonic time is 5 minutes to 2 hours, cutting rotating speed is 10-28000 rpm, shearing time is 10 minutes to 5 hours, ball-milling rotating speed is 200-1600 rpm, ball-milling time is 1-6 hours, centrifugal rotating speed is 500-12000 rpm, and centrifugal time is 5 minutes to 1 hour. DESCRIPTION OF DRAWING(S) - The drawing shows an optical microscopic image of a GIC with small defect sheet and low degree of oxidation.