Graphene has attracted more and more attention worldwide since it possesses the excellent physical and chemical properties. Recently, a variety of methods for the production of graphene have been reported in order to develop potential practical applications. However, these methods each have their own unique disadvantages. Such as, micromechanical cleavage is too expensive and time-consuming to be applicable for mass production though its quality is great. CVD method can make large-area graphene film, but due to its high cost, it could not find applications in the production of polymer composite, conductive ink, coating materials, thermal materials, lithium Ion cell, et al. because these fields require mass amount of product. Though the technique of chemical reduction of graphene oxide (RGO) can produce mass graphene, it has inherent weak due to its oxygen-containing groups and disruption of the basal plane of graphene, heavily damaging its electronic performance. Therefore, it is highly desirable to explore new routes to make massively production of graphene with low-cost but high quality. 

In this report, we present a novel strategy developed in our lab for massive production of defect-free graphene with cost-efficiency. We have directly exfoliated natural flake graphite into the pristine graphene using supercritical CO2 assisted with other technology. The characterization results by AFM, Raman, TEM, IR and XRD, etc. demonstrate that the graphene with layer numbers of 1-3 and lateral size of 0.5−5.0 μm is more than 94%. The yield of the graphene attains more than 60%. We have also carried out some investigations on applications of the as-produced graphene. The film made from the exfoliated graphene has a high electrical conductivity of 2.8 × 107 S/m. We have used this exfoliated pristine graphene to formulate the ink for fabricating electrodes. The ink is highly stable for more than nine months. Therefrom, the printed electrodes have high conductivity. The as-produced graphene sheets can heighten the electrochemical performance of LiFePO4 cathode materials. The specific capacity of the LiFePO4/graphene composite cathode achieves more than 160 mAh/g and displays good stable cycling cycles. Our study on anti-corrosion of graphene to metal demonstrates the as-produced graphene can assemble on the surface of the metal, and protect it from acid solution corrosion. The results demonstrate that the graphene produced by our novel and simple technology has a good quality, and can widely applied in conductive ink, battery materials, polymer composite and coating materials. 

Graphene has attracted more and more attention worldwide since it possesses the excellent physical and chemical properties. Recently, a variety of methods for the production of graphene have been reported in order to develop potential practical applications. However, these methods each have their own unique disadvantages. Such as, micromechanical cleavage is too expensive and time-consuming to be applicable for mass production though its quality is great. CVD method can make large-area graphene film, but due to its high cost, it could not find applications in the production of polymer composite, conductive ink, coating materials, thermal materials, lithium Ion cell, et al. because these fields require mass amount of product. Though the technique of chemical reduction of graphene oxide (RGO) can produce mass graphene, it has inherent weak due to its oxygen-containing groups and disruption of the basal plane of graphene, heavily damaging its electronic performance. Therefore, it is highly desirable to explore new routes to make massively production of graphene with low-cost but high quality. 

In this report, we present a novel strategy developed in our lab for massive production of defect-free graphene with cost-efficiency. We have directly exfoliated natural flake graphite into the pristine graphene using supercritical CO2 assisted with other technology. The characterization results by AFM, Raman, TEM, IR and XRD, etc. demonstrate that the graphene with layer numbers of 1-3 and lateral size of 0.5−5.0 μm is more than 94%. The yield of the graphene attains more than 60%. We have also carried out some investigations on applications of the as-produced graphene. The film made from the exfoliated graphene has a high electrical conductivity of 2.8 × 107 S/m. We have used this exfoliated pristine graphene to formulate the ink for fabricating electrodes. The ink is highly stable for more than nine months. Therefrom, the printed electrodes have high conductivity. The as-produced graphene sheets can heighten the electrochemical performance of LiFePO4 cathode materials. The specific capacity of the LiFePO4/graphene composite cathode achieves more than 160 mAh/g and displays good stable cycling cycles. Our study on anti-corrosion of graphene to metal demonstrates the as-produced graphene can assemble on the surface of the metal, and protect it from acid solution corrosion. The results demonstrate that the graphene produced by our novel and simple technology has a good quality, and can widely applied in conductive ink, battery materials, polymer composite and coating materials.