▎ 摘　　要

It is highly desirable to develop industrially scalable methods to produce defect-free graphene to meet the requirement of graphene from lab to commercial applications. In this paper, a ball-milling in series with a shear mixing exfoliation technique in supercritical CO2 was developed. Graphite was pretreated by ball-milling in supercritical CO2, and the exfoliated sheets with smaller lateral sizes and numerous crevices on their edges were elutriated into a shear-mixing vessel by supercritical CO2 simultaneously to inhibit over crushing. Whereafter, the freshly exfoliated sheets with crevices were further exfoliated into few-layer graphene without aggregation. 90% of the obtained graphene was less than five layers, and the processing capacity of 40 g for one batch increased 40-100 times compared with the previously reported method. The electrical conductivity of 3.25 x 10(5) S/m of the flexible graphene film on PVDF substrate demonstrates the excellent electrical performance of the obtained graphene.