Simultaneous Electrochemical Dual-Electrode Exfoliation of Graphite toward Scalable Production of High-Quality Graphene

Developing scalable methods to produce large quantities of high-quality and solution-processable graphene is essential to bridge the gap between laboratory study and commercial applications. Here an efficient electrochemical dual-electrode exfoliation approach is developed, which combines simultaneous anodic and cathodic exfoliation of graphite. Newly designed sandwich-structured graphite electrodes which are wrapped in a confined space with porous metal mesh serve as both electrodes, enabling a sufficient ionic intercalation. Mechanism studies reveal that the combination of electrochemical intercalation with subsequent thermal decomposition results in drastic expansion of graphite toward high-efficiency production of graphene with high quality. By precisely controlling the intercalation chemistry, the two-step approach leads to graphene with outstanding yields (85% and 48% for cathode and anode, respectively) comprising few-layer graphene (1-3 layers, >70%), ultralow defects (I-D/I-C < 0.08), and high production rate (exceeding 25 g h(-1)). Moreover, its excellent electrical conductivity (>3 x 10(4) S m(-1)) and great solution dispersibility in N-methyl pyrrolidone (10 mg mL(-1)) enable the fabrication of highly conductive (11 Omega sq(-1)) and flexible graphene films by inkjet printing. This simple and efficient exfoliation approach will facilitate the development of large-scale production of high-quality graphene and holds great promise for its wide application.