Delocalized electrochemical exfoliation toward high-throughput fabrication of high-quality graphene

Many of graphene’s industrial applications such as electromagnetic interference (EMI) shielding demand efficient fabrication of high-quality graphene in large scale. Existing electrochemical exfoliation is a trade-off but never an ideal solution in this regard. Herein, we propose a delocalized electrochemical exfoliation (DEE) strategy to revolutionize the way graphite is electrochemically exfoliated. By transmitting the electric potentials with electron transfer reactions, the electrochemical exfoliation is firstly delocalized from electrode/electrolyte interfaces to the whole electrolyte system, thus making deep yet non-destructive exfoliation possible for every dispersed graphite particle. The as-prepared DEE-graphene possesses an ultralow defect density (~1.3 × 1010 cm−2) and significantly high carbon-to-oxygen ratio (~28). Remarkably, record high yields (greater than 98%, 1–10 layers) and production rates (~72.7 g h−1) are achieved in up-scaled DEE in a reproducible manner. More importantly, processing this high-quality graphene into membranes with optimal orientation brings a superior EMI shielding performance (1.9 × 105 dB cm2 g−1) outperforming the best membranes fabricated from metals and many other 2-D materials including reduced graphene oxide and MXenes. The highly efficient DEE with a fundamentally different mechanism and the effective orientation angle modulation strategy for EMI shielding would inspire research and applications of graphene and other two-dimensional materials.