▎ 摘　　要

High-quality graphene flakes have long been desirable for numerous applications including energy storage, printable electronics, and catalysis. In this contribution, we report a green, efficient, facile gas-driven exfoliation process for the preparation of high-quality graphene in large scale. The gas exfoliation process was realized by the interplay between the expansion of interlayer at high temperature and the gasification of liquid nitrogen within the interlayer. Detailed experiments demonstrated that the higher temperature was critical to the formation of fewer layers. The exfoliated graphene was proved to be of high quality. We further investigated the electrochemical behavior of this exfoliated graphene. As a result, this few-layered graphene demonstrated an enhanced capability as a supercapacitor, much higher than its counterpart parent material. (c) 2017 Published by Elsevier B.V. on behalf of Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences