▎ 摘　　要

All carbon-electrode is ideal for supercapacitor, but synthesizing macro-level >3 GPa strong porous carbon electrode is challenging. Here, we presented an approach of synthesizing robust flexible "carbonconcrete" films integrating carbon fibers, graphene and hierarchical porous activated carbon. The method involved electrochemically spreading of carbon fiber bundles and in-situ activation of cellulose coating layers. It was found that 10-30 mu m large literal size of electrochemically exfoliated graphene flakes could play a key role in in-situ fixing individual carbon fiber layer and protecting carbon fibers from activation corrosion. The new flexible porous "carbon-concrete" film with 40 mm thickness exhibited 5.3 GPa mechanical strength, specific area of 830 m(2)/g and broad pore size distribution. This light carbon material could be potentially used for integrating supercapacitor energy storage with automobiles. (C) 2017 Elsevier Ltd. All rights reserved.