Abstract 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 “carbon-concrete” 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 μm 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 μm thickness exhibited 5.3 GPa mechanical strength, specific area of 830 m2/g and broad pore size distribution. This light carbon material could be potentially used for integrating supercapacitor energy storage with automobiles.

中文翻译：

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石墨烯集成碳纤维和分级多孔碳形成坚固的柔性“碳混凝土”超级电容器薄膜

摘要 全碳电极是超级电容器的理想选择，但合成宏观级 >3 GPa 的强多孔碳电极具有挑战性。在这里，我们提出了一种合成坚固的柔性“碳-混凝土”薄膜的方法，该薄膜集成了碳纤维、石墨烯和分级多孔活性炭。该方法涉及碳纤维束的电化学扩散和纤维素涂层的原位活化。发现 10-30 μm 大字面尺寸的电化学剥离石墨烯薄片可以在原位固定单个碳纤维层和保护碳纤维免受活化腐蚀方面发挥关键作用。40 μm 厚的新型柔性多孔“碳-混凝土”薄膜具有 5.3 GPa 的机械强度、830 m2/g 的比表面积和宽孔径分布。