Graphene possesses extraordinary mechanical, electronic, and thermal properties, thus making it one of the most promising building blocks for constructing macroscopic high performance and multifunctional materials. However, the common material strength–ductility paradox also appears in the carbon-nanoarchitected materials and some of the key mechanical performance, for example, the tensile strength of graphene-based materials, are still far lower than that of graphene. Inspired by the exceptional mechanical performance of silk protein benefiting from the conformations of folded structures as well as their transitions, this work proposed a topological strategy to yield graphene-based materials with ultrahigh ductility while maintaining decent tensile strength by self-folding graphene sheets. This drastically improved mechanical performance of graphene-based materials is attributed to the exploitation of shearing, sliding, and unfolding deformation at the self-folded interface. Molecular dynamics simulations show that both modulating self-folded length and engineering interface interaction can effectively control the strength, ductility, and the ductile failure of van der Waals interfaces among the self-folded structures, where interfacial shearing, sliding, and unfolding open channels to dissipate mechanical energy. Based on the insights into the atomic-scale deformation by molecular dynamics simulations, the underlying mechanism of deformation and failure of these materials is finally discussed with a continuum mechanics-based model. Our findings bring perceptive insights into the microstructure design of strong-yet-ductile materials for load-bearing engineering applications.

石墨烯具有非凡的机械，电子和热学性质，因此使其成为构建宏观高性能和多功能材料的最有希望的组成部分之一。但是，碳纳米结构材料中也出现了常见的材料强度-延性悖论，并且某些关键的机械性能（例如，石墨烯基材料的拉伸强度）仍远低于石墨烯。得益于折叠结构的构象及其过渡，丝蛋白具有出色的机械性能，这项工作提出了一种拓扑策略，以生产具有超高延展性的石墨烯基材料，同时通过自折叠石墨烯片保持适当的拉伸强度。石墨烯基材料机械性能的大幅提高归因于自折叠界面处的剪切，滑动和展开变形。分子动力学模拟表明，调节自折叠长度和工程界面相互作用均可有效地控制自折叠结构之间范德华斯界面的强度，延展性和延性破坏，其中界面剪切，滑动和展开的开放通道耗散机械能。基于分子动力学模拟对原子尺度形变的认识，最后使用基于连续力学的模型讨论了这些材料形变和破坏的潜在机理。