The ingenious design of a freestanding flexible electrode brings the possibility for power sources in emerging wearable electronic devices. Here, reduced graphene oxide (rGO) wraps carbon nanotubes (CNTs) and rGO tightly surrounded by MnO₂ nanosheets, forming a 3D multilevel porous conductive structure via vacuum freeze‐drying. The sandwich‐like architecture possesses multiple functions as a flexible anode for lithium‐ion batteries. Micrometer‐sized pores among the continuously waved rGO layers could extraordinarily improve ion diffusion. Nano‐sized pores among the MnO₂ nanosheets and CNT/rGO@MnO₂ particles could provide vast accessible active sites and alleviate volume change. The tight connection between MnO₂ and carbon skeleton could facilitate electron transportation and enhance structural stability. Due to the special structure, the rGO‐wrapped CNT/rGO@MnO₂ porous film as an anode shows a high capacity, excellent rate performance, and superior cycling stability (1344.2 mAh g⁻¹ over 630 cycles at 2 A g⁻¹, 608.5 mAh g⁻¹ over 1000 cycles at 7.5 A g⁻¹). Furthermore, the evolutions of microstructure and chemical valence occurring inside the electrode after cycling are investigated to illuminate the structural superiority for energy storage. The excellent electrochemical performance of this freestanding flexible electrode makes it an attractive candidate for practical application in flexible energy storage.

中文翻译：

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用于高性能锂离子电池的柔性石墨烯包裹碳纳米管/ Graphene @ MnO2 3D多层多孔膜

独立式柔性电极的巧妙设计为新兴的可穿戴电子设备中的电源带来了可能性。在这里，还原氧化石墨烯（rGO）将碳纳米管（CNTs）和rGO包裹着MnO ₂纳米片，通过真空冷冻干燥形成3D多层多孔导电结构。类似于三明治的体系结构具有多种功能，可作为锂离子电池的柔性阳极。连续波的rGO层之间的微米级孔隙可以极大地改善离子扩散。MnO ₂纳米片和CNT / rGO @ MnO ₂颗粒之间的纳米孔可以提供广泛的活性位点并减轻体积变化。MnO ₂之间的紧密连接碳骨架可以促进电子传输，增强结构稳定性。由于特殊的结构中，RGO包裹CNT / RGO @的MnO ₂的多孔膜作为阳极示出了高容量，优异的倍率性能和优异的循环稳定性（1344.2毫安克^-1超过630个循环的2 A G ^-1， 608.5毫安克^-1经过1000次循环7.5 A G ^-1）。此外，研究了循环后电极内部发生的微观结构和化学价的演变，以阐明储能的结构优势。这种独立式柔性电极的出色电化学性能使其成为柔性储能中实际应用的有吸引力的候选者。