Flexible electrodes with robust mechanical properties and high electrochemical performance are of significance for the practical implementation of flexible batteries. Here we demonstrate a general and straightforward co-assembly approach to prepare flexible electrodes, where electrochemically exfoliated graphene (EG) is exploited as the film former/conducting matrix and different binary metal oxides (Li₄Ti₅O₁₂, LiCoO₂, Li₂MnO₄, LiFePO₄) are incorporated. The resultant EG–metal oxide hybrids exhibit a unique layer-interlocked structure, where the metal oxide is conformably wrapped by the highly flexible graphene. Due to numerous contact interphases generated between EG and the intercalated material, the hybrid films show high flexibility and can endure rolling, bending, folding and even twisting. When serving as the anode for Li-ion batteries, the freestanding EG–Li₄Ti₅O₁₂ hybrid presents a characteristic flat discharge plateau at 1.55 V (vs. Li/Li⁺), indicating transformation of Li₄Ti₅O₁₂ to Li₇Ti₅O₁₂. Small polarization, high rate capability and excellent cycling stability against mechanical bending are also demonstrated for the prepared EG–Li₄Ti₅O₁₂ hybrid. Finally, full cells composed of EG–Li₄Ti₅O₁₂ and EG–LiFePO₄ hybrids show impressive cycling (98% capacity retention after 100 cycles at 1C) and rate performance (84% capacity retained at 2.5C). The straightforward co-assembly approach based on EG can be extended to other two-dimensional layered materials for constructing highly efficient flexible energy storage devices.

中文翻译：

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方便地组装层互锁的石墨烯异质结构作为锂离子电池的柔性电极

具有坚固的机械性能和高电化学性能的柔性电极对于柔性电池的实际实施具有重要意义。在这里，我们演示了一种通用而直接的组装方法来制备柔性电极，其中电化学剥落的石墨烯（EG）被用作成膜剂/导电基质和不同的二元金属氧化物（Li ₄ Ti ₅ O ₁₂，LiCoO ₂，Li ₂ MnO ₄，LiFePO ₄）。所得的EG-金属氧化物杂化物表现出独特的层互锁结构，其中金属氧化物被高柔性石墨烯保形包裹。由于在EG和插层材料之间产生大量接触界面，因此杂化膜显示出很高的柔韧性，并且可以承受滚动，弯曲，折叠甚至扭曲。当用作锂离子电池的阳极时，独立式EG–Li ₄ Ti ₅ O ₁₂混合动力电池在1.55 V（相对于Li / Li ⁺）下表现出典型的平坦放电平稳期，表明Li ₄ Ti ₅ O ₁₂转变为锂₇钛₅ O₁₂。制备的EG-Li ₄ Ti ₅ O ₁₂杂化材料还显示出小极化，高倍率性能和出色的抗机械弯曲循环稳定性。最后，由EG–Li ₄ Ti ₅ O ₁₂和EG–LiFePO ₄杂化物组成的全电池显示出令人印象深刻的循环性能（在1C下100次循环后，容量保持率达到98％）和速率性能（在2.5C下，容量保持率达到84％）。基于EG的直接组装方法可以扩展到其他二维分层材料，以构造高效的柔性能量存储设备。