In spite of the excellent electrical and electrochemical properties, two-dimensional transition metal carbide (MXene) is often limited by the high stiffness for the direct implementation in next-generation stretchable and wearable energy storage devices. The improved deformability has been achieved in ultrathin composite electrodes utilizing additives that substantially reduce the specific capacitance. Here, we demonstrate an ultrastretchable and high-performing supercapacitor based on MXene electrodes with crumpled textures. After screening on the thickness, the crumpled MXene film of ∼3 μm in thickness is identified as the optimal choice to mitigate the crack formations under large and repetitive mechanical strains. The as-prepared symmetric supercapacitor, therefore, demonstrates a high specific capacitance of ∼470 mF cm^–2, ultrahigh stretchability up to 800% area strain, and >90% retention of the initial capacitance after 1000 stretch–relaxation cycles. The developments offer an attractive avenue to design stretchable electrodes based on various two-dimensional nanomaterials and their composites.

中文翻译：

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用于超拉伸和高面积电容超级电容器的皱褶 MXene 电极

尽管具有优异的电学和电化学性能，但二维过渡金属碳化物 (MXene) 通常受到高刚度的限制，无法直接用于下一代可拉伸和可穿戴储能设备。使用可显着降低比电容的添加剂在超薄复合电极中实现了改进的变形能力。在这里，我们展示了一种基于具有皱褶纹理的 MXene 电极的超拉伸和高性能超级电容器。在对厚度进行筛选后，厚度约为 3 μm 的皱巴巴的 MXene 薄膜被确定为在大且重复的机械应变下减轻裂纹形成的最佳选择。因此，所制备的对称超级电容器具有~470 mF cm的高比电容^–2，高达 800% 的区域应变的超高拉伸性，并且在 1000 次拉伸-松弛循环后初始电容保持率 >90%。这些发展为设计基于各种二维纳米材料及其复合材料的可拉伸电极提供了一条有吸引力的途径。