Feng Shuxuan, Wang Xin, Wang Menglu, Bai Chong, Cao Shitai, Kong Desheng
College of Engineering and Applied Sciences, State Key Laboratory of Analytical Chemistry for Life Science, and Jiangsu Key Laboratory of Artificial Functional Materials, Nanjing University, Nanjing 210046, China.
Nano Lett. 2021 Sep 22;21(18):7561-7568. doi: 10.1021/acs.nanolett.1c02071. Epub 2021 Sep 8.
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, 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.
尽管二维过渡金属碳化物（MXene）具有优异的电学和电化学性能，但在直接应用于下一代可拉伸和可穿戴储能设备时，其高刚度常常限制了它的使用。利用添加剂的超薄复合电极虽实现了可变形性的改善，但大幅降低了比电容。在此，我们展示了一种基于具有褶皱纹理的MXene电极的超可拉伸且高性能的超级电容器。经过对厚度的筛选，确定厚度约为3μm的褶皱MXene薄膜是减轻在大的重复机械应变下裂纹形成的最佳选择。因此，所制备的对称超级电容器表现出约470 mF/cm的高比电容、高达800%面积应变的超高拉伸性以及在1000次拉伸-松弛循环后初始电容保留率>90%。这些进展为基于各种二维纳米材料及其复合材料设计可拉伸电极提供了一条有吸引力的途径。
