Fiber‐shaped supercapacitors with improved specific capacitance and high rate capability are a promising candidate as power supply for smart textiles. However, the synergistic interaction between conductive filaments and active nanomaterials remains a crucial challenge, especially when hydrothermal or electrochemical deposition is used to produce a core (fiber)–shell (active materials) fibrous structure. On the other hand, although 2D pseudocapacitive materials, e.g., Ti₃C₂T _x (MXene), have demonstrated high volumetric capacitance, high electrical conductivity, and hydrophilic characteristics, MXene‐based electrodes normally suffer from poor rate capability owing to the sheet restacking especially when the loading level is high and solid‐state gel is used as electrolyte. Herein, by hosting MXene nanosheets (Ti₃C₂T _x ) in the corridor of a scrolled carbon nanotube (CNT) scaffold, a MXene/CNT fiber with helical structure is successfully fabricated. These features offer open spaces for rapid ion diffusion and guarantee fast electron transport. The solid‐state supercapacitor based on such hybrid fibers with gel electrolyte coating exhibits a volumetric capacitance of 22.7 F cm⁻³ at 0.1 A cm⁻³ with capacitance retention of 84% at current density of 1.0 A cm⁻³ (19.1 F cm⁻³), improved volumetric energy density of 2.55 mWh cm⁻³ at the power density of 45.9 mW cm⁻³, and excellent mechanical robustness.

中文翻译：

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碳纳米管支架和MXene纳米片之间通过主宾混合产生的固态纤维状超级电容器

具有改善的比电容和高倍率能力的纤维状超级电容器是用作智能纺织品电源的有前途的候选者。然而，导电丝和活性纳米材料之间的协同相互作用仍然是一个关键的挑战，特别是当使用水热或电化学沉积来生产核（纤维）-壳（活性材料）纤维结构时。另一方面，尽管使用2D伪电容材料，例如Ti ₃ C ₂ T _x MXene（MXene）具有高体积电容，高电导率和亲水特性，基于MXene的电极通常会因板料的重新堆叠而导致倍率能力较差，尤其是在装载量较高且使用固态凝胶作为电解质的情况下。在此，通过在滚动碳纳米管（CNT）支架的通道中容纳MXene纳米片（Ti ₃ C ₂ T _x），成功地制造了具有螺旋结构的MXene / CNT纤维。这些功能为快速的离子扩散提供了空间，并确保了快速的电子传输。基于与凝胶电解质涂层，例如混杂纤维的固态超级电容器表现出22.7˚F厘米的体积电容^-3在0.1 A厘米^-3 在1.0 A cm ^-3（19.1 F cm ^-3）的电流密度下具有84％的电容保持率，在45.9 mW cm ^-3的功率密度下改善了2.55 mWh cm ^-3的体积能量密度，并具有出色的机械强度。