碳纳米管桥接rGO/MXene光纤，用于高性能光纤超级电容器

1成果简介

电极框架的定向构造与离子/电子传输路径的对齐对电化学过程至关重大。不过，传统制备策略存在工艺复杂、难以实现规模化生产等瓶颈。本文，浙江大学张玲洁、Ningzhong Bao等在《ADVANCED MATERIALS》期刊发表名为“Flow-Regime-Controlled Fabrication of CNT-Bridged Vertically Aligned rGO/MXene Fibers for High-Performance Fiber Supercapacitors”的论文，研究开发了一种流体驱动湿法纺丝策略，用于制备碳纳米管（CNT）桥接的垂直取向氧化石墨烯（rGO）/MXene纤维（CNT-VA-GMFs）。

通过准确调控流动模式，垂直排列的rGO/MXene纳米片与CNT桥接结构协同构建出：开放多孔通道实现快速离子传输，连续导电网络保障高效电子转移，丰富活性位点提升电荷存储能力。由此制备的CNT-VA-GMF电极在H₂SO₄电解液中展现出优异的离子传输性能、卓越的比电容（740 F g⁻¹）及出色的长期循环稳定性（30,000次循环后容量保持率达98%）。组装的柔性不对称超级电容器在保持强劲机械柔韧性的同时，实现了224Wh kg−1 （在1200W kg−1条件下）的卓越能量密度。

2图文导读

图1、a) Schematic diagram of the flow-driven wet-spinning process for CNT-VA-GMF; b) Front-view and c) cross-sectional micro-CT images of CNT-VA-GMF; d) Front-view and cross-sectional SEM images of CNT-VA-GMF; e) High-magnification SEM and f) TEM images of CNT-VA-GMF; g) EDS elemental mapping of Ti and C in CNT-VA-GMF; h) Structural schematic of CNT-VA-GMF; i) N2 adsorption-desorption isotherms of GMF, VA-GMF, and CNT-VA-GMF.

图2、Flow field variation of GO dispersion with crosslinker ratio of a) 30%, and b) 0%. Part I: Calculated velocity distribution in the expansion channel and in situ polarized light microscopy images of the corresponding region; Part II: SEM images of fibers formed under corresponding condition, and Schematic of GO nanosheet alignment in plug flow versus laminar flow (The detailed trajectories of GO nanosheets were given in Figure S12, Supporting Information). c) Viscosity of GO dispersions with varying crosslinker ratios; d) Calculated shear rate profiles across the expansion channel width.

图3、Electrochemical performance in 3 m H2SO4 electrolyte. a) CV curves of GMF, VA-GMF, CNT-VA-GMF, and VA-GF (vertical graphene fiber) at 10 mV s−1; b) GCD curves of GMF, VA-GMF, CNT-VA-GMF, and VA-GF at 1 A g−1; c) Gravimetric specific capacitance of samples at different scan rates; d) Nyquist plots of GMF, VA-GMF, and CNT-VA-GMF; e) Capacitive contributions of CNT-VA-GMF at different scan rates; f) Gravimetric specific capacitance of vertical fibers with varying MXene content; electrode current density, ion migration trajectory, and electrolyte concentration distribution for g) onion ring structure, h) hetero-vertical structure, and i) CNT-bridged vertical structure; j) Ion migration rate versus normalized fiber depth.

图4、Electrochemical performance of FSC.

3小结

综上所述，通过准确调控膨胀流与塞流之间的流动状态转变，成功制备了基于二维材料的纤维，其具有碳纳米管桥接的垂直取向rGO/MXene结构。原位极化显微镜与计算流体动力学模拟揭示，垂直结构的形成不仅需要膨胀流的取向效应，还需塞流作用以稳定二维纳米片的定向垂直结构。具有该垂直构型的CNT-VA-GMF通过流驱动湿法纺丝技术实现了规模化连续制备。令人鼓舞的是，垂直有序孔结构、MXene/rGO异质界面与CNT桥接骨架的协同作用，使CNT-VA-GMF具备缩短的离子扩散路径、增强的电子导电性及丰富的电化学活性位点。由此，CNT-VA-GMF实现740 F g⁻¹的比电容及超长循环稳定性（在H₂SO₄电解液中经30,000次循环后保持98%容量），验证其卓越的电荷存储能力与可逆离子吸附/脱附动力学特性。此外，组装的FSC展现出224 Wh kg-1的能量密度、延长循环寿命（20,000次循环后保持率达98%）及优异柔韧性，成功驱动LED灯、电风扇和玩具船等应用实证。

文献：

https://doi.org/10.1002/adma.202516561

来源：材料分析与应用