TiO2修饰MXene-PVDF复合碳纳米纤维毡，用柔性透气微型超级电容器

摘要：可穿戴电子设备对柔性储能解决方案的需求促使人们探索为微型超级电容器（μSC）量身定制的创新电极结构。本文，韩国光云大学Jae Yeong Park等研究人员在《Carbon》期刊发表名为“TiO2 nanoparticles-decorated MXene-P

1成果简介

可穿戴电子设备对柔性储能解决方案的需求促使人们探索为微型超级电容器（μSC）量身定制的创新电极结构。本文，韩国光云大学Jae Yeong Park等研究人员在《Carbon》期刊发表名为“TiO2 nanoparticles-decorated MXene-PVDF composite carbon nanofibrous mats-based free-standing electrodes for flexible and breathable microsupercapacitors”的论文，研究提出了一种创新方法，利用激光诱导的MXene-PVDF纳米纤维基质结构来制造独立的纳米复合碳电极，用于柔性透气微超级电容器应用。

在聚合物纳米纤维基质中集成 MXene 混合物、激光碳化以及随后的氧气（O2）-等离子体处理可提供多种协同特性组合，包括高导电性、润湿性、机械柔韧性和更大的电荷存储表面积。此外，激光诱导碳化工艺还能通过光化学合成的球形金属氧化物（TiO2）纳米颗粒，均匀地附着在聚偏二氟乙烯（PVDF）为骨架的碳化纳米纤维（CNF）上，从而精确控制电极的形态和成分，这些纳米颗粒可用作μSC的活性电极材料。基于纳米聚偏二氟乙烯（PVDF）@MXene CNF-O 的杂化μSC 具有高机械柔韧性、耐久性、优异的能量密度（9.81×10-3mWh cm-2）和优异的电容（约79.2mF cm-2 @ 10 mV s-1），10000次循环后电容保持率达 97%。这项研究标志着柔性μSC的开发取得了重大进展，有望彻底改变可穿戴电子设备和生物识别传感技术，从而提高人类的福祉和生活质量。

2图文导读

图1. (A) Schematic illustration of the electrospun Ti3C3Tx@PVDF-based nanofibers mat (NFM). (B) Laser-induced carbonization of the NFM, thermally grown TiO2 nanoparticles and microsupercapacitor fabrication procedure. (C) FESEM (zoom view) image of the laser-induced TiO2 nanoparticles grown on 3D porous carbonized MXene@PVDF-based nanofiber Mat (NFM). (D) FESEM image of single layer MXene (Ti3C2Tx) flakes. (E) UV-vis of diluted Ti3C2Tx solution.

图2. (A) Wide-angle PXRD patterns of as-synthesized MAX-phase, multilayer MXene (ML), delaminated MXene (del-MXene), (B) PVDF-CNF, PVDF@MXene-CNF, and PVDF@MXene-CNF-O. (C) XPS survey spectra of PVDF-CNF, PVDF@MXene-CNF, and PVDF@MXene-CNF-O. Deconvoluted peaks of (D) O 1s, (E) C 1s, and (F) Ti 2p for PVDF-CNFM, PVDF@MXene CNF, and PVDF@MXene CNF-O. (G) Raman survey spectrum of bare PVDF NF, PVDF CNF, MXene@PVDF NF, PVDF@MXene CNF, and PVDF@MXene CNF-O.

图3. Morphological characterization of the MXene and MXene@PVDF-derived carbonized nanofiber (CNF). (A-C) FESEM images of MAX-phase, multilayer MXene after HF etching, and MXene after delamination process, respectively. (D) FESEM image of bare-PVDF electrospun nanofiber. (E) FESEM image of MXene@PVDF-based electrospun nanofiber. (F) HRTEM image of MXene@PVDF-based electrospun nanofiber showing the MXene particle trace inside the nanofiber. (G) FESEM image of the laser-induced carbonized bare PVDF-based nanofiber. (H) FESEM image of the laser-induced carbonized MXene@PVDF-based nanofibers indicating thermally oxidized TiO2 nanoparticles. (I) Elemental mapping images for the LICNF revealing the presence of Ti, O, and C. (J) Photographs of the Polyimide (PI) film and porous PVDF@MXene CNF-O nanofibrous film (K) at initial state, and (L) after 1 h.

图4. Individual electrode electrochemical performances in an aqueous electrolyte containing 1 M H2SO4. (A) CV profiles of the PVDF@MXene CNF-O at various scan rates, a quasirectangular CV shape suggests effective double-layer development with corresponding (B) areal and volumetric capacitance as a function of scan rate. (C) GCD profile comparison at 2.6 mA cm-2 current density for PVDF CNF, PVDF@MXene CNF, and PVDF@MXene CNF-O. (D) GCD of PVDF@MXene CNF-O with different current densities. (E) areal and volumetric capacitance as a function of current density for the PVDF@MXene CNF-O electrode. (F) EIS using fitted curves of the PVDF@MXene CNF-O electrodes using 1M aqueous H2SO4 solution as the electrolyte.

图5. The electrochemical performance of single μSC with PVA-H2SO4 solid electrolyte. (A) PVDF CNF, PVDF@MXene CNF, and PVDF@MXene CNF-O-based μSC comparative CV curves at a scan rate of 10 mV s-1. (B) CV profiles of PVDF@MXene CNF-O at different scan rates and (C) corresponding areal and volumetric capacitance as a function of scan rate. (D) Comparative GCD profiles of PVDF CNF, PVDF@MXene CNF, and PVDF@MXene CNF-O-based μSC at a current density of 0.125 mA cm-2. (E) GCD profiles of PVDF@MXene CNF-O at different current densities and (F) corresponding areal and volumetric capacitance as a function of current densities. (G) Cyclic stability of PVDF@MXene CNF-O. (H) The device retains ∼95% of its initial capacitance after 10,000 charge/discharge cycles. (I) CV profiles of PVDF@MXene CNF-O under different bending conditions.

图6. (A) Schematic of the series and parallel combinations of three μSC electrodes. CV curves at 10 mVs-1 and GCD profiles at 0.5 mA cm-2 of PVDF@MXene CNF-O μSC devices connected in (B, C) series and (D, E) parallel. (F) Photograph of commercial red, LEDs powered by μSC devices connected in series.

3小结

通过细致的合成、表征和性能评估，本研究证明了将低成本碳前驱体（PVDF）和Ti3C2Tx MXene 融合在柔性微型超级电容器中的创新电极结构的可行性。将 MXene 混合物集成到聚合物纳米纤维基质中可提供柔性微型超级电容器所必需的各种性能的协同组合，包括高导电性、机械柔韧性和更大的电荷存储表面积。激光诱导制造方法可对电极形态和组成进行精确控制，从而创建出性能和耐用性最优化的定制架构。对所制备电极进行的电化学表征显示，这些电极具有优异的电容、快速充放电动力学和出色的循环稳定性，证明了它们适用于生物电位信号监测应用。微型超级电容器平台的灵活性和可变形性确保了其与可穿戴基底的无缝集成，从而实现了对生理参数的舒适而不突兀的实时监测。从本质上讲，这项研究的成果凸显了先进电极架构在塑造未来可穿戴电子设备和生物识别传感技术方面的变革潜力。通过推动材料科学和设备工程学的发展，激光诱导MXene嵌入聚合物纳米纤维基质电极为提高人类福祉和生活质量的创新解决方案铺平了道路。

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