Condensed Matter Science and Technology Institute, Department of Physics, Harbin Institute of Technology, Harbin 150001, People's Republic of China and Key Laboratory for Photonic and Electronic Bandgap Materials, Ministry of Education, School of Physics and Electronic Engineering, Harbin Normal University, Harbin 150025, People's Republic of China.
Department of Chemistry and Chemical Biology, Cornell University, Ithaca, USA.
Dalton Trans. 2019 Feb 7;48(5):1747-1756. doi: 10.1039/c8dt04374d. Epub 2019 Jan 14.
MXenes are two-dimensional transition metal carbides/nitrides, and they have shown exciting application prospects for electrochemical energy storage in the future owing to their hydrophilicity, metallic conductivity and surface redox reactions, which are crucial for high-capacitance and high-rate electrode materials. However, the strong tendency of adjacent MXene flakes to aggregate or self-restack under the van der Waals force limits the electrochemical performance of MXene-based electrodes for practical applications. In this study, we developed a simple and effective method to prepare TiCT/PEDOT:PSS hybrid films via filtering the TiCT/Clevios PH1000 compound inks, followed by HSO treatment. HSO treatment could remove part of the insulating PSS from the TiCT/PEDOT:PSS hybrid film, resulting in significant conductivity enhancement of the composite. Furthermore, the conductive PEDOT not only acted as a pillar between TiCT sheets to expose more electroactive surfaces and reduce ion diffusion pathways but also played a role as a conductive bridge to form multidimensional electronic transport channels for accelerating the electrochemical reaction process. As a result, the as-prepared HSO-treated TiCT/PEDOT:PSS (TiCT/P-100-H) hybrid film exhibited 4.5-fold increase in the specific surface area and high volumetric capacitance of 1065 F cm at 2 mV s with superior rate performance in 1 M HSO electrolyte. Especially, we assembled an asymmetric supercapacitor (ASC) with excellent flexibility based on a TiCT/P-100-H hybrid negative electrode and rGO film positive electrode, which delivered high energy density of 23 mW h cm and high power density of 7659 mW cm. Moreover, a simple luminous band was designed and powered by our two ASCs in series. The outstanding volumetric electrochemical performance and energy density of the ASC based on the flexible TiCT/P-100-H hybrid film electrode demonstrated its promising potential as a strong power source for small portable and wearable electronic devices.
MXenes 是二维过渡金属碳化物/氮化物，由于其亲水性、金属导电性和表面氧化还原反应，在未来的电化学储能中具有令人兴奋的应用前景，这些特性对于高容量和高倍率电极材料至关重要。然而，由于范德华力的作用，相邻 MXene 薄片倾向于聚集或自堆叠，这限制了 MXene 基电极在实际应用中的电化学性能。在本研究中，我们开发了一种简单有效的方法，通过过滤 TiCT/Clevios PH1000 复合油墨来制备 TiCT/PEDOT:PSS 混合薄膜，然后进行 HSO 处理。HSO 处理可以从 TiCT/PEDOT:PSS 复合薄膜中去除部分绝缘的 PSS，从而显著提高复合材料的导电性。此外，导电的 PEDOT 不仅作为 TiCT 片之间的支柱，暴露出更多的电活性表面并减小离子扩散路径，而且还作为导电桥形成多维电子传输通道，从而加速电化学反应过程。结果，所制备的 HSO 处理的 TiCT/PEDOT:PSS（TiCT/P-100-H）混合薄膜的比表面积增加了 4.5 倍，在 2 mV s 下的体积电容高达 1065 F cm，具有优异的倍率性能在 1 M HSO 电解质中。特别是，我们基于 TiCT/P-100-H 混合负极和 rGO 薄膜正极组装了具有出色柔韧性的不对称超级电容器（ASC），其能量密度高达 23 mW h cm，功率密度高达 7659 mW cm。此外，我们设计了一个简单的发光带，并由我们的两个 ASC 串联供电。基于柔性 TiCT/P-100-H 混合薄膜电极的 ASC 具有出色的体积电化学性能和能量密度，展示了其作为小型便携式和可穿戴电子设备的强大电源的巨大潜力。
