MXenes, a young family of 2D transition metal carbides/nitrides, show great potential in electrochemical energy storage applications. Herein, a high performance ultrathin flexible solid‐state supercapacitor is demonstrated based on a Mo_1.33C MXene with vacancy ordering in an aligned layer structure MXene/poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonic acid) (PEDOT:PSS) composite film posttreated with concentrated H₂SO₄. The flexible solid‐state supercapacitor delivers a maximum capacitance of 568 F cm⁻³, an ultrahigh energy density of 33.2 mWh cm⁻³ and a power density of 19 470 mW cm⁻³. The Mo_1.33C MXene/PEDOT:PSS composite film shows a reduction in resistance upon H₂SO₄ treatment, a higher capacitance (1310 F cm⁻³) and improved rate capabilities than both pristine Mo_1.33C MXene and the nontreated Mo_1.33C/PEDOT:PSS composite films. The enhanced capacitance and stability are attributed to the synergistic effect of increased interlayer spacing between Mo_1.33C MXene layers due to insertion of conductive PEDOT, and surface redox processes of the PEDOT and the MXene.

中文翻译：

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基于可解决方案的Mo1.33C MXene和PEDOT：PSS的高性能超薄柔性固态超级电容器

MXenes是2D过渡金属碳化物/氮化物的年轻家族，在电化学储能应用中显示出巨大潜力。在本文中，基于Mo _1.33 C MXene的高性能超薄柔性固态超级电容器得到了证明，该MXene在排列的层结构MXene /聚（3,4-乙烯二氧噻吩）：聚（苯乙烯磺酸）（PEDOT：PSS）复合材料中具有空位有序用浓H ₂ SO _{4后处理的}薄膜。柔性固态超级电容器可提供568 F cm ^-3的最大电容，33.2 mWh cm ^-3的超高能量密度和19470 mW cm ^-3的功率密度。莫_1.33与原始Mo _1.33 C MXene和未经处理的Mo _1.33 C / PEDOT相比，C MXene / PEDOT：PSS复合膜在H ₂ SO ₄处理后显示出电阻降低，更高的电容（1310 F cm ^-3）和更高的倍率能力： PSS复合膜。增强的电容和稳定性归因于由于导电PEDOT的插入而导致的Mo _1.33 C MXene层之间的层间间距增加以及PEDOT和MXene的表面氧化还原过程的协同效应。