Two-dimensional (2D) Ti₃C₂T_x MXene has shown great potential in the energy storage field, and its performance strongly depends on the intercalation of cations. Therefore, engineering its interlayer ion channels is the key to enhance the electrochemical performance of Ti₃C₂T_x, but it is challenging due to the restacking nature of 2D materials. Herein, an original strategy for in situ introduction of large-size and electrostatic −SO₄ termination is developed to engineer Ti₃C₂T_x MXene interlayer channels. The chemical binding and steric effect of −SO₄ termination ensure a stable and expanded interlayer ion channel. The electrostatic effect of −SO₄ benefits electrolyte ion infiltration. Consequently, the capacitance of Ti₃C₂T_x is increased by approximately 66 and 143% compared to those synthesized by common methods. The Ti₃C₂T_x electrode exhibits a high areal capacitance of 1399.0 mF cm^–2 at 1 mV s^–1, excellent rate capability, and ultralong cycle life without capacitance loss after 17,200 cycles. The all-solid-state supercapacitor (ASSS) based on the Ti₃C₂T_x delivers an ultrahigh areal capacitance of 391.5 mF cm^–2, which reaches the state-of-the-art level. Moreover, the ASSS shows excellent flexibility and wearable potential. The established strategy blazes a new trail to improve the capacitance performance of MXenes.

中文翻译：

---

柔性MXene电极的超高面积电容：端接的静电和立体效应

二维（2D）Ti ₃ C ₂ T _x MXene在储能领域显示出巨大潜力，其性能在很大程度上取决于阳离子的嵌入。因此，对其层间离子通道进行工程设计是增强Ti ₃ C ₂ T _x电化学性能的关键，但由于2D材料的重堆积特性，这具有挑战性。本文中，开发了一种原位引入大尺寸静电-SO ₄端接的原始策略来设计Ti ₃ C ₂ T _x MXene中间层通道。-SO ₄的化学结合和空间效应端接可确保稳定且扩展的层间离子通道。-SO ₄的静电作用有利于电解质离子的渗透。因此，与通过常规方法合成的电容相比，Ti ₃ C ₂ T _x的电容增加了大约66％和143％。Ti ₃ C ₂ T _x电极在1 mV s ^-1时具有1399.0 mF cm ^-2的高面积电容，出色的倍率能力以及超长的循环寿命，在经过17,200次循环后无电容损耗。基于Ti ₃ C ₂ T _x的全固态超级电容器（ASSS）提供391.5 mF cm ^–2的超高面积电容，达到了最新水平。此外，ASSS还具有出色的柔韧性和可穿戴性。既定的策略开创了改善MXene电容性能的新途径。