Ce³⁺离子修饰Ti₃C₂T_X二维材料及其超级电容器性能研究

Ce³⁺-Modified Ti₃C₂Tₓ 2D Material for Supercapacitors

摘要: 二维Ti₃C₂T_x有着独特的二维结构、高导电性、亲水性、可调层间结构与丰富的活性位点，能够实现高比电容，有着优异的倍率性能与循环稳定性。然而，二维纳米片层易发生堆叠，限制电容性能的发挥，在强酸性电解液中表面官能团易发生氧化，结构易坍塌，影响其化学性能。本文通过Ce³⁺离子嵌入对Ti₃C₂T_x表面进行界面工程调控，提高其倍率性能。采用碱处理和离子交换实现Ce³⁺离子嵌入，使得Ti₃C₂T_x电极在电流密度1 A·g⁻¹时显示出322 F·g⁻¹的高比电容，在10 A·g⁻¹电流密度下经过30,000次恒流充放电循环后仍保持优异的电化学稳定性，证明Ce³⁺修饰是提升Ti₃C₂Tₓ二维材料超级电容器负极性能的有效手段。

Abstract: Two-dimensional Ti₃C₂Tₓ possesses a unique 2D structure, high electrical conductivity, good hydrophilicity, tunable interlayer structure, and abundant active sites, enabling high specific capacitance as well as excellent rate capability and cycling stability. However, the 2D nanosheets are prone to restacking, which limits the capacitive performance. Moreover, the surface functional groups are easily oxidized and the structure tends to collapse in strongly acidic electrolytes, thus impairing its electrochemical properties. In this work, interface engineering of Ti₃C₂Tₓ was carried out via Ce³⁺ ion intercalation to improve its rate capability. Alkali treatment and ion exchange were employed to achieve Ce³⁺ intercalation. The resulting Ti₃C₂Tₓ electrode delivered a high specific capacitance of 322 F·g⁻¹ at a current density of 1 A·g⁻¹ and retained outstanding electrochemical stability after 30,000 galvanostatic charge-discharge cycles at 10 A·g⁻¹. These results demonstrate that Ce³⁺ modification is an effective strategy to enhance the performance of Ti₃C₂Tₓ as an anode material for 2D material-based supercapacitors.