Transition metal carbon/nitrogen compound (MXene) materials are considered promising candidate materials for lithium-ion storage. Although various porous MXene electrodes have been constructed, the effect of nano curvature on the lithium storage performance of MXene has been rarely studied. This article reports the preparation of porous MXene materials with varying surface nano curvatures using melamine formaldehyde (MF) spheres of different diameters (150, 300, 800, 1400, 2000 nm) by calcination to remove templates. Surprisingly, when the MXene hollow spheres have the maximum nano curvature (template size of 300 nm), the interface electric field strength is much higher than others, providing the highest specific capacity of 414 mAh g⁻¹ at 1 A g⁻¹. Due to the formation of a strong local electrostatic field near the MXene hollow sphere anode, a nearly heterojunction structure is formed between the electrode surface and the electrolyte. Under the influence of the space charge area and the built-in electric field, the ion diffusion rate and electron transfer rate are improved, which helps to overcome the unbalanced electrode dynamics in lithium ion capacitors (LICs) and achieve higher power performance. The device exhibits a maximum energy density of 81.3 Wh kg⁻¹ and a maximum power density of 7200 W kg⁻¹. This work demonstrates the potential of MXene two-dimensional materials in energy storage applications and provides insightful guidance for designing porous electrodes for LICs anodes.

中文翻译：

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设计与研究具有不同纳米曲率的 N 掺杂 3D 空心球 MXene 作为高性能锂离子电容器的阳极


过渡金属碳/氮化合物 （MXene） 材料被认为是有前途的锂离子存储候选材料。尽管已经构建了各种多孔 MXene 电极，但纳米曲率对 MXene 储锂性能的影响却鲜有研究。本文报道了使用不同直径 （150、300、800、1400、2000 nm） 的三聚氰胺甲醛 （MF） 球通过煅烧去除模板制备具有不同表面纳米曲率的多孔 MXene 材料。令人惊讶的是，当 MXene 空心球体具有最大的纳米曲率（模板尺寸为 300 nm）时，界面电场强度远高于其他球体，在 1 A ^g-1 下提供 414 mAh ^g-1 的最高比容量。由于在 MXene 空心球阳极附近形成强局部静电场，因此在电极表面和电解质之间形成了近异质结结构。在空间电荷区和内置电场的影响下，离子扩散速率和电子转移速率得到提高，有助于克服锂离子电容器 （LIC） 中不平衡的电极动力学，实现更高的功率性能。该设备的最大能量密度为 81.3 Wh ^kg-1，最大功率密度为 7200 W ^kg-1。这项工作展示了 MXene 二维材料在储能应用中的潜力，并为设计 LICs 阳极的多孔电极提供了有见地的指导。