3D construction or pore-forming of carbon nanosheets brings the materials exceptional energy storage performance. However, these strategies involve complicated procedures and challenging conditions. Herein, based on the structural regulation of a MAX phase, a facile method was proposed to prepare MAX-derived carbon (MDC) with dual tunability of dimension and pore structure via molten salt electrochemical etching-gaseous sulfur delamination coupling. Polyhedral structure TiSC and highly oriented structure TiSC were transformed into 3D Mesopore carbon nanoshells (3D Meso-CNSL) and 2D Mesopore carbon nanosheets (2D Meso-CNST) in one step. By matching the decomposition voltage of TiCl with that of PS-TiSC, Cl gas generated in situ was employed to enhance the porosity of the 3D Meso-CNSL, resulting in the formation of 3D meso/macro-porous carbon nanoshells (3D Meso/Macro-CNSL) with doubled pore volume (1.45 cm g) and specific surface area (649.97 m g). The 3D Meso/Macro-CNSL exhibits excellent capacity performance and cycle stability under high current density. The capacities are 674.8 mAh g and 501.5 mAh g after 1000 cycles at 5 A g and 10 A g, respectively. It is the first report on the direct delamination of MAX phases into 3D nanomaterials, presenting a new pathway for the precise regulation of the nanostructure of the MDCs.

中文翻译：

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通过熔盐电解揭示 MAX 衍生碳的尺寸和孔隙结构的双重可调性

碳纳米片的 3D 结构或孔隙形成为材料带来了卓越的储能性能。然而，这些策略涉及复杂的程序和具有挑战性的条件。在此，基于MAX相的结构调控，提出了一种通过熔盐电化学蚀刻-气态硫分层耦合制备具有尺寸和孔结构双重可调性的MAX衍生碳（MDC）的简便方法。多面体结构TiSC和高度取向结构TiSC一步转化为3D介孔碳纳米壳（3D Meso-CNSL）和2D介孔碳纳米片（2D Meso-CNST）。通过将 TiCl 的分解电压与 PS-TiSC 的分解电压相匹配，利用原位产生的 Cl 气体来增强 3D Meso-CNSL 的孔隙率，从而形成 3D 介观/大孔碳纳米壳（3D Meso/Macro） -CNSL）具有双倍的孔体积（1.45 cm g）和比表面积（649.97 m g）。 3D Meso/Macro-CNSL在高电流密度下表现出优异的容量性能和循环稳定性。在5 A g和10 A g下循环1000次后，容量分别为674.8 mAh g和501.5 mAh g。这是第一份关于 MAX 相直接分层成 3D 纳米材料的报告，为精确调控 MDC 纳米结构提供了一条新途径。