Advanced secondary energy storage technologies and key components are crucial to the efficient use of energy resources. Layered antimonene can facilitate ions transport and intercalation. However, the electrochemical mechanism of antimonene is very much a gray area. Herein, we show that the electrolyte ions can make appreciable differences in the energy storage behavior of antimonene. Accordingly, a high value of 599 F g⁻¹ can be obtained by scanning antimonene electrode in 1 _M H₂SO₄ at a rate of 5 mV s⁻¹, which is more than twice the capacitance of those KOH, LiOH and LiCl based electrolyte systems. Systematic investigation including kinetics simulation and extrapolation of surface charge suggests a mixture of surface-controlled and battery-like Faradaic responses of antimonene in acid electrolyte. Electrochemical quartz crystal microbalance (EQCM) combined with first-principles calculation further reveals that hydrated H⁺ is expected to access the “inner” surface sites of antimonene and thus insert or intercalate into the antimonene nanosheets. Notably, an asymmetric supercapacitor composed of antimonene positrode and carbon nanotube negatrode exhibits a wide operating voltage of 1.8 V, a relatively high energy density of 46 Wh Kg⁻¹ at a power density of 450 W Kg⁻¹ and great cycling performance (capacitance retention of up to 112.7% after 5000 cycles, 1.5 A g⁻¹). The paper offers fundamental insights into the influence of electrolyte ions on the electrochemical behavior of 2D Xenes and pushes back the frontiers of designing energy storage systems.

先进的二次储能技术和关键部件对能源资源的高效利用至关重要。层状锑烯可以促进离子传输和嵌入。然而，锑烯的电化学机制在很大程度上是一个灰色地带。在这里，我们表明电解质离子可以对锑烯的储能行为产生明显的影响。_{因此，通过在 1 M} H ₂ SO ₄中以 5 mV s ^-1的速率扫描锑烯电极可以获得 599 F g ^-1的高值，这是那些基于 KOH、LiOH 和 LiCl 的电解质系统的电容的两倍多。包括动力学模拟和表面电荷外推在内的系统研究表明，锑烯在酸性电解质中混合了表面控制和类似电池的法拉第反应。电化学石英晶体微天平 (EQCM) 结合第一性原理计算进一步表明，水合H ⁺有望进入锑烯的“内”表面位点，从而插入或嵌入锑烯纳米片中。值得注意的是，由锑烯正极和碳纳米管负极组成的非对称超级电容器表现出 1.8 V 的宽工作电压，在 450 W Kg 的功率密度下具有 46 Wh Kg ^{-1的相对较高的能量密度-1}和出色的循环性能（5000 次循环后电容保持率高达 112.7%，1.5 A g ^-1）。该论文对电解质离子对 2D Xenes 电化学行为的影响提供了基本见解，并推动了储能系统设计的前沿。