Porous carbon nanotubes with unique structure is an ideal electrode material for supercapacitors. However, the synthesis of porous carbon nanotubes requires expensive catalysts such as heavy metals or heavy metal salts, which limits their wider application. To solve the problem, a one-step high-temperature potassium chloride-catalyzed strategy is proposed to directly grow porous carbon nanotubes. Magnesium reacts with carbon dioxide to form carbon as the carbon source and magnesium oxide that can form porosity of carbon nanotubes. Low-cost and recyclable potassium chloride can replaced expensive heavy metals or heavy metal salts to catalyze the growth of porous carbon nanotubes. The obtained porous carbon nanotube (CC-KCl-700) show great advantages in structure and delivers excellent electrochemical properties and its specific capacitance reaches up to 334.4 F g⁻¹. After 10,000 cycles at 10 A g⁻¹, the capacitance of the CC-KCl-700 still reaches to 230 F g⁻¹. Beside, the assembled symmetric supercapacitor with a high energy density and great rate performance can successfully provide energy for devices.

具有独特结构的多孔碳纳米管是超级电容器的理想电极材料。然而，多孔碳纳米管的合成需要昂贵的催化剂，如重金属或重金属盐，这限制了其更广泛的应用。为了解决这个问题，提出了一步高温氯化钾催化的策略直接生长多孔碳纳米管。镁与二氧化碳反应生成作为碳源的碳和可形成碳纳米管孔隙的氧化镁。低成本且可回收的氯化钾可以替代昂贵的重金属或重金属盐来催化多孔碳纳米管的生长。^-1。在 10 A g ^-1下循环 10,000 次后，CC-KCl-700 的电容仍然达到 230 F g ^-1。此外，组装后的对称超级电容器具有高能量密度和良好的倍率性能，可以成功地为器件提供能量。