A green ternary (NaCl/KCl/ZnCl₂) mixed salt-assisted carbonization of spirulina residues was proposed to produce the nitrogen-doped biochar (NBC) with a hierarchical porous structure for the application of supercapacitors. Modifying the ratio of mixed salt to residues and the carbonization temperature allows it to control the specific surface area (SSA) of biochars, the type and content of functional groups, and the graphitization of the carbon skeleton. Here, the eco-friendly mixed salt functioned for a multifunctional purpose by acting as both a pore regulating agent and the reaction medium. The optimal 650–5 sample, produced by a reaction temperature of 650 °C and ratio of 5, exhibited remarkable specific capacitance of 215 F/g and 207 F/g at 0.2 A/g in 1 M H₂SO₄ and 6 M KOH electrolytes, respectively, and the composed symmetrical capacitors showed excellent cycling stability in the four aqueous electrolytes (plus 1 M Na₂SO₄ and 15 mol/kg LiTFSI), with capacitance retention rate all ≥90 % after 10,000 cycles. In the LiTFSI system, the energy density was 25.28 Wh/kg at 375.04 W/kg. Furthermore, experiments using recycled salt confirmed the sustainability of this approach.

提出了一种绿色三元 (NaCl/KCl/ZnCl ₂ ) 混合盐辅助碳化螺旋藻残渣，以生产具有分级多孔结构的氮掺杂生物炭 (NBC)，用于超级电容器应用。改变混盐残渣比和碳化温度，可以控制生物炭的比表面积（SSA）、官能团的类型和含量，以及碳骨架的石墨化。在这里，环保混合盐通过充当孔隙而发挥多功能作用调节剂和反应介质。_{在 650 °C 的反应温度和 5 的反应温度下生成的最佳 650–5 样品在 1 MH 2} SO ₄和 6 M KOH中以 0.2 A/g 表现出 215 F/g 和 207 F/g 的显着比电容电解质和组成的对称电容器在四种水性电解质（加上 1 M Na ₂ SO ₄和 15 mol/kg LiTFSI）中表现出优异的循环稳定性，在 10,000 次循环后电容保持率均≥ 90%。在 LiTFSI 系统中，能量密度在 375.04 W/kg 时为 25.28 Wh/kg。此外，使用回收盐的实验证实了这种方法的可持续性。