Abstract Echinus-like nitrogen-doped carbon with a hierarchical porous structure was synthesized from green larch waste and urea via liquid in situ doping and high-temperature carbonization. Benefitting from a large specific surface area (649 m2 g−1) and hierarchical porous structure, the nitrogen-doped carbon exhibited excellent electrochemical performance for supercapacitors. Remarkably, the echinus-like nitrogen-doped carbon achieved a high specific capacitance of 340 F g−1 at a current density of 1 A g−1 in 6 M KOH electrolyte as well as a good performance rate and stability (with a capacitance retention of 98% after 5000 cycles). This capacitance was almost 1.5 times higher than that of undoped carbon due to the contribution of the pseudocapacitance from the nitrogen doping. Larch sawdust is a promising carbon source for fabricating inexpensive, sustainable and high-performance supercapacitor materials.

中文翻译：

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用于超级电容器应用的具有类海胆结构的落叶松衍生分级氮掺杂碳

摘要 以绿落叶松废料和尿素为原料，通过液态原位掺杂和高温碳化，合成了具有分级多孔结构的类海胆状氮掺杂碳。受益于大比表面积 (649 m2 g-1) 和分级多孔结构，氮掺杂碳对超级电容器表现出优异的电化学性能。值得注意的是，类海胆的氮掺杂碳在 6 M KOH 电解液中在 1 A g-1 的电流密度下实现了 340 F g-1 的高比电容，以及良好的性能速率和稳定性（具有电容保持率） 5000 次循环后为 98%）。由于氮掺杂的赝电容的贡献，该电容几乎是未掺杂碳的电容的 1.5 倍。