Achieving both a high surface area and high heteroatom doping in carbon materials is a major challenge for aqueous-based supercapacitors. Herein, we choose an efficient carbonization–activation pathway to tune the porosity and heteroatom doping level of carbon materials by using jellyfish as the precursor and KOH as the activating agent. Highly Functionalized Jellyfish-Derived Activated Carbons (HFJDACs) possess a high surface area of up to 3300 m² g⁻¹ with nitrogen and oxygen heteroatom doping. Carbon activated at 500 °C displays a capacitance as high as 743 F g⁻¹ and 639 F cm⁻³, while carbons activated at a temperature higher than 500 °C exhibit a favorable capacitance retention of >48.1% at 100 A g⁻¹. These values are among the highest reported in the literature, and therefore these carbon materials can be used as the ideal negative electrode in asymmetric supercapacitors to circumvent the capacitance mismatch between oxide-based positive electrodes and carbon-based negative electrodes. The assembled asymmetric capacitor employing HFJDACs can achieve a high energy density of 43.4 W h kg⁻¹ and an amazing cycle life with capacitance retention of 110% after 20 000 cycles. These results demonstrate that adapting a scalable synthesis strategy for designing carbons with well-developed porosity and high level heteroatom doping is promising for advanced supercapacitors.

中文翻译：

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用于高能非对称超级电容器，以高表面积 提高在原位官能化碳中的伪电容电荷存储†

在碳材料中实现高表面积和高杂原子掺杂是水基超级电容器的主要挑战。在此，我们选择一种有效的碳化活化途径，以水母为前驱体并以KOH为活化剂，以调节碳材料的孔隙率和杂原子掺杂水平。高度功能化的水母衍生活性炭（HFJDAC）具有氮和氧杂原子掺杂的高达3300 m ² g ^-1的高表面积。在500°C下活化的碳表现出的电容高达743 F g ^-1和639 F cm ^-3，而在高于500°C的温度下活化的碳在100 A g ^-1下表现出良好的电容保持率> 48.1％。这些值是文献中报道的最高值，因此，这些碳材料可以用作不对称超级电容器中的理想负极，从而避免了基于氧化物的正极和基于碳的负极之间的电容失配。采用HFJDAC的组装式非对称电容器可实现43.4 W h kg ^-1的高能量密度，并具有惊人的循环寿命，在2万次循环后的电容保持率为110％。这些结果表明，对于先进的超级电容器，采用可扩展的合成策略来设计具有良好孔隙率和高水平杂原子掺杂的碳是有希望的。