Abstract Polyimides have been used as the precursor of carbon materials. Thermal rearrangement polymers with porous structure can be prepared by thermal treatment of hydroxyl-containing polyimides in the solid state. Herein, hydroxyl-containing polyimides with hierarchical microspheres were firstly prepared by solvothermal method. After thermal rearrangement at 450 °C and further carbonization, the hierarchical porous nitrogen-doped carbon microspheres were obtained, which showed good electrochemical characteristics. The effects of the concentration of polymer solution, thermal rearrangement time and final carbonization temperature on the structure and properties of final carbon materials were investigated. The hierarchical porous carbon materials were tested as an electrode for supercapacitors, and HPI-45–2-800 with high specific surface area of 877 m2 g−1 exhibited excellent electrochemical properties. The specific capacitance of HPI-45–2-800 was 211.3 F g−1 at the current density of 0.5 A g−1. When the current density was increased to 10 A g−1, the retention rate of specific capacitance was as high as 55%. After 10,000 cycles of charging and discharging, the specific capacitance of HPI-45–2-800 electrode was still retained 99.94% of the initial capacitance, showing excellent long-term charge–discharge cycling stability. The hierarchical porous nitrogen-doped carbon microspheres after thermal rearrangement are expected to be high performance electrode materials for supercapacitors.

中文翻译：

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热重排后的分级多孔氮掺杂碳微球作为超级电容器的高性能电极材料

摘要 聚酰亚胺已被用作碳材料的前驱体。具有多孔结构的热重排聚合物可以通过对固态的含羟基聚酰亚胺进行热处理来制备。在此，首次采用溶剂热法制备了具有分级微球的含羟基聚酰亚胺。在450℃热重排并进一步碳化后，得到分级多孔氮掺杂碳微球，具有良好的电化学特性。研究了聚合物溶液浓度、热重排时间和最终碳化温度对最终碳材料结构和性能的影响。分级多孔碳材料作为超级电容器的电极进行了测试，和具有 877 m2 g-1 高比表面积的 HPI-45-2-800 表现出优异的电化学性能。HPI-45-2-800 的比电容在 0.5 A g-1 的电流密度下为 211.3 F g-1。当电流密度增加到 10 A g-1 时，比电容保持率高达 55%。经过10,000次充放电循环后，HPI-45-2-800电极的比电容仍保持初始电容的99.94%，表现出优异的长期充放电循环稳定性。热重排后的分级多孔掺氮碳微球有望成为超级电容器的高性能电极材料。当电流密度增加到 10 A g-1 时，比电容保持率高达 55%。经过10,000次充放电循环后，HPI-45-2-800电极的比电容仍保持初始电容的99.94%，表现出优异的长期充放电循环稳定性。热重排后的分级多孔掺氮碳微球有望成为超级电容器的高性能电极材料。当电流密度增加到 10 A g-1 时，比电容保持率高达 55%。经过10,000次充放电循环后，HPI-45-2-800电极的比电容仍保持初始电容的99.94%，表现出优异的长期充放电循环稳定性。热重排后的分级多孔掺氮碳微球有望成为超级电容器的高性能电极材料。