Mu Qingnan, Liu Chang, Guo Yao, Wang Kun, Gao Zhijie, Du Yuhan, Cao Changqing, Duan Peigao, Kapusta Krzysztof
Shaanxi Key Laboratory of Energy Chemical Process Intensification, School of Chemical Engineering and Technology, Xi'an Jiaotong University, Xi'an 710049, China.
Institute for Advanced Technology, Shandong University, Jinan 250100, China.
Materials (Basel). 2024 Aug 10;17(16):3984. doi: 10.3390/ma17163984.
To address the problem of the low nitrogen (N) content of carbon materials prepared through the direct carbonization of food waste, soybean meal and egg whites with high N contents were selected to carry out carbonization experiments on food waste. At 220 °C, the effects of hydrothermal carbonization and microwave carbonization on the properties of supercapacitor electrode materials were investigated. The results show that food waste doped with soybean meal and egg whites could achieve good N doping. At a current density of 1 A·g, the specific capacitance of the doped carbon prepared by hydrothermal doping is as high as 220.00 F·g, which is much greater than that of the raw material prepared through the hydrothermal carbonization of food waste alone, indicating that the hydrothermal carbonization reactions of soybean meal, egg white, and food waste promote the electrochemical properties of the prepared carbon materials well. However, when a variety of raw materials are mixed for pyrolysis carbonization, different raw materials cannot be fully mixed in the pyrolysis process, and under the etching action of potassium hydroxide, severe local etching and local nonetching occur, resulting in a severe increase in the pore size distribution and deterioration of the electrochemical performance of the prepared carbon materials. At a current density of 1 A·g, the specific capacitance of these prepared carbon materials is 157.70 F·g, whereas it is only 62.00 F·g at a high current density of 20 A·g. Therefore, this study suggests that the hydrothermal carbonization process is superior to the microwave pyrolysis carbonization process for preparing supercapacitor electrode materials with multiple samples doped with each other.
为了解决通过食物垃圾直接碳化制备的碳材料氮（N）含量低的问题，选择了含氮量高的豆粕和蛋清对食物垃圾进行碳化实验。在220℃下，研究了水热碳化和微波碳化对超级电容器电极材料性能的影响。结果表明，掺杂豆粕和蛋清的食物垃圾能够实现良好的氮掺杂。在电流密度为1 A·g时，水热掺杂制备的掺杂碳的比电容高达220.00 F·g，远大于仅通过食物垃圾水热碳化制备的原料，这表明豆粕、蛋清和食物垃圾的水热碳化反应很好地促进了所制备碳材料的电化学性能。然而，当多种原料混合进行热解碳化时，不同原料在热解过程中无法充分混合，在氢氧化钾的蚀刻作用下，会出现严重的局部蚀刻和局部未蚀刻现象，导致所制备碳材料的孔径分布严重增加，电化学性能恶化。在电流密度为1 A·g时，这些制备的碳材料的比电容为157.70 F·g，而在20 A·g的高电流密度下仅为62.00 F·g。因此，本研究表明，对于制备相互掺杂的多个样品的超级电容器电极材料，水热碳化过程优于微波热解碳化过程。
