| As an environmentally friendly energy device,supercapacitors,have attracted more and more attention and favored by scientists because of their advantages of fast charging,excellent ultra-low temperature effects,long cycle life and high power density.This energy storage process of the electric double layer supercapacitor does not cause expansion or contraction of the electrode material,and its cycle performance and safety are extremely high.Carbon-based materials are the main electrode materials for this type of capacitor.With the advantages of low cost,excellent stability and good conductivity,it has become the focus of researchers.The results show that the surface wettability of carbon materials can be improved by introducing heteroatoms into carbon-based materials.In addition,heteroatoms can form electrochemically active species and act as reversible Faraday redox reaction during charge-discharge process,thus increasing specific capacitance.In this study,melamine foam was used as a stationary carbon source and nitrogen source.Nitrogen doped carbon foams with abundant pore structure and high specific surface area were prepared by adding additional glucose as carbon source.?1?In this paper,melamine foam was used as carbon source and nitrogen source,cheap glucose was used as additional carbon source.Nitrogen-doped carbon materials were prepared by one-step carbonization method,moreover,the effect of glucose content on the morphology,pore size and electrochemical properties of the material was further explored.By comparing the electrochemical properties of the carbonized product NCF of melamine foam with the carbonized material NCs-1:20 loaded with glucose on the melamine foam,we found that in the three-electrode system,when the current density is 1 A g-1,the specific capacity of the NCs-1:20 material is 149.2 F g-1 and NCF material is 114 F g-1.This phenomenon indicates that the loading of glucose contributes to the electrical conductivity of the composite.By comparing the materials with different glucose contents,it is not difficult to find that as the content of glucose increases,the nitrogen content and specific surface area of the material decrease significantly and the electrochemical performance decreases also,which reflects the excess glucose load is not conducive to the rapid transfer of electrolyte ions.In addition,the best effect is when the melamine to glucose loading ratio is 1:20.?2?Based on the good electrochemical performance of nitrogen-doped carbon materials,a nitrogen-doped carbon foam with a richer pore structure and a higher specific surface area was prepared by a simple one-step carbonization and activation method using KOH.The effects of activation temperature on the morphology,pore size and electrochemical properties of the materials were also investigated.Finally,it was found that the ANCs-800 electrode material had the best electrochemical performance when the activation temperature was 800°C.At a current density of 1 A g-1,the specific capacitance of the ANCs-800 material can be as high as360 F g-1 and the NCs-1:20 is only 143.7 F g-1.This result indicates that the formation of a unique porous nitrogen-doped carbon material by KOH activation is successful.In the two-electrode system,when the current density is 0.5 A g-1,the specific material ANCs-800 has a specific capacitance of 387 F g-1 and an energy density of 24.2 W h kg-1.In addition,the material also has excellent cycle stability.When the material is charged and discharged for10,000 cycles,its specific capacity retention rate is still as high as 96.3%,which fully indicates that the porous nitrogen-doped carbon material has a great application potential in the field of supercapacitors. |
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