Carbon Material Composite Nickel-cobalt Hydroxide Electrode For Super Capacitor

Multi-walled carbon nanotubes-GO nanoribbons?MWCNTs-GONRs?can perfectly display their outstanding properties due to their unique 3D cross-linked structure,which integrates the properties of CNTs and GONRs.GQD is a small-sized graphene carbon point,which is widely used in many fields due to its excellent biocompatibility,stability,quantum limitation and boundary effect.In this work,the carbon material mentioned above will be used as a carbon source to synthesize high-performance electrodes for supercapacitors through a variety of experimental ideas?designing array layered structure or pretreating the carbon material to obtain functional nitrogen-doped carbon materials for composite?and different preparation methods.At the same time,the structure morphology and electrochemical properties of the samples were studied by various characterization methods and detection methods.The main research contents are as follows:?1?The hydrothermal method has the advantages of easy operation and easy control of crystal morphology.In this experiment,the velvety MWCNTs-GONRs/?-Ni?OH?₂electrode?MW-Ni?,the nano-needle array MWCNTs-GONRs/Co₃O₄ electrode?MW-Co?and the MWCNTs-GONRs/Co₃O₄/Ni?OH?₂ electrode?MW-Co-Ni?with pine core-shell array structure were prepared by simple hydrothermal method,respectively.This layered/core-shell design can effectively promote the diffusion of ions and increase the active sites of the electrode,thus enhancing the electrochemical performance.Their specific capacitance at 1 A g^-1are 1713.2,846.2 and 2654.7 F g^-1,respectively,and they also have superior stability to withstand thousands of cycles.After device assembly,MW-Ni//AC,MW-Co//AC and MW-Co-Ni//AC have the maximum energy density of41.23,38.23 and 74.85wh kg^-1,respectively,and high cycle stability at large current density.?2?Microwave method has advantages of uniform heating,quick response,easy to control.In this experiment,I synthesized flower-shaped histidine-functional graphene quantum dot/Ni-Co LDH?His-GQD/LDH?and histidine functionalized multi-wall carbon nanotubs-GO nanoribbon/Co-Ni LDH?His-MW/LDH?composite materials by selecting different histidine functional carbon materials and using microwave method in one step.It can be seen from the characterization that His-GQD/His-MW are evenly distributed on the surface of LDH.The synergistic effect of histidine functionalized carbon materials with LDH can effectively increase the specific surface area and conductivity of the composites,thus endowing the His-GQD/LDH and His-MW/LDH composites with high specific capacitance(1526 and 1674 F g^-11 at 1 A g^-1,respectively)and satisfactory cycle stability?82.36%and 83.33%capacitance retention,respectively?.The assembled His-GQD/LDH//AC and His-MW/LDH//AC have maximum energy densities of 48.89 and39.47 Wh kg^-1,respectively.After 6000 cycles at a high current of 10 A g^-1,the capacitance retention rate of the device did not significantly attenuate,and it could still maintain more than 90%.This work provides a practical experimental method for synthesizing histidine functionalized carbon derivatives with nickel-cobalt LDH by microwave method.