Preparation And Capacitance Performance Of Metal Organic Frame Compounds Derived From Carbon And Composite Materials

Metal-organic frameworks?MOFs?are playing an increasingly important role in the field of supercapacitors because of their advantages such as high specific capacity,adjustable aperture,and surface modification.However,when MOFs is used alone as electrode materials for supercapacitors,they have the disadvantages of the faster specific capacity decay and the lower electrochemical utilization,which limits their application and development in supercapacitors.With the help of the porous nature of MOFs,it can be used as nano filler or template to control the pore structure and specific surface area of polymer-based derived carbon,so as to prepare derived carbon materials of MOFs/polymer composite,At the same time,due to MOFs material itself is rich in heteroatoms and oxygen-containing functional groups,after carbonization,heteroatoms can be directly doped into the composite-derived carbon,thereby introducing pseudocapacitors and improving the energy storage properties of supercapacitors.The specific content and results of this paper are as follows:1. The ZIF-67/melamine formaldehyde resin composite material was carbonized at high temperature under the protection of argon to prepare a coral-like composite material?ZMFC?.ZIF-67 played a vital part in the sizes and dispersibility of melamine resin spheres,and the formation of coral-like structure.Besides,the influence of ZIF-67 dosages on ZMFC was investigated and the best preparation process was summarize through a series of characterization tests preparation process.When the added amount of ZIF-67 is 0.1 g,the specific surface area of the sample ZMFC-0.10 is as high as 200.64 m² g^-1.The high specific capacitance of 341 F g^-1 at 0.5 A g^-1 can still maintain 236 F g^-1 at a current density of 10 A g^-1,which indicates that ZMFC has excellent rate performance.After 10000 cycles of charge and discharge at 10 A g^-1,the specific capacity achieved 106%of the initial specific capacity.The excellent electrochemical performance of ZMFC is largely attributed to the coral-like morphology with rich porous structure and high specific surface area.2. The ZIF-8/glucose composite material was carbonized at high temperature under the protection of argon to prepare the nitrogen-oxygen double-doped porous carbon materials?ZGCC?.And the effects were systematically explored of ZIF-8dosage and carbonization temperature on the structure and electrochemical performance of ZGCC.The best preparation process was summarized through a series of structural characterization and electrochemical performance tests.When 0.50 g ZIF-8 was added,the high specific surface area of the ZGCC-0.50(495.95 m² g^-1)was obtained,as well as a superior content of heteroatoms of N?13.06 at.%?and O?7.96at.%?.In 6 M KOH electrolyte,ZGCC-0.50 exhibited the best electrochemical performance with a capacitance value of 321 F g^-1 at 0.5 A g^-1 and 230 F g^-1at 10 A g^-1,showing good rate capability of 71.6%.3. Using thiourea-formaldehyde resin riched in nitrogen and sulfur heteroatoms as the carbon source,ZIF-8/thiourea-formaldehyde-derived porous carbon material?ZTFC?was obtained by simple template method and carbonization treatment.The structure and electrochemical properties of ZTFC were characterized by using SEM,XRD,TG,XPS,and electrochemical tests.The results show that the presence of ZIF-8can limit the melt flow of thiourea-formaldehyde resin during high-temperature carbonization,and introduce advanced porous structure to increase the specific surface area.These structural advantages have a significant effect on improving the electrochemical performance of ZTFC.The samples of ZTFC-0.10 exhibits the best electrochemical performance,which owns the specific capacitance of 318 F g^-1 at 1 A g^-1 in 2 M H₂SO₄ electrolyte,showing good capacitance retention rate of 82.7%(263 F g^-1 at 10 A g^-1).Therefore,it has certain research value in the field of energy storage as electrode material.