The Research On The Application Of MOF-derived Porous Carbon And Nickel Oxide In Supercapacitors

Due to the advantages of high power density,fast charge-discharge capability,long cycle stability and environmental protection,supercapacitors have been widely used in the field of energy storage.Metal-Organic Frameworks?MOFs?are new type of porous coordination polymers assembled by metal ions and organic ligands.The derived materials have the advantages of controllable morphology,large specific surface area and abundant porosity,so they have great application prospects in the field of supercapacitors.However,considering the various constitutions and unpredictable architectures,how to design some novel MOFs for the synthesis of electrode materials with extraordinary electrochemical properties is still receiving much attention and challenging.The main research contents are as follows:1. In this work,three Cu-MOF 1 samples with tunable morphologies of rhombic,squama,trucated bipyramid have been synthesized under 0?,25? and 60?,respectively,which are further employed to initially prepare Cu@C composites by the calcination-thermolysis procedure.Then Cu@C composites have been etched with HCl and subsequently activated by KOH to obtain activated porous carbon?APC-0,25 and 60?.Interestingly,APC-25 presents a loose multilevel morphology of cabbage,and possesses the largest specific surface area(1880.4 m² g^-1)and pore volume(0.81 cm³ g^-1).The APC-25 electrode displays excellent specific capacitance of 196 F g^-1 at 0.5 A g^-1,and the corresponding symmetric supercapacitor cell achieves remarkable energy density of 11.8 W h kg^-1 at power density of 350W kg^-1.Significantly,five LEDs can be lighted up by six symmetric supercapacitor cell,which prove that APC-25 owns good actual application in energy storage devices.2. In this work,a lamellae Cu-MOF 2 with 2D?4,4?layer structure was successfully synthesized.Cu-MOF 2 is initially employed as precursors to prepare the Cu@C composite through calcination-thermolysis procedure.Then Cu@C is etched with HCl,and subsequently activated by KOH to obtain porous carbon nanosheets?PCNs?materials,which shows ultrahigh specific surface area(2491 m² g^-1)and pore volume of 1.50 cm³ g^-1.Significantly,the PCNs owns outstanding specific capacitance of 260.5 F g^-1 at 0.5 A g^-1under a load of 8 mg cm^-2.Symmetric supercapacitor cell based on PCNs achieves excellent specific energy density of 18.38 Wh kg^-1 at power density of 350 W kg^-1.Therefore,the PCNs are a competitive and promising candidate for preparing supercapacitor cells.3. As an energy dot,the ClO₄^-ion is introduced into one nickel metal-organic framework?Ni-MOF?,which appears as micron-scale lanterns.Then Ni-MOF was further calcined as the precursor,and the heating rate was set to 1,2,3? min^-1,respectively,to obtain a series of Ni O materials.It is found that the explosion results of ClO₄^-ions were significantly different at different heating rates.At 3? min^-1,Ni-MOF is well prilled into hierarchical cauliflower-like nanoparticles?Ni O-3?.Due to large specific surface area,supercapacitive properties of Ni O-3 are initially studied by a three-electrode system,which shows a prominent capacitance of 1863 F g^-1.Following,Ni O-3 is integrated with commercial activated carbon into an asymmetric supercapacitor cell,which exhibits high specific energy density of 38.4 Wh kg^-1 at the current density of 0.5 A g^-1.Significantly,asymmetric supercapacitor cell is really applied in lighting,fanning and vehicle,which shows that Ni O-3 has great practical application value as electrode material.