Preparation Of 2D-MOFs And Optimization On Their Performance Of Supercapacitor Application

Owing to the high power density and excellent cycle stability,supercapacitor has attracted more and more extensive attention and regards as a rising type of energy storage device.Metal organic frameworks?MOFs?,as a kind of burgeoning crystalline materials,are applied in many fields with the characteristics of large specific surface area,ordered crystal structure,abundant metal ion centers and convienient synthetic process.Compared to traditional supercapacitor materials,a large number of connected 3D channels are conducive to ion transport intersected in the structure of MOFs.Meanwhile,the abundant active components highly ordered crystal structure are beneficial to the conversion of electric energy and avoid the accumulation of active substances,respectively.Unquestionablely,MOFs is can be deemed to a potential electrode material for the supercapacitors application.In this paper,a series of MOFs materials and their deuterogenic complexes are directly used as electrode materials for supercapacitors to explore and improve the electrochemical performance were designed and synthesized.The main contents are as follows:?1?Isostructural Mn-MOF,Co-MOF and Ni-MOF have been prepared successfully through a facile solvothermal method with H₂PIA ligand.Structure of as-synthesized sample contains a lot of Lewis base sites such as nitrogen and oxygen atoms with the two-dimensional layered stacked structure.Compared to others MOFs,Ni-MOF showed superior electrochemical performance through electrical property tests and analysis with a capacitance of 611 F g^-1(at a current density of 1 A g^-1)and retained rate of 69.7%at 10 A g^-1.?2?On the basis of the first part,the electrode material was modified by different methods.Co-MOF/NF composite was synthesized on nickel foam through a facile solvothermal method.Not only can the direct growth of MOF on nickel foam facilitate the electron transfer process from nickel foam to the Co-MOF,but also improve mechanical stability of Co-MOF/NF composite.In addition,the Co-MOF/NF can remain the original two-dimensional layered stack structure,and the specific capacity of Co-MOF/NF was increased 555.66%compared with Co-MOF.Moreover,Cu-doped-Ni-MOF was synthesized by doping Cu²⁺into the lattice of Ni-MOF whose cycling performance was improved about 35%under maintaining the specific capacitance after 3000 cycles of charge discharge test.?3?A two-dimensional layered Ce-MOF was synthesized with the same H₂PIA ligand filled of a lot of uncoordinated Lewis base groups.Ni²⁺was modified into the pores and combined with the uncoordinated active sites to form Ni@Ce-MOF composite by ultrasonic exfoliation method.The specific capacity of Ni@Ce-MOF was increased to 921.05%compared with Ce-MOF.