Preparation And Capacitive Properties Of Aromatic Polycarboxylic Acid Coordination Polymers Based Electrode Materials

Coordination polymers(CPs),as a self-assembled organic-inorganic hybrid materials with metal ions/metal clusters as nodes and organic complexes as connecting units,which have great potential applications in gas adsorption separate and electrochemistry and other fields.It is an innovative research to prepare CPs based nano materials and study their application in electrochemistry.In this paper,12 novel CPs were synthesized by the reaction of aromatic polycarboxylic acid with transition metal ions under solvothermal conidtion.Besides,their structure and composition were analyzed and characterized by X-ray single crystal diffraction and thermogravimetry.Moreover,they acting as electrode materials were assembled into energy storage device and their electrochemical performance were systematically studied.The main contents and results are as follows:In this paper,CPs with different dimensions were prepared and mainly classfied into seven three-dimensional types and six two-dimensional types.The seven three-dimensional(3D)CPs include {[Cu2(TPTA)(H2O)2]·2DMF·NMP·4H2O}n(1),{[Co3(TPTA)]·1.5DMA·2CH3CN·H2O}n(2),[Mn3(H4TPTA)]n(3),[Zn3(H4TPTA)]n(4),{[Co(TPTA)0.5(4,4’-bbib)]·H2O}n(5),{[Mn(bipa-tc)0.5(1,4-bibb)0.5]·H2O}n(6),while the six two-dimensional(2D)CPs with layered network structures contain Ni(TPTA)0.5(1,4-bib)0.5(H2O)2]·CH3OH}n(7),{[Ni(TPTA)0.5(1,3-bimb)(H2O)]·NMP}n(8),[Ni(TPTA)0.5(1,4-bip)(H2O)2]n(9),[Ni(TPTA)0.5(4,4’-bbib)(H2O)]n(10),[Ni(bipa-tc)0.5(4,4-bipy)(H2O)2]n(11),{[Co(TPTA)0.5(1,4-bib)0.5(H2O)2]·CH3CH2OH}n(12).3D materials is recognized as the ideal candidates for energy storage materials due to the large specific surface area and unique pore structure.Thus 3D CPs(1~6)are introduced into supercapacitor(SC)system utilized as electrode materials.Among them,the CPs marked the current density of as 1 presented 0.5 A g-1)and the highest specific capacitance(406.0 F g-1 at capacitance2000 great test system,retention(90.6% after cycles)in the conventional three-electrode high porosity of 62.0% promoting effective which is attributable to the charge transfer and the rapid penetration of electrolyte.Furthermore,CPs 1 combined with AC construct the SC device as 1//AC and show a high energy density of 10.4 Wh kg-1 and power density of 613.7 W kg-1.Lastly,the capacitance of CPs 7~12 are 227.1 F g-1,311 F g-1,489.2 F g-1,642.2 F g-1,414.2 F g-1 and 264.3 F g-1 when J is 0.5 A g-1.After they are assembled into SC,the energy density is 8.36 Wh kg-1,11.8 Wh kg-1,16.6 Wh kg-1,21.5 Wh kg-1,11.5 Wh kg-1,9.85 Wh kg-1,respectively,and the power density is 501.3 W kg-1,375.6 W kg-1,564.6 W kg-1,432.2 W kg-1,621.6 W kg-1,585.3 W kg-1,respectively.The good electrochemical properties of CPs 7~12 are ascribable to the 2D layered structure,which is conducive to the rapid arrival of electrolyte ions from both sides to the active center of the electrode,thus significantly reducing the ion transport/electron transfer path and resistance.Besides,the nano channels between the lamellae promote the ion diffusion/electron transfer rate and the larger specific surface area improves the ion diffusion rate and provides more active sites for storing charges.