Preparation,Charaterization And Lithium Storage Performance Of Conductive Metal Organic Frameworks

2,3,6,7,10,11-hexahydroxytriphenylene?HHTP?has more effective functional groups capable of reacting with metal ions and better physical and chemical properties,and has become a kond of ligand material of conductive metal organic framework?Conductive MOF?in recent years.At present,these conductive MOF has been used as the electrode materials in energy related fields such as supercapacitors,sodium ion batteries,electrocatalysis et al.,and all enhibt superior electrochemical behaviors.Therefore,this study is committed to explore the applications of this conductive MOFs composed of HHTP and metal ions in lithium storage and and the mechanism.The main research contents are as follows:?1?Using the solvothermal method to prepare the Cu₃?HHTP?₂ nanowires and exploring its electrochemical performance.These nanowires can be observed by Scanning Electron microscopy?SEM?and shows a diameter of about 50 nm and a length of 500 nm.They echibited a discharge capacity of 631 mAh g^-1 at the current density of 200 mAh g^-1 and even approximately 381 mAh g^-1 at 2000 mA g^-1,along with striking capacity retention of 81%after 500 cycles at 500 mA g^-1.Moreover,a Cu₃?HHTP?₂ full cell assembled with LiNi_0.8Co_0.1Mn_0.1O₂?NCM811?as the cathode displayed a large energy density of approximately 275 Wh kg^-1 as well as excellent cycling behavior.These results manifest the promising application Cu₃?HHTP?₂ in advanced lithium-ion batteries?LIBs?.?2?Using the hydrothermal method to prepare the Co₃?HHTP?₂ nanowires and exploring its electrochemical performance.The morphology of Co₃?HHTP?₂ is similar to Cu₃?HHTP?₂,but due to the smaller crystal,there is not obvious diffraction peak in X-ray diffraction?XRD?.Specially,Co₃?HHTP?₂ also shows excellent performance as the anode material of LIBs,it not only displays a fast lithim ion diffusion rate,but also exhibits a specific discharge capacity of abot 577 mAh g^-11 after 300 cycles at the current density of 500 mA g^-1,and even at a large current density of 2000 mA g^-1,its specific discharge capacity can still resch 380 mAh g^-1.The Lithium-ion capacitors?LIC?prepared by mixing Co₃?HHTP?₂ with activated carbon?AC?at a ratio of 1:2.5 also shows high power density of about 10 kW kg^-1 at the energy density of about 64 Wh kg^-1.These results suggest the superiority of Co₃?HHTP?₂ as LIC anode material.?3?Using the hydrothermal method to prepare the M₃?HHTP?₂?M=Ni,Zn and Mn?nanowires,explor their electrochemical performance and lithium storage mechanism.Ni₃?HHTP?₂ shows better rate performance and high specific diacharge capacity of about 428mAh g^-1 at 2000 mA g^-1,which is higher than Cu₃?HHTP?₂ and Co₃?HHTP?₂.Furthermore,the newly formed Zn₃?HHTP?₂ and Mn₃?HHTP?₂ also exhibit good cycle stability,especially Zn₃?HHTP?₂ can maintain a specific discharge capacity of 391 mAh g^-1 after 1000 cycles at500 mA g^-1.Mn₃?HHTP?₂ can be charged and discharged for 500 cycles at the same current density and still remain stable.In addition,the lithium storage sites of such conductive MOF can be judged to be mainly benzene rings,pores and interlayers by non-in situ X-ray Powder diffractometer?XRD?,recycled X-ray photoelectron spectroscopy?XPS?and Transmission electron microscope?TEM?.This result will indicate the direction for the subsequent structural optimization and application development of such conductive MOFs.